Tomato Fusarium Wilt

If your tomato plants wilted and yellow on one side of the plant or one side of a leaf, they have Fusarium wilt. Fusarium wilt on tomatoes caused by Fusarium oxysporumsp. lycopersici. It is a fungus soilborn found in the United States, especially in hot regions of the country. The organism is specific to tomato and many longlived in all regions of the United States. The disease develops rapidly in soils that are high in nitrogen and low in potassium. In addition, plants grown in sandy soil tends to contract the disease more often.

Symptoms

Wilting is the most characteristic symptom of infection by Verticillium spp. Symptoms usually appear on the lower leaves in mid-August when infected plants wilt during the warmest part of the day, and then recover at night. Leaf edges and areas between the veins turn yellow and then brown. In addition, infected plants often have a characteristic V-shaped lesion at the edge of the leaf occurring in a fan pattern. These foliar lesions can enlarge, resulting in complete browning and death of the leaves.

Verticillium wilt can be detected by looking for the presence of vascular streaking in stems near the ground. When cut longitudinally, Verticillium-infected stems show a light tan discoloration of the vascular tissue (Figure 1).

Fig - 1

These symptoms are similar to those caused by another fungus, Fusarium, but vascular streaking caused by Fusarium is generally darker and progresses further up the stem than streaking caused by Verticillium. Infected potato tubers may also show similar vascular discoloration occurring in rings, especially near the stem end (Figure 2). Although discolored, the tubers are safe to eat.

Fig 2

Wilt caused by this disease may be differentiated from drought-stress based on the portion of the plant that is wilting and on the location of wilted plants. Diseased plants often have only a portion of the plant wilting, such as one or two stems (Figure 3). 

Fig 3

In addition, diseased plants usually appear in patches within the growing area (Figure 4). Plants suffering from drought, however, are uniformly wilted and occur throughout the growing area.

Fig 4

Life Cycle

The fungi causing this disease overwinter in the soil as mycelium or on plant debris as microsclerotia. The fungi infect a susceptible host through wounds in the roots caused by cultivation, nematodes (microscopic worms), or the formation of secondary roots. This disease is considered a cool-weather disease, developing between 65° and 83°F.

Management

Because Fusarium and Verticillium fungi are widespread and persist several years in soil, a long crop rotation (4 to 6 years) is necessary to reduce populations of these fungi. Avoid using any solanaceous crop (potato, tomato, pepper, eggplant) in the rotation, and if Verticillium wilt is a problem, also avoid the use of strawberries and raspberries, which are highly susceptible. Rotate with cereals and grasses wherever possible.

Keep rotational crops weed-free (there are many weeds hosts of Verticillium).

Whenever practical, remove and destroy infested plant material after harvest.

Maintain a high level of plant vigor with appropriate fertilization and irrigation, but do not over-irrigate, especially early in the season.

Plant disease resistant tomato varieties, labeled V (for Verticillium) and F (for Fusarium). These disease resistance designations are usually shown in seed catalogues. Fusarium- or Verticillium-resistant varieties of eggplant, potato, and pepper are generally not available.

If soils are severely infested, production of solanaceous crops may not be possible unless soil fumigation is an option. See the Ohio Vegetable Production Guide (OSU Extension Bulletin No. 672) for information on soil fumigation.

Petunias & Petunia, Wave Hybrids Germination,Cultivation, Growing

Petunia x hybrida WAVE

Solanaceae Family

Wave Petunias are a popular group of hybrids valued for their large, colorful blooms and unique creeping growing habit. Spreading up to 4 feet, these plants add huge mats of color to gardens and containers. Unlike most petunias, these bloom without getting leggy by midseason. 

Origin : 

The species was first sent from South America to Paris in 1823. It was discovered in South America by the explorer James Tweedie, (after whom the genus Tweedia is named), who sent specimens to the Glasgow Botanical Garden in 1831. Most of the varieties seen in gardens are hybrids (Petunia x hybrida), they were among the first ornamentals to be bred for the bedding plant market in the 1950s.

• Characteristics :

Sunlight: full sun

Soil conditions : requires well-drained soil

Prefers moist but well-drained soil.

Special locations:outdoor containers,xeriscapes

•  Plant Traits

Lifecycle: annual

Ease-of-care: easy

Height: 0.66 to 1 feet

Spread: 1 to 4 feet

Bloom time:

1.     early summer
2.     mid-summer
3.     late summer
4.     early fall
5.     mid-fall

Flower color:

    violet

    white

    pink

Flowers are up to 4” wide and trumpet-shaped.

Foliage color: medium green

Foliage texture: medium

Shape: spreading mass

Shape in flower: same as above

Special characteristics:

•     non-aggressive
•     non-invasive
•     not native to North America - Hybrid with South American parents.

Growing Information

How to plant:

Propagate by seed - Sow the seeds indoors 10 to 12 weeks before the last spring frost, leaving the seeds uncovered as light aids germination. Pre-started petunias are readily available at retail outlets.

Germination temperature: 80 F

Days to emergence: 7 to 10

Maintenance and care :

Wave hybrids don't need deadheading or cutting back like many other petunias. Fertilize every two weeks until midsummer. 

Pests:

 Parasitic nematodes 

Diseases:

•     Oedema
•     Powdery mildew
•     Botrytis blight
•     Sclerotinia stem rot
•     Viral diseases 

Sowing :

To sow seeds in the house, from February 8 to 10 weeks before the last frost. Petunias bloom in the morning and covered with flowers are stunning. They like the sun and often bloom within two months from seed and continue throughout the season until killed by the frost. They are easily cultivated, requiring rich soil and full sun. They grow best in high-moisture areas with well-drained soils, but can adapt to most soil types. For Established the plants need  less maintenance require dry weather than other plants.

Seed 6 mm (¼ inch) apart in rows 7 cm (3 inches) mm, that's for sure stand (especially the corners), so it is not eaten with irrigation. Do not cover the seed, as the seeds need light to germinate. 

Provide light and constant warmth of 21 to 27°C (70 to 80°F)   respectively. In fact, the heat source from bottom to the use of the best results . F2 hybrids tend at the end of the previous germinate much better at about 27c (80f).  F2 hybrids tend to germinate better at the higher end, at around 27C (80F). The soil temp should not fluctuate and must not drop below 21°C (70°F). Finely mist and cover seed tray with plastic or paper to conserve moisture.

