Growing Cactus with Artificial Light

Lighting plants is actually very simple, despite the acres nonsense written about it on the internet. Work out how much light you need for area amount of plants you find a lamp that effectively provides that the amount of light, and find a way to shine all the plants.

Yet growing cacti in artificial lighting is not easy and can be very rewarding. OK, maybe you could say it is easy, but you will need to make some $ 100 to spend on a kit and expect inquiries from the police the power company tells them how much juice you start to use.

Most cacti need very intense light, approaching the intensity of the sun. Ideally a lot of them will be even more intense light than direct sunlight in Britain prefer. This light intensity can be achieved only with HID lighting, expected to need relief 100W per square foot plant. In practice, you can be pretty results with half or get a quarter of the, because the light on all that day and every day intensity can be maintained. Make sure you do more natural light than you adding block!

Direct sunlight during the middle of the day in summer is 5-10 times more intense than you would achieve with most plant lights. Even the summer shade is as bright as most artificial light systems. So use natural light as you have. The main problem is that the back of the plants in a window never gets enough light and they can lean or stretch.

Unlike the cost to put the heat on the requisite level of relief for cacti can be a big problem and you will need to have a pretty strong system of both the fans to stop overheating the plants and the rest of your home overheat stop running.

You'd better be looking for types of cactus or other succulent plants that will grow well in your western window or outdoors without much sun. The "forest" cacti, epiphytic cacti generally, and some manage Caribbean or South American species at lower levels light. Small globulars, Gymnocalyciums, Fraileas, some Mammillarias, in fact many of the things you can find in bubble packs at B & Q, is tolerant of less than ideal circumstances. Or maybe you can get to keep Haworthias, Gasterias or other succulents that burning sun needs the day.

Light Requirements

You can have too much artificial light, but you have a couple going to do it!

The amount of light needed for the growth of a desert cactus full-time upward of 2,000 lumens per square foot. As a rough rule, accept 20W per square foot as a starting point, 30W is better. Small tubes as two feet 20W compact fluorescent and children, are less effective, you will have a minimum of 30W per square foot required, but I do not recommend. For comparison, direct afternoon sun is 10,000 lumens per square foot or more, but it is lower in the early morning and late afternoon and under cloudy. You can somewhat compensate by running the lights at full power for 14 or 16 hours a day, but the plants will not develop the same spination will not grow as compact and difficult to flower, but would definitely stay for a time as over the winter. For full-time growing cacti of full sun, you can use up to 100W per square foot.

For small areas, the spiral compact fluorescent can be used, but you will need about 50% more power, because they are not very efficient. For medium to large areas, straight lamps are good, but do not use very short children unless you absolutely have no choice. You probably do not metal halides for cactus seedlings, unless you have a whole room full, but they are good for large parts of the adult cacti. I would not recommend HPS again unless you have a whole room full, and also because cacti among them etiolate unless you fill light. Do incandescent or halogen lights, too much heat, not enough light use. LEDs are now an option, but difficult for a beginner to know what is needed and whether it is sufficient.

The heat thing is a bit of a red herring, of course, a 400W bulb gives more heat than a 150W lamp. How a 15W lamp, even less heat, but you can work out for yourself why you would not use it. Choose the lamp that gives you enough light, anything bigger just wasting money (and before you arrive to the A / C!), And then work out if you need fans to cool it.

These figures assume that you most of the light on the plants with a good reflector and side screens, or with a light used in a fine white-growing region. Most standard reflectors would probably wasting half the light.

You may be able to use a lower light levels if you have a pair of natural light, as you grow jungle cacti, to raise seedlings, or for overwintering. I use almost 2,000 lumens per square foot of 5x36W T8 fluorescent for some overwintering winter growing succulent, 1-2 years seedlings, and anything that likes to be really hot. I run this light for 10-12 hours per day, because some of the plants are sensitive to day length and only bloom in winter or after winter. I use 600 to 1.200 lumens per square foot of two CFLs for the start of cactus seeds.

Light intensity

Intensity is simply the amount of light falling on a specific area. You really work hard use of artificial light to get the same intensity as direct sunlight. Even if you can do it, the light is usually lower in UV. But you can see the full intensity of the light that you can not always get to meet the sun. Still difficult to provide enough light for an adult cactus.

Penetration is a very abused term, but let's just stick with plant lights! Very few people understand that penetration means, they just programmed to think that powerful light somehow magically a good penetration and reach the bottom of the plant. Penetration is actually a function of the collimation of light, which we already talked about. Sources of light that spreads quickly from poor penetration, the light intensity at the bottom of the plant is much lower than at the top. That is why the placement of a plant close to a poorly designed light is not a good substitute for stopping to spread the light. Powerful light sources are generally placed far away from the plants so that there is little difference in light intensity between the top and bottom of the plant. Hence the "myth" that powerful light sources has better penetration than poor children. The sun is the best example, a very strong light source placed so far away that there is essentially no difference between the light intensity at the bottom of a plant and the top. A powerful light source placed near the plants have a very weak penetration, the bottom leaves will die from lack of light and the top ones will scorched by too much light.

