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.