Need to check the compost for dryness regularly.  Add a little warm clean water from below, if this is the case, being careful not to over water. Dont use too much water ,can die seedlings, as it can spread "damping off fungi", and encourage other moulds and diseases.  

Germination :

Usually seed takes 10 to 21 days for germination and it depending on soil and temperature conditions. After sprout the seeds remove cover as soon as possible. Keep moist but do not use cold water as it lowers the soil temp and weakens tender seedlings.

Transplant and grow on in cooler conditions, around 13 to 16°C (55 to 60°F) for stocky plants when seedlings are large enough to handle.  Acclimatize to outdoor conditions for 10 to 15 days before planting out after all risk of frost, 30cm (12in) apart in a sunny spot on light well drained soil. For pot plants, transplant the seedlings into 7.5cm (3in) pots, grow cool, well ventilated and give plenty of light, but shade from direct sun.

Cultivation :

When plants are 5 to 10cm (2 to 4in) tall, and ground is warm, transplant to their final positions in pots or into the garden, spacing 20 to 30cm (8 to12in) apart. Plant should be  a full sun location. They will tolerate light shade but blooming will be reduced. Use a low-nitrogen/high-phosphorus fertilizer sparingly. Do not overwater or over fertilize, Overwatering will  kill the plants. 

After planting into baskets, when established give them a good spray from a watering can. The weight of the water flow will produce a perfect cascading habit.

Pinch or shear when 15cm (6in) tall and keep faded flowers picked, for denser plants and more flowers, 

Petunias are sticky and will attract greenfly so keep an eye on them. Don't over water in the winter and keep them well ventilated.

Site and soil :

The most important requirement for growing petunias successfully is a location with plenty of light. Petunias need at least five or six hours of good sunlight; they'll perform even better when located in full sun all day. The more shade they receive, the fewer flowers they'll produce. Impatiens are a better choice for blooming in shady places.

While soil needn't be terribly rich to grow good petunias, it must drain decently. It's always useful to improve garden soil by conditioning it with organic matter, such as baled peat moss, well-rotted leaf compost or manure.

Spread the organic matter two to three inches thick. Then incorporate it into the soil to a depth of eight to ten inches, using a rototiller or garden fork. This helps open up heavy clay soil, which improves drainage, but can also increase the ability of light, sandy soil to hold moisture and nutrients.

Fertilizer and water :

Work a balanced fertilizer such as 8-8-8, 10-10-10, or 12-12-12 into garden soil at a rate of two pounds per hundred square feet. Later--early to mid-July--begin to use liquid fertilizer every three weeks (weekly for "spreading" petunias). Once the plants have begun to spread, it will be much easier to water this solution into the soil than to side dress with dry fertilizer.

Incorporate timed-release fertilizer into the soil when planting window boxes or other containers. Otherwise fertilize regularly every two weeks with a liquid fertilizer meant specially for flowering plants. ("Spreading" types require weekly fertilizing.)

For a fertilizer recommendation tailor made to your specific garden conditions, have an accurate soil test run. Contact your local County Extension office or the Soil Testing Lab at the University of Minnesota for information.

Petunias tolerate lots of heat, and are relatively undemanding when it comes to water. Except for "spreading" types, which require frequent watering, thorough watering once a week should be sufficient in all but the worst weather. Leave sprinklers on long enough to soak the soil to a depth of six to eight inches every time you water. Hanging baskets and other containers also need more frequent watering, perhaps as often as daily, depending on their size and the volume of soil they contain.

Plant Uses : 

Window boxes, containers, tubs, hanging baskets and pot plants. 

How to Plant Flowers from Root Divisions (Perennials Only)

While the beginning of a flower from seed, transplanting from cuttings can be used for both annual and perennial flowers, only perennial plants can be propagated by root divisions.

Plant root sections have two purposes:

1.  It reinvigorates the flowering perennials currently in your garden, producing fuller plants and more flowers.

Why would remove a plant from the ground and cut its roots help rather than hurt it?

All year growth of a perennial says it continues to develop new roots and new shoots sprout. All those new parts of the plant to compete for the same water, sunlight and nutrients, so that each member gets proportionally less of it needs as time goes on. The distribution of the roots and replanting them allow each part of the now larger root system it needs to flourish get.

2. Free plants - Since each plant's root system some several times can be divided, it will give additional plants no extra cost.

Do not want to expand your flower garden? Share a neighbor! No neighbors? Add the extra compost heap.

In general, perennial flowering plants should be divided every three years, but there are exceptions. Rather than setting a division schedule, it might be better to take your plants and they split when all signs began to appear:

• Weaker or smaller tribes
• Fewer flowers
• Yellow or light green stems or leaves
• Plant begins to die at the center of forest

To divide the roots ...

1. Wait until it blossomed into the plant when your climate is cool and wet - usually in spring or autumn. This will vary from region and the perennial you share. If in the autumn, give the roots at least two months to repair themselves before the ground freezes.
2. Prepare the planting site ahead of time to the time of land to a minimum. The hole should be two times bigger than the original root system with a little seaweed fertilizer liquid is added to the hole in preparation for the new resident.
3. The plant water the day before you cut it.
4. Cut overhead grows to about 6 inches (15 cm) above the ground.
5. When digging the planting, keep the root ball together by digging with a shovel about a foot (30 cm) to the base of the plant and prying it from the bottom.
6. When drag it out of the ground, NOT shake any land.
7. Divide the roots based on the type of root system (indicated for each plant in our Flower Growing Guide):

• Planted - compact root system with shoots that emerge from buds to the original crown. Use a shovel or machete to cut the crown in as many pieces as you want, but be sure each piece has at least a few buds attached.
• Spread - roots are relatively shallow, spreading away from the original crown and is separate from the original crown with a partially separate root system. Just pull each individual root system apart with your hands.
• Rhizome - very thick stems that spread away from the original plant (Ginger is a rhizome). Use a knife to divide them into sections, each with a few bumps.
• Root tubers - a "modified lateral root" that was converted to a food storage organ (a yam is a tuber). They serve nutrients for plants using storage off-season.

8.  Plant the divisions serve with the crown just above its previous level above the ground.

9.  Water and beat down the ground to the point that there is probably no underground holes remaining. The level of the crown above the ground now at the point of the original plant.