Distribution of light

Fluorescent, and all other lights for that matter, do not lose effectiveness with the distance, the light just spread. Avoid the light of the spread out and you can plant as far as you want. Of course, no system for that or focus, the light be 100% effective so that the attachment of lights on one side of your basement and plants around the corner on the other hand will probably poor results! Remember, shop light "reflectors" designed to spread the light throughout the room, not to put it all on a seed or plant tray, hence they are useless for what we need. Likewise, get rid of any diffuser on your lamp.

After all, why would you have a light fitting designed to distribute light evenly over taking a 400 square foot room and use it in two square feet of plants? Use a light system designed to focus light on a small area and all the preconceptions about inverse square law and lose efficiency light to go out the window. Lasers intensity lost distance, search lights lose intensity distance, why should you settle for a plant light intensity lost the distance? Or where three-quarters of the light mist the plants altogether?

The simplistic solution of placing candles almost in contact with plants is just about the worst possible approach. You will still end up with half or more of the light hitting the plants, only useful if you need a very brightly lit basement for 16 hours a day. Also, the difference in light intensity between a quarter inch from the tube and said two inches at the bottom of the plant will be large, resulting in poor growth. The whole arrangement is completely useless when the plants are more than a few inches long.

There's nothing magic about it. Plant lights produce a certain amount of light, and as long as light escape or get absorbed then it plants no matter how far they are achieved. In practice, each reflect an area lost about 20% of the light, that you do not want to go far feet, but there is certainly no need to push everything to the ducts. Whatever you end up with, it is important to get all the light on the plants instead of just turning your basement into an artificial beach. Use a good reflector, the people who come with fluorescent lights designed to light spread across a whole room, it does not focus on a few square feet. Around the lights and plants with many white surfaces as possible: white shelf above and below; white wall behind it; even hang white card or Mylar to the front of the shelf for most of the time.

Ultimately, no one can tell how close to the light, so that depends entirely on the design of your reflector. When the plants start to burn, increase the light. Try to light at least as far away from the plants and the height of the plants. With an open shelf, try to arrange the plants so that they all have the same distance from the light. Or surround at least three sides by white sheeting and then it will not matter.

Distance of the light is irrelevant. What is important is how much of the light makes it to the plants rather than out the window lighting the rest of your basement. The lights near the plants is just the simplest (and worst!) Way to a great deal of light on a small area of ​​plants. Very high intensity lights should away from the plants are placed to prevent overheating and ensure that the light from spreading to a meaningful intensity.

A "cage" is a good solution for getting almost all the lights on the plants without loss. If you are using a shell, just paint it white instead of going through the pain of the use of Mylar. The latex paint they used to make your roof reflects sunlight is probably the best, but ordinary interior flat emulsion paint is almost as good. The problem with camps for the growth of mature cacti that moisture trapped and humidity rise. Heat buildup will be a problem if you use enough light for an adult cactus, so designing a extractor fan in your house. Displays included work well for seedlings, they want constant moderate light, high humidity, and heat resistant.

Light Duration

Cacti not react strongly to photoperiod, but many of them do set their flower through a cool, dry winter. Put them on a timer on during normal daylight, because many succulents need to know when his winter. Mesembs is very seasonal and it is caused by the length of the darkness at night.

For seedlings, I started with 20 hours of light and bring it slowly to 16 hours after germination. Tall'n'skinny seedlings caused by low light intensity and warm temperatures. Night temperatures are the most important, get them as low as possible (without testing their hardiness) as soon as the seedlings emerge.

Increasing the number of daylight hours of a light bright enough not to aggravate etiolation. Cacti grow faster with more hours of light and more hours of warmth, but they will only remain compact if you increase the light intensity or the temperatures drop. For best growth, keep seedlings warm day (75F-85F for most) and cool at night (55F-65F for most) and give them the light just enough to keep them, but make them compact red to . If you give them too much light will they turn colors and not as fast growth, even die if you really love. You can boost small seedlings along nicely with constant heat and long hours of moderate light, but ultimately you have more mature conditions or you might as well buy the fat plants from Home Depot. You can use lights for fewer hours if you want to use a higher intensity, but most of seedlings cacti will stop growing as the light becomes too intense.

The light spectrum

As for picking the "right" wavelength of light to grow plants "best", it is a bit like trying to pick the right vitamin for people to live. You can not do it, they are all important for different things. Specific wavelengths, or more important specific pigments activated by light at a specific wavelength, showed that the orientation of leaves and flowers plant relative to the sun to control the orientation of chloroplasts in leaves, chlorophyll amount generated within leaves, the size of the leaves, the opening and closing of stomata, the opening and closing of flowers, and the incorporation of flowering and fruiting. Mostly these wavelengths toward the blue and green end of the spectrum, the red end this sugar makes mostly chlorophyll.