10.  Keep the soil moist consistently for at least the next few weeks.

How to Plant Flowers by Transplanting

Transplant refers to taking a pre-mature planting and replanting it in your garden.

When purchasing plants for transplanting, look for the following characteristics:

• General "healthy looking" plants
• White and "fleshy" roots (as opposed to brown roots) that the container fill
• Dark green leaves
• Plants without full of flowers (they will be much better a few weeks after planting seems)

When transplanting flowers ...

• Do as early as possible in the spring after all danger of frost passes
• Harden off your flowers - Flowers bought for transplanting tar nurtured in a greenhouse because they were seeds, and they need to gradually be introduced to the harder outside environment before going into the ground. This process is known as "hardening off plants."

Hard on your flowers:

• Day 1 - Let them out for 4 hours in the sun levels guidelines each plant (ie the sun, partial shade, full shade) match
• Day 2 - Let them out for 6 hours
• Day 3 - Leave them outside for 8 hours
• Day 4 - Transplant in your garden or flower bed

1. The day before transplant, watering the plants with about an inch (2.5 cm) of water
2. Just before you are ready to plant, remove the soil from the container some with roots and soil structure left intact. If there are several flowers growing in the tray, cut the ground between the plants for removing each plant.
3. If the roots tightly around the ground some make several shallow cuts around encouraging the forest to the roots to grow out into the soil
4. Lightly wet the hole before transplanting to the point that it consistently moist (about the texture of a wrung-out sponge)
5. Plant at a depth corresponding to the depth of the plant when it was in the container (same goes for planting peat pots ... puts the whole peat pot in the ground so that the ground level of the peat pot matches the ground Garden's)
6. After placing the wood in the soil, packing the surrounding soil around the bush then fertilize with a liquid organic fertilizer.
7. Until established (at least a few weeks), keep the plants well watered to the point that the surrounding soil remains consistently moist.

Crown Rot Identification And Tips For Treatment

Crown Rot is caused by the Phytophthora fungus, which attacks the roots and, most notably, the crown of African Violets. African Violets are most susceptible to Crown Rot when allowed to sit in soil that is heavy and soggy. In almost all cases, Crown Rot is fatal. The best control for Crown Rot is, therefore, prevention.

Distinguishing Symptoms

• Crown is mushy. It may appear translucent brown with a soft, jelly-like consistency.
• Crown darkens. It appears brown or black in color. 

These symptoms indicate that the crown is rotting. If your African Violet has these symptoms, it probably has Crown Rot.

Other Symptoms

• Crown has a weblike substance on it. (Note: This substance should not be confused with the web left behind by Spider Mites, which clings to the flowers and plant hairs of the leaves. Nor should it be confused with the "cotton" specks which characterize Leaf Mealy Bugs.)
• Leaves have a weblike substance on them.
• Leaves darken. They appear brown or black in color.
• Leaves wilt. They may appear translucent brown with a soft, jelly-like consistency.
• Plant growth is slow. 

BIOLOGY

Phytophthora species are soil-inhabiting pathogens that are favored by wet conditions. Although previously considered fungi, Phytophthora species are now considered to be in a separate classification called oomycetes. Species of Phytophthora produce resting spores that survive for years in moist soil in the absence of a suitable host. However, if the soil is completely dried out, these spores are less likely to survive for more than a few months. When a host is nearby and free water (water in soil pore spaces) is present in the soil, resting spores germinate to produce motile spores that can directly penetrate roots, branches, or crowns as long as free water is present. Wounds are not required for infection. Resting spores, decaying host tissue in the soil, and active cankers (disease-infected dead, sunken lesions in plant parts) can all be sources for new infections. The pathogen can be spread in splashing rain or irrigation water, in surface irrigation, and runoff water, and by movement of contaminated soil, equipment, or plant parts. Flooded and saturated soil favors the spread of Phytophthora to healthy plants.Some Phytophthora species are favored by warm weather, some by cool weather. Root rots of avocado, citrus, and tomato are favored by warm conditions, developing most extensively in late spring and early summer. Decay of crown, trunk, and branches of other tree species are favored by cool, wet conditions. These decays develop most rapidly in late fall and early spring.

Treatment

The most important factor in reducing the threat of Phytophthora rot is good water management. Avoid prolonged saturation of the soil or standing water around the base of trees or other susceptible plants. Irrigate only as much and as often as necessary; in an orchard, keep track of the soil moisture around each tree and water only when necessary. If you irrigate trees with sprinklers, use low-angle sprinkler heads and splitters to avoid wetting the trunk and lower branches. If using a drip system, place the emitters at least a foot away from the trunk. Avoid planting susceptible species on poorly drained or shallow soils. Water stress and/or salinity make some plant species more susceptible to infection when wetted subsequently by irrigation or rains.For all vegetable and orchard plants, provide good soil drainage. Good soil drainage is best provided before planting. Drainage should be plentiful to the rooting depth of the plants, generally 3 to 6 feet for trees, 2 to 4 feet for shrubs, and 1 to 2 feet for bedding plants. During favorable weather you do not want the roots and crown of a plant to remain wet for the 4 to 8 hours that are required for Phytophthora to infect the plant.Provide adequate drainage by breaking through soil compaction and hardpan. In poorly drained soils, or in an area where you know Phytophthora is present, consider planting trees and shrubs on mounds. The mounds should be 8 to 10 inches high. Planting depth after settling should be no deeper than as received from the nursery, with the upper roots near the soil level and the graft union well above the soil line. Do not install irrigated turf around the base of trees, remove all weeds, and do not water the crown area directly. Never cover the graft union with soil or mulch. If you are not sure where the graft union is, ask someone at the nursery to show you and mark it. Raised beds provide good drainage in vegetable garden situations also. Group plants according to their irrigation needs. Separate those needing frequent, light irrigations, such as potatoes and strawberries, from those needing infrequent, deep irrigations, such as tomatoes and melons. At the first signs of aboveground symptoms, examine the tree at the soil line for crown rot. Carefully cut away bark that looks affected. If crown rot is present, trees can sometimes be saved by removing soil from the base of the tree down to the top of the main roots and allowing the crown tissue to dry out.

Sanitation

It may be possible to slow the spread of Phytophthora within an orchard by avoiding movement of infested soil, water, and plant parts from an area where Phytophthora rot has developed. Surface and subsurface drainage water and anything that can move moist soil can carry the pathogen to a new area, including boots, car tires, and tools. If the physical setting allows drainage water to flow from infested to uninfected areas within the garden during wet weather, consider putting in drains to channel the water away from healthy plants.

Selection of planting stock

Plant only certified nursery stock from a reputable source, and choose the most resistant rootstocks or varieties available for your area. Less susceptible rootstocks or varieties are available for almonds and stone fruit, apples, cauliflower, and strawberries. Carefully select individual plants that are free of symptoms and/or that come from healthy lots of material.

RotationIf tomatoes have been affected by Phytophthora root rot, avoid planting tomatoes or other susceptible plants such as eggplant or peppers in the same soil for at least one or two seasons. Plant a resistant crop such as corn instead, or leave the soil unplanted and do not irrigate, but keep it well worked to allow the soil to dry as deeply as possible. Different species of Phytophthora attack beans and cole crops, so these plants can be substituted as well. Consult a nursery or farm advisor for possible alternatives in your area.

Chemical control

The most effective way of preventing Phytophthora rot diseases is to provide good drainage and to practice good water management. Along with the appropriate cultural controls, the fungicide fosetyl-al (Aliette) may be used on a number of ornamental plant species to help prevent Phytophthora infections. When applied as a foliar spray it is absorbed by foliage and moves into roots. However, do not rely on fungicide applications alone to control root and crown rot diseases.

Prevention

Prevention is always your best bet for successfully controlling Crown Rot. By adhering to the following guidelines, you will give your African Violets the best chance for eliminating any threat of Crown Rot.

Do not overwater. This is the greatest danger to African Violets. Overwatering leaves the soil soggy, a condition that is ripe for the development of Crown Rot. Water just enough to keep the soil damp. Always allow any excess water to drain. If you are using a self-watering device, which employs capillary wicking, make sure the pot is not in direct contact with the water. Also, it is strongly recommended that you only use wicks supplied by the manufacturer of the watering device.

Do not let the soil dry out completely before watering. Repeated, sudden changes in the availability of water can cause the same effects as overwatering.

Do not use a pot size that is larger than what your African Violet needs to form a tight rootball. If the pot size is too large, your Violet will not be able to absorb all the water, leaving the plant susceptible to the soggy conditions in which 

Crown Rot thrives.

Make sure the pot you use provides adequate drainage. If you are using a plastic pot which has no holes, you can easily add holes yourself with a soldering iron or by simply heating up a screwdriver and pushing it through the bottom of the pot. If you are using a terra cotta pot which has no holes, you can add holes with a drill. For 4-inch pots, use a 1/8-1/4 inch bit and drill from the bottom. Do not press too hard. Go slowly and let the drill do the work.

Use a light, porous potting soil. An ideal potting soil will consist of block-harvested, sphagnum peat moss. Such a potting soil allows any excess water to drain away from the roots. Be sure to pasteurize your potting soil.

Maintain good air circulation around your plants. Keep your growing area clean, and remove spent flowers and leaves as you find them.

Finally, you should strongly consider using a recommended self-watering device. Such devices use capillary action to draw the right amount of water into the soil. This prevents both overwatering and underwatering. For miniatures, there is the MiniWell (fits 1-inch pots) and the Optimara WaterShip (fits 2-inch pots). For larger African Violets, there is the MaxiWell (fits 4-inch pots) and the Watermaid (fits various sizes up to 6 inches.) Each of these self-watering devices is available at a number of hardware and discount stores. In addition, they can also be ordered online from the Selective Gardener, a mail order supplier that specializes in plant care products for African Violets.

Important Note on the Use of Pesticides

Please note that almost all pesticides are formulated for specific uses and conditions. When applied incorrectly, pesticides can cause ill health or damage to plants. Therefore, when using any kind of pesticide or chemical treatment, 

always apply as indicated on the product label.

Crown Gall Disease and Treatment

Crown gall is a plant disease caused by the soil-occupied bacterium Agrobacterium tumefaciens. The bacterium causes abnormal growths or galls on roots, twigs and branches of Euonymus shrubs and other mainly in the rose family. The bacteria stimulate the rapid growth of plant cells that lead to the galls. In addition to being unsightly, weaken the galls and hamper the growth of the plant. Although galls the flow of water and nutrients to the roots and branches can disrupt, they usually do not total plant death. The disease can spread to other susceptible plants through contaminated soil and tools. Most chemical treatments are not effective.

The galls on forsythia, viburnum, high bush blueberry American elm, HICKORY, maple, oak, and privet believed to be caused by a fungus, Phomopsis sp. Since its cultural controls are the same as for bacterial crown gall, both discussed herein. Chemical treatments will differ. Chemical treatments for both are of very limited value to the home gardener. Only those associated with bacterial crown gall is addressed.

Symptoms

Crown gall first appears as small overgrowths on the stem (trunk), crown, and roots – usually near the soil line, frequently at a graft union (Figure 1). On plants such as poplar and willow, the galls may appear on branches that are several feet above the ground. At first, the gall or tumor is white or flesh-colored, more or less round, and quite soft and spongy. The enlarging gall gradually develops an irregular, convoluted, rough, corky surface and a hard woody interior. The outer tissue gradually darkens. The galls may vary from pea-size to more than a foot in diameter and may weigh 50 pounds. Gall tissue gradually rots from secondary organisms. Tumors develop again in the same places the following year, or part of the gall may decay and slough off, with new tumor tissue developing in other parts of the same gall. On some host plants, secondary tumors develop at points several inches above or below the primary gall.

When the infection is severe, infected plants lack vigor, their leaves are stunted and may turn yellow or red, and the shoots often die back. As the galls continue to enlarge, plants may wilt and die.

Disease Cycle

Once introduced, the crown-gall bacterium overseasons in diseased tissue and in soil, where it lives as a saprophyte in organic debris for several years. The bacterium is spread in soil water or by rainsplash, and thus infects new plants.