Plant light sellers make a big deal out of the chlorophyll absorption spectrum and the green light is useless. There are many pigments in plants, not only chlorophyll, and plants can use the light to any color. Deep red light is the most effective in terms of a simple photosynthesis, but not to a large extent usually claim, and plants grown just get red light leggy and too fat. The first step is a little blue light, the plants do better to add. Some people would claim that plants can be healthy without light that closely resemble full spectrum sunlight, others monochromatic red light blows everything out of the water. I do not see huge differences between them and go to extremes in either direction has great disadvantages.

UV "tension" plants and not much else. There certainly could grow no biological need for it and plants without it. In the case of cacti, show the plant can be desirable, it produces heavy and dense spination, skin color, and "stunts" plants so that they flatter. Shorter wavelengths of light in general produce plants with shorter limbs, smaller leaves, and more branching. It's not quite as simple as the primary controller Internode length, the relative levels of red and far red (and near infrared) light. This is one of the reasons that bulbs and HPS lights can produce serious etiolation. This particular combination of light wavelengths are generally ignored in the whole blue / red debate, partly because it is difficult to identify the relevant wavelengths and partly because it is still difficult to see control them.

Anecdotally, will not flower without the high levels of UV few cacti. The high-altitude Andean dwarf Opuntioids a group, but potentially other mountain species such as Pediocactus will not do well without UV. This is particularly relevant for plants that pretty much spent their entire lives behind a piece of glass or plastic blocks virtually all UV. It is hard to separate the effects of UV from sun up to date with only a very high light intensity. As you will see from reading the lizard pages, it is difficult to imagine anything outside UV levels get light. I do not worry too much since my plants sun in summer.

Types of lighting

Light, as much as you can get. T for a small area, or metal halides if you want a whole room light.

-Incandescents

Not good, too hot, not enough light. There are some metabolic effects were short-wavelength infrared light increases the rate of photosynthesis and some producers have tried to cheat the laws of physics by adding bulb to their other light work better. Unfortunately, in almost all cases the bulbs are so inefficient better results easily be obtained by using more or better regular plant lights.

Fluorescent Tubes

Good for low to moderate relief of small to medium sized growing areas, and can be stretched to higher intensities and larger areas.

Four 36W or two 58inch tubes you will have a good even spread over about 10 square feet gives (in a standard commercial fit, but you can smaller as you build your own making), which is good for starting seeds or overwintering . I guess the light intensity is not high enough for a successful year by growing high-light plants. You can get by, but I do not think you ever really satisfied with the results. Consider high output T5 fluorescent if you want all year round to grow, they will almost twice to give light in the same space.

I'm not keen on the tiny two-foot fluorescent. It costs almost as much as four feet children, sometimes more, but they are less effective and therefore less capable of producing sufficient intense light. Fluorescent can just about producing the light intensities you need for mature cacti so you really need to use the best available. So much I prefer to arrange my plants in a form that can alleviate by four foot tubes.

Compact fluorescent (CFL)

Compact fluorescent is just a liquidated fluorescent tube. Quite a lot of light from such a small area, but usually not very powerful as only good for a small number of plants.

A compact fluorescent is always less effective (less bright) than a similar straight tube of the same power. In the case of the "Envirolite" type CFL the difference is dramatic, they are comparable in efficiency and life to the small household energy saving CFLs. Good straight tubes is about 50% more efficient.

Although a compact fluorescent less efficient than a straight tube of the same power, it is sometimes more effective than a straight tube of the same length for short lamps are inefficient. A compact fluorescent is a long tube that just lost a little, because it is bent. Compact fluorescent tubes are thinner, usually T4 or even thinner, and this generally better than fatter tubes. Compact fluorescent output very quickly, much worse than the best straight tubes, worse than the best modern metal halides and HPS lost.

The 55W power compact (basically a four-foot tube bent in half) make a good comparison with the four-foot 54w T5HO tube. The compact power is half the length of the straight tube, give 25% less light, and lasts half as long. Two straight two-foot T5HO tubes export almost identical to the 55W power compact, 15% lower power, 10% less light, but a dramatically longer life, but they would take a wider space. A 55W multi-bend compact fluorescent less than a foot long, barely produces half the light of the straight tube, takes half as long to failure, but lost so much output that you should throw away (like a plant light) to 1,000- 2,000 hours. Note that the standard output (HO no, not overdriven) T5 tubes is even more effective, but the low light intensity compared to T5HO tubes means that they are generally not used for plant lights.