Penetration occurs only through fresh wounds (less than 24 hours old). The wounds can be made during pruning, cultivating, transplanting, and budding or grafting. Wounds may also be caused by chewing insects, nematodes, or other animal pests. After entry, the bacteria multiply in the intercellular spaces and stimulate a rapid increase in plant cell division and an abnormal enlargement of the surrounding plant cells. In warm weather, when the host plant is growing rapidly, a small enlargement can often be seen 10 to 14 days after infection. As the rapid and irregular division and enlargement of host cells continues, the normal differentiation of cells within the tumorous growth decreases. This results in incomplete and disorganized water- and food-conducting tissues. When a gall is unable to obtain enough water and food to maintain itself, the enlargement ceases, decay commonly begins, and the outer, dead tissues slough away. The breakdown of the outer tumor tissues releases crown-gall bacteria back into the soil, where they can be carried in the water to infect new plants.

The crown-gall bacterium produces a tumor-inducing principle (TIP), a bacterial Ti-plasmid DNA (T-DNA), that is transferred and incorporated into wounded host cells, altering their hormonal balance. Normal plant cells are converted into tumorous cells, which are induced to manufacture more TIP and pass it on to their daughter cells. These daughter cells continue to enlarge and divide in an uncontrolled manner – free of the crown-gall bacteria. Strains or physiologic races of the crown-gall bacterium differ in virulence and host range; hence, the type and amount of tumor tissue that develops differs.

Control

1. Plant only certified, disease-free nursery stock that has a smooth graft union and is free of suspicious overgrowths or enlargements on the roots and stems. Budding, rather than grafting, reduces the chance of infection.

2. Carefully dig up and destroy all severely infected plants, especially woody ones.

3. Do not replant the same type of plant in the same spot for at least five years. Corn, small grains, grasses, onions, asparagus, and cowpea are immune.

4. Dip tools used for grafting, budding, and pruning in liquid household bleach between cuts. Prepare a fresh solution several times each day, using one part of bleach mixed with four parts of clean water.

5. Treat seeds, seedlings, cuttings, and bare-root plants. Excellent control of most strains of the crown gall bacterium has been obtained by soaking germinated seeds and dipping or spraying nursery seedlings, cuttings, or bare-root rootstock plants in a suspension of a nonpathogenic (or antagonistic) bacterium: strain 84 of Agrobacterium radiobacter, registered by EPA and available commercially as Galltrol-A sold by AgBioChem, Inc., 3 Fleetwood Court, Orinda, CA 94563. The nonpathogenic bacterium colonizes wounds, such as those made by root prunings, and thus prevents certain strains of the crown-gall organism from infecting the wounds.

6. Use resistant rootstocks. Peach rootstock S-37, certain Malling rootstocks for apple, and Japanese apricot (Prunus mume) are resistant to crown gall.

7. Sterilize the soil in greenhouses with steam (180 F or 82 C for at least 30 minutes at the coolest spot) or a soil fumigant such as methyl bromide, Vorlex, or chloropicrin, after first removing all woody roots and stems. If using a soil fumigant, carefully follow all the manufacturer's directions and precautions.

8. Avoid wounding plants while transplanting, cultivating, and mowing.

9. Protect roses, boxwood, young trees, and other susceptible plants against winter injury. Follow local recommendations. Fertilize and water properly to keep the plants vigorous.

10. Control chewing insects. Follow the recommendations of Extension Entomologists at the University of Illinois. This may mean treating the soil with an insecticide, as well as spraying or dusting the plants at appropriate times.
11. Sterilize the soil. Soils known to be infected with crown gall bacteria can be sterilized using chemicals, heat, or antibiotics. This is not practical for most home gardeners. A biological control has been introduced using a bacterium, Agrobacterium radiobactor strain 84. This bacterium was discovered to be antagonistic to crown gall bacterium. It is available for use as a preplant treatment by dipping nursery stock in a suspension of the live bacteria in water.

Care of Your Cactus & Propagation

We have compiled some general information about the care and maintenance of cacti and succulents in the following cultural notes. Use these notes as a basic and useful reference guide. Keep in mind that they do not delve into the details, but rather give a broad, general scope of cacti and succulents great.

For further information, you should consult your library for books on cacti and succulents. And you have the plants you grow observe, as they will be your best teachers.

Cacti and succulents, even if they are tough, adaptable plants, not "thrive on neglect." Instead, they consist of neglect, but thrive on tender loving care.

Light Requirements for Cacti & Succulents

Indoors

Give cacti and succulents the brightest light or sunniest window that you can provide. Most cacti and succulents are not happy in shady corners or north-facing windows as they need at least four to six hours of strong light daily if they are grown indoors. Plants with inadequate light may stretch (skinny growth). 

Outdoors

Some cacti and succulents can tolerate full sun. However, it is important to realize that during the hottest days of summer, when the solar radiation exceeds 11,000 foot candles, all plants would welcome some respite from the harsh afternoon sun. Many cacti and succulents prefer to be positioned in an area that receives morning sun, and is protected from the stronger afternoon rays. Some cacti can even sunburn, as in the case of the spineless or naked cacti, unless given some shade in the hottest part of the day. Reddish discoloration, either in part or on the entire plant, is usually the result of overly strong solar radiation. Remember that most cacti and succulents receive shading from grasses, shrubs or trees in their natural habitat, especially when they are young.

Your cacti and succulents will do nicely on a sunny windowsill or very bright spot indoors. However, for those of us not fortunate enough to have sunny windows and rooms, or mild winter climates where plants can be kept outdoors, there is another alternative. Plants can be grown under artificial light using fluorescent tubes. Don't attempt to use regular bulbs as incandescent light is not the proper light spectrum to maintain plants. For a few plants, use two 40-watt fluorescent tubes, either 24 inches long or 48 inches long, depending on the number of plants. Best is one cool white tube or daylight tube and one warm white tube. This will cover the necessary light spectrum needed for plants.

For handling and transplanting smaller plants, thin rubber gloves can be used to protect the fingers. Tongs that have been wrapped with tape or other material to prevent damage to the plant also work well. Larger plants can be handled with a short section of hose wrapped around the plant, or a sling made from a rolled newspaper can be used. 

Water

The general "Rule of Thumb" is: "When you water, water well." However, with succulent plants you must be careful to make sure the plant needs water. Feel the weight of the pot when just watered and when it is dry. A totally dry pot weighs considerably less and is one sign of a thirsty plant. Feel the soil at least one inch down and if the soil is dry it is time to water the plant. Let the water thoroughly drain through the roots and out the bottom, making sure the entire pot of soil is saturated. Drain thoroughly; never let plants sit in water. Use a soil mix that drains well and allows some drying out between waterings. Top dressings, such as small pebbles or coarse gravel, offer quicker water penetration, slower water evaporation, elimination of a crust on the top of the soil, and a neat, attractive appearance. When plants are vigorously growing and blooming, they will need more water. During their non-growing or resting stage, usually in cold winter weather, they will need very little water.

Soil

For practically all intents and purposes, any good cactus and succulent mix, prepared and bagged, and available in many nurseries and garden shops can be used for your cacti and succulents. Or, you can use a high quality planter mix or humus. For this, add two parts perlite or pumice and one part washed building sand. Adjust the ratios according to your growing conditions, climate and the plant in question.

Fertilizer

Most succulents and cacti are benefited by the addition of diluted liquid fertilizer added to the water every second or third watering during their growing season. Any standard houseplant fertilizer with balanced amounts of nitrogen, phosphorous and potash (20-20-20) can be used. It is also convenient to use one of the slow release granular fertilizers. To induce bloom and improve flower size, a fertilizer with low nitrogen and high phosphorous content can be used. Always dilute more than the stated instructions advise, as recommended dosage is too strong for these plants. One caution! If your plants are growing too lushly and/or are losing their characteristic shape, this may be the result of over-fertilizing. As a rule, it is safer to under-fertilize than over-fertilize. We do not recommend fertilizing Mesembs or Stapeliads.

Proper proportions of good drainage, generous but infrequent waterings, regular, diluted feedings, good light and fresh air are the basic needs of your succulent plant.

Temperature

In the winter time, keep your cacti and succulents in temperatures above freezing. They will go dormant and manage just fine in night time temperatures of 35° to 40°F.

Your more tropical succulents like Adeniums, Euphorbias, Epiphyllums, Rhipsalis, Stapeliads, and Zygocactus prefer warmer night time temperatures of between 50° and 60°F. However, if you harden them off by watering less in the fall, they will tolerate temperatures in the mid-thirties.

Other less tropical succulents, like many cacti, Sempervivums, Sedums and Agaves can tolerate lower night time temperatures into the mid-twenties (or less) when they have been gradually acclimated to cold weather.

In the summer, protect your cacti and succulents from extreme heat. If temperatures reach over 100°F, be sure to shade your plants and provide air circulation. When it is both humid and hot, it is particularly important to have good air circulation and careful watering to avoid fungus and rot problems. 

Transplanting

Your newly acquired plants are established in their present pots, but their roots systems have not used all of the space in their pots. They should live and grow in these same pots for at least another few months to a year before re-potting will be necessary. When transplanting, choose one pot size larger. Excess soil in too large a pot may cause soil to sour before roots can grow into and utilize it. Gently tap the plant out of its present pot. Gently brush or scrape away some of the old soil around the root ball, taking care not to disturb the center of the root ball or to break roots. Put some soil mix in the new pot and place the plant on top. Gently fill in around the sides; keep the plant at the same level as it was in the old pot. Let the plant stay dry a few days. This precaution will allow any roots that are damaged or broken during the transplanting process to heal and callous over before watering, avoiding rot of broken roots. When watering, let drain thoroughly.

For handling and transplanting smaller plants, thin rubber gloves can be used to protect the fingers. Tongs also work well. Larger plants can be handled with a short section of hose wrapped around the plant, or even a rolled newspaper can be used.

Propagation

Propagation of Succulents by Seed:

Some succulents, such as Kalanchoe longiflora, and Kalanchoe blossfeldiana are self-fertile (not needing another plant to produce seed). The swollen area that forms at the base of the flower after flowering is called the "fruit" and contains the seed. Other succulents can be cross-pollinated (requiring 2 plants, and where the pollen of one plant is used to pollinate another flower on another flower (known as "cross-pollination"). Usually this is accomplished by bees or other insects, but a curious owner can purchase a small sable hair paint brush and try his or her hand at producing seed to create new plants! For many succulents, the seed is a minute cinnamon-colored "dust". Germination of the seed requires a sterile, fine particle soil mix, heat (approximately 75 to 80°F), reduced light and maintenance of even moisture without being soggy ~ in other words, somewhat analogous to an incubator. A pot is prepared with the fine particle soil mix and is watered thoroughly. The succulent seed is then dispersed on top of the soil, allowing spaces between the seed so that the seedling will have room to grow. (Succulent seedlings are tiny at first, usually less than an 1/8" of an inch in diameter, and, depending upon the species, remain that small for months). The seed is then covered very lightly with a fine particle "top dressing" (such as the same soil but sifted). The seed pan should be watered daily with a very fine mist, making sure that only the top surface is allowed to dry somewhat in 24 hour intervals. Seed should begin to germinate within two weeks, but will appear as tiny bright green dots. As the seedlings approach 6 weeks of age, they can be gradually "weaned" from the water. At this time, the seedlings can be watered every other day except in very hot weather. Depending upon the variety, the seedlings can be "pricked" out at 6 months to a year of age and put in small pots.

Propagation of Succulents by Cuttings:

Use a sharp, sterile knife to prevent tissue damage to the plant, but be careful not to damage your own tissue!

For succulents, it is best to cut the stem to create a cutting that is 2"-3" in height (very small cuttings can often desiccate before rooting).

Allow the cutting to callous for several days to a week (depending upon ambient climate). During this time, a "callus" will form at the cut area. This "callus" is very analogous to the scab that the human body produces for cuts and scrapes. This "callus" or scab provides a two-fold barrier to protect the plant or animal. Fluid cannot leak out (which could lead to desiccation) and bacteria and fungus cannot enter (which could lead to serious disease). After the callus has formed, plant the cutting in a soil mix with extra perlite. The extra perlite will allow the aeration necessary to enable production of healthy roots. Sometimes, if you wait a bit too long before planting your cutting, it may produce "aerial" roots, which are actually capable of absorbing water! This is merely the plant letting you know that it is time to plant it!

 Propagation of Succulents by Leaves:

Another way to propagate some succulents is by leaf cuttings. This procedure will not work for all succulents, but will be very successful with many. It is necessary to very carefully detach a leaf from the stem, making sure the leaf is detached very cleanly, and not torn away. The leaf should be placed in a cool, shady place for several weeks to a month until a tiny "plantlet" begins to form at the base of the leaf. The leaf can then be carefully planted in a porous soil, and should not be allowed to dry completely while the roots form. This may take a few weeks. When the leaf feels "anchored" into the soil, and the "plantlet" begins to grow, the plant can gradually be given normal watering.

There are some plants in the Kalanchoe family that have a fascinating strategy whereby they produce their own "plantlets". Kalanchoe tubiflora, Kalanchoe delagoense, Kalanchoe fedtschenkoi and others produce "plantlets" along the margins of their leaves. When these "plantlets" grow a bit heavy, they begin detaching from the leaves and fall to the ground whereupon they root and produce new plants!

 Propagation of Succulents by Tissue Culture:

This method is only for those with access to a laboratory, but it is a method of producing many plants fairly rapidly from the cells of just one plant. In this process, cells are isolated from plant tissue. Research is done to determine what percentages of various hormones and nutritive elements are required by that particular type of plant. The cells are then placed on agar in petri dishes, and are "transfused" with the hormone and nutrition liquids. The environment must be extremely sanitary and must be kept at a constant humidity and warm temperature (around 70 degrees Fahrenheit). The single cells begin to divide, and produce more cells which become "specialized" to perform various functions, leading to the formation of a new, complete, fully functioning plant from a single cell. Tissue culture propagation is very akin to "cloning".

Propagation of Cacti by Seed:

Cacti can be propagated by seed. Some are self-fertile (not needing another plant to produce seed). The swollen area at the base of the flower after flowering is known as the "fruit" and contains the seed. Other cacti can be cross-pollinated (requiring 2 plants, and where the pollen of one plant is used to pollinate another flower on another flower (known as "cross-pollination"). Usually this is accomplished by bees or other insects, but a curious owner can purchase a small sable hair paint brush and try his or her hand at producing seed to create new plants! The seed of cacti differs greatly; some have seed that is so small that one thousand seeds fill a thimble and others, such as the Pachycereus pringlei, have seed that require a sandwich-sized baggie for 10,000 seeds. Germination of the seed requires a sterile, fine particle soil mix, heat (approximately 75 to 80°F), reduced light and maintenance of even moisture without being soggy ~ in other words, somewhat analogous to an incubator. A pot or flat is prepared with the fine particle soil mix and is watered thoroughly. The cactus seed is then dispersed on top of the soil, allowing spaces between the seed so that the seedling will have room to grow. (Cacti seedlings are tiny at first, usually less than an 1/8" of an inch in diameter, and, depending upon the species, remain that small for months). The seed is then covered very lightly with a fine particle "top dressing" (such as the same soil but sifted). The seed pan should be watered daily with a very fine mist, making sure that only the top surface is allowed to dry somewhat in 24 hour intervals. Seed should begin to germinate within two weeks, but will appear as tiny bright green dots. As the seedlings approach 6 weeks of age, they can be gradually "weaned" from the water. At this time, the seedlings can be watered every other day except in very hot weather. Depending upon the variety, the seedlings can be "pricked" out at 6 months to a year of age and put in small pots.

 Propagation of Cacti by Cuttings:

Cacti can be a bit more problematic as they can be more susceptible to various bacteria and fungi. Some cactus, such a Chamaecereus species and hybrids (commonly known as "Peanut Cactus"), are easily propagated as the joints of these plants detach very readily, leaving very small "open" or susceptible areas. Other examples of cacti that are rather easy to propagate are the Lobivias and Echinopsis, which also have offsets or "pups" that can be easily detached, and Opuntias, which have "ears" or segments that are easily detached. Other cacti, which do not have natural "detachment points", such as a Cereus or other columnars, will require a larger cut with a knife, thereby leaving a larger area susceptible to bacteria and fungi. It is advisable to allow any larger cut, depending upon the girth of the cut, more time to "callous" and form the callus tissue that is similar to a "scab". A week to 10 days should be sufficient. A further preventative measure requires dipping the newly cut cutting in a rooting hormone powder (available at garden centers). These rooting hormones often contain a fungicide which will help to prevent rot. After time necessary to "callous" has elapsed, plant the cutting in a porous soil mix and water lightly in about a week. Water occasionally until signs that the plant has begun to root are apparent ( such as roots at the base or some new growth at the tip. After the plant has rooted, regular watering can be resumed.

Propagation of Cacti by Tissue Culture:

Cacti can also be propagated successfully by tissue culture. This method is only for those with access to a laboratory, but it is a method of producing many plants fairly rapidly from the cells of just one plant. In this process, cells are isolated from plant tissue. Research is done to determine what percentages of various hormones and nutritive elements are required by that particular type of plant. The cells are then placed on agar in petri dishes, and are "transfused" with the hormone and nutrition liquids. The environment must be extremely sanitary and must be kept at a constant humidity and warm temperature (around 70°F). The single cells begin to divide, and produce more cells which begin to become "specialized" to perform various functions, and a new, complete, fully functioning plant is formed from a single cell. Tissue culture propagation is very akin to "cloning".

Propagation of Cacti and Succulents by Grafting:

One other method that is used for propagation is grafting. Grafting is a process that unites one cactus with another cactus (usually one that grows faster or is less problematic). This process is often utilized in the nursery industry to quickly increment numbers of a newly created or discovered plant. The plant that sits on top of the other plant is known as the "scion", and is connected vascularly ( in other words, all water and nutrients ascend the vascular system of the lower plant into the vascular system of the upper plant at the point of unification. The lower plant, known as the "stock" is always the strongest and fastest growing plant, has its roots into the ground, where it absorbs nutrients for both plants. The upper plant benefits greatly from this unification; it grows faster, is now immune to such diseases as root rots that previously may have plagued the plant when it was on its own roots, and oftentimes offsets more readily than when on its own roots. One last unique benefit of grafting concerns those plants born without chlorophyll. Chlorophyll is the material in the plant that enables photosynthesis (the process by which plants create the energy necessary for new growth and other processes). Chlorophyll also contributes to the green color of plants. But occasionally, a plant is born without chlorophyll (and is known as achlorophyllus) or is born with very small amounts of chlorophyll. These plants can survive for a while on their own roots, but eventually will succumb as they lack the chlorophyll necessary to create the energy for growth and other life processes. One well-known example of this occurrence involves the cacti known as "Moon Cactus" ( actually Gymnocalycium mihanovichii "Rubra' and cultivars). It was noticed that many of these tiny seedlings were very beautiful, occurring in an array of colors including oranges, pinks, yellows, reds, and multicolored combinations. It was discovered that when these tiny seedlings were grafted onto strong plants, such as the epiphyte Hylocereus, that these seedlings not only survived but began to grow quickly and thrive!

Grafting is not a difficult process, but requires excellent sanitation and quick motions to succeed. The materials necessary are two plants, a very sharp utensil such as an exacto knife, isopropyl alcohol, paper towels or clean rag, and some item that will physically unite the two cacti(such as rubber bands), and maintain pressure on the cut portions to enable the fusion of the two cacti. The first consideration is that both plants are in excellent health, with "pumped up" tissues, and are growing actively. The plants should not be old enough that the tissue is lignified (woody). As sanitation is very important, the knife or utensil to be used to make the slices must sterilized, such as by dipping into isopropyl alcohol. The blade should be dipped after each cut, and wiped with a clean rag or paper towel. It is important to work as quickly as possible. Once the cuts have been made, the cut surfaces should be joined together as quickly as possible, to prevent entry of bacteria or fungi and to prevent the open tissue from desiccating. Grafting is usually more successful when done on warm, but not excessively hot or bright days. Some humidity in the air is preferable (to prevent premature drying of the cut surfaces), but it is best not to graft after many days of overcast, humid weather as there may be many fungus spores present in the air.

The actual process entails cutting the plant that will be the "stock" (this is the plant that is securely rooted into a pot, and is the faster-growing of the two plants) with a sharp utensil that can make the slice in one motion as to prevent "sawing back an forth" (which can cause tissue damage to the plant). The tips of the ribs at the cut portion should be trimmed downward ¼" or so, to prevent the center of the "stock" from atrophying away from point of attachment. A very thin slice should be removed from the flat tip. This slice should immediately be replaced over the cut surface, to prevent desiccation of the plant below. The next step is to cut the plant that is to be the "scion" or upper plant. This plant should be cut at the base of the plant. The base should be similarly trimmed, with small upward cuts at the bases of the ribs. At this point, quickly remove the thin slice that is on top of the base, and place the "scion" on top of the other plant, in such a way that the vascular "bundles" are aligned. It is usually only necessary to have a portion of the "scion" aligned with the vascular "bundles"; it is not necessary to have all vascular bundles perfectly aligned. One word of caution at this point; the fluid inside cacti is often very "slimy". Trying to unite these two "slippery devils" and then applying pressure from a rubber band can have very "interesting" consequences. Unless you have some prior experience, it is not unusual to apply the rubber band, sit back to contemplate your deft skills, only to notice that the "scion" is "missing" (sometimes halfway across the room)! For this reason, it is often wise to "practice" on some "extra" plants before trying to graft that "favorite plant". Quickly place the rubber band or other elastic retaining band over the top of the "scion" and secure under the pot. This will gently apply pressure to the two pieces, causing them to “fuse” more readily. Certain alternate methods are sometimes used, such as tape or bands with small weights on either side, but these do not provide the necessary elasticity. Some have even claimed to join the two plants with long cactus spines or super glue, but this is not the recommended procedure. The newly joined graft should be carefully placed warm, shady location for several weeks. Do not "spray" graft with water. A few days after the graft has been joined, it is OK to carefully water the soil only, avoiding splashing on the plant. Constant air circulation will be beneficial to prevent rotting. After a few weeks, if it is apparent that the graft is a success, the rubber band or other retaining band can be carefully removed. If the graft has been a success, the "scion" will have noticeable "plumped" and there should be evidence of shiny new growth at the tip of the "scion". If the graft is not successful, the "scion" will be "rejected" by the "stock" and will usually fall off. If the plant is to be moved, do so very carefully as the fusion is rather tenuous at this point. Continue to water the plant by watering the soil only. After a few more weeks, the graft can be watered normally.

Hybridizing

Hybridizing is a technique that is used to manipulate the genetics of two plants with the goal to imbue the newly created plant with enhanced characteristics, such as larger flowers, increased quantity of flowers, increased number of offsets, or other such improvements. Often, an added bonus when combining the genetics of two individuals with outstanding characteristics includes increased robustness, faster growth or more resistance to certain diseases, insects or viruses. Hybridizers will observe thousands of seedlings, noting various characteristics and will "select" or "hi-grade" those with the most outstanding characteristics. These will be used to produce future plants of a superior quality.

The exciting part of hybridizing is that one never completely knows what might happen. Although on the first level of genetics, it is fairly predictable what characteristics the progeny will have, there can always be surprises, especially when dealing with complex combinations of hybrids cross-pollinated with true species. Many times, a recessive gene from several generations in the past can recombine with a newly created gene, causing an unpredictable and often fascinating characteristic in the new hybrid. 

Lets Build a Cactus Garden

Materials

Large rocks, potting mix

To start your garden look for a sunny, well-drained area. For a lot of us, this will be hard to do. Our yards are too flat, so we have to build raised beds. I like to build my bed so that there will be no chance of the plants becoming water logged. First draw an outline on the ground of the garden. Don't make it to large, you can always expand. Now take out some of the top soil (6" to 12") deep. Then place a narrow strip of plastic where the rocks will be, let it extend into the hole a few inches, this will help control grass from getting in the garden. Now place the rocks around the hole, don't make it round or square, do a natural look. If the garden is to be facing the street you can go two or three rocks high in the back. Now fill the hole to the top of the rocks with your soil mix. A good cactus mix is: one part potting mix, one part washed sand, and one part large (gravel, pumas, broken clay pots,) most anything that will help keep the soil loose. If the garden is to be level, mound up the mix to make it show better and increase drainage.

Now Lets Plant

Take all your plants and set them in the garden to give you an idea as to where to put them. Dig a small hole in the mix just deep enough to cover the roots, leaving the cactus body on top of the soil. Cactus that are not winter hardy can be used by leaving them in the pot. Just bury the pot so they can be removed and taken in for the winter. Give the plants a small amount of water ever two or three weeks until they root. Then let nature pay the water bill. Feed once a year with a plant food like 10-10-10 or good house plant food. Never overfeed, this is where a little does better. A few large well placed rocks will add protection from the hot sun, and help hold moisture, and it just looks good. Now go build that garden and save water.