The Envirolite type CFL just awful performance. The only reason to use it for a quick and dirty solution to a few hundred hours where low startup costs outweigh the poor performance. Compact fluorescent useful for very small spaces, but if you want to 125W and 250W light certainly there is always a better solution.

HID (High-Intensity Discharge) lighting

HID lamps are just not worth messing with at low powers, inefficient, poor life, warm, and generally not worth it. Normally I would suggest you just HID lights use about 250W upwards 400W ideal for their high efficiency and ability to provide high light intensity of a good size area. Smaller lights produce less light, lost output quickly, shorter life, and does not cover a large enough area. They can be used for high intensity lighting on a small number of plants, for example, 150W will be well to maybe five square feet be. That said, I would normally something like a 4 x 54w T5 fluorescent system for someone looking for 150W HID bulbs ordered.

Metal Halide lighting

Metal halides have been the default choice for growing high light plants, but the choice should be more automatic. High performance fluorescent and T5HO as the latest VHO tubes offer competitive performance and some benefits. Few people will provide an unbiased comparison because they try a product or to sell others. Metal halides offer a small extremely intense light source with high efficiency, but lumen maintenance, lifetime, and cost can not compete with the best t. A good 125W pulse start metal halide will have similar efficacy high intensity fluorescent lighting in a much smaller package offer, but will lose 30% of the proceeds in the first 5000 hours, so there will be an urgent need for small size or extreme light intensity this worth making. Usually you should stick to the effective and widely available 400W metal halides which are more convenient than fluorescent lighting for large areas and for providing high light intensity.

Watch out for those metal halide bulbs, they will get out a lot less light after using it for six months. Historically, plant growers metal halide bulbs replaced every 6-12 months, although they run for a few years. For a variety of reasons, the plant is light sellers often still wedded to an outdated technology known as probe begins. Modern halide lighting pulse start them longer, they do not lose light as they age, they start faster, and they are less likely to explode, but they have a different ballast needed. Pulse start ballasts and bulbs are generally more expensive, but plant lighting is often sold at a huge markup anyway, and you should be able to find a pulse start ballast and bulb for less than $ 170. You will usually find them sold as business and warehouse lighting. Another worthwhile improvement efficiency is get an electronic ballast (often known as a digital ballast by plant vendors although light strand that is not quite the same thing), they will save about 10% on your electricity bill.

Another very confusing issued many abused by those who try to sell something is heat. You will get the same amount of heat 400W lamps as you do from a 400W metal halide. You can see it in different places, but do not be fooled by the fact that one is a small raging hot bulb and the other is many meters of moderately hot glass. Still, metal halides in a house several disadvantages including fire hazard and fade nearby materials. And of course, if you do not need 400W of light then there is no point wasting all that power and get way more heat than necessary. Metal halide lamps radiate more heat than infrared (UV and also) as t that good in a mature cactus can be, but can be hard for seedlings.

HPS (High pressure sodium) Lighting

HPS lamps would not only be a good choice for the growth of most succulents. They tend to etiolate and grow dense spikes or develop a good color. Use metal halides or a mixture, unless you just supplement natural light.

HPS is waaaayyyy better efficiency than flourescents or metal halide in terms of lumen output but in a limited range which is not always suitable on its own, certainly not for most cacti although I'd bet that Pereskiopsis would just love it. Metal Halide retailers like to compare their products in PAR watts where they can exceed HPS lamps, albeit slightly misleading. When properly measured as a photon flux the HPS is even better.

HPS technology has not advanced as much as metal halide in recent years and the gap is narrower than it once was. Digital ballasts are available, but the basic lamp technology has not really moved on. HPS bulbs always offered better life and better lumen maintenance than metal halide but they did not so much as the difference is now much less improve. HPS lamps to achieve peak performance entirely until the 600W-1000W series although 400W bulbs are pretty good. There are an increasing number of crossover HED light spectrums offers a combination of HPS and MH, or with swappable HPS and MH bulbs in the same pace, but you always pay a price for the flexibility.

Led (Light Emitting Diode) lighting

Very many experiments documented using LED grow lights. Performance in terms of the plant mass and size are comparable to other light sources in the same light intensity, although it can be very difficult to determine the true intensity of a non-white light source. The typical "red plus a small blue" LED light usually produce different growth patterns, mainly less compact and less branched plants. Note that this is in stark contrast to the claims made by LED light plant sellers want you believe that three LEDs completing a battery is equivalent to a 1000W metal halide lamp.

I look at LEDs every year or two, but so far I have not tried on plants. Until recently, they are simply not strong enough or effective enough in the manufacture of light (compared to the best conventional solutions) to make them more than to make a toy. Now they are available at performance levels that are potentially useful, but the initial cost is still high, very high for commercial LED plant lights. I should probably try a little DIY LED setup but it is not going to happen this winter. By the next year of the course they have 50% will be better!

The specific wavelengths of LEDs are often used as a great advantage and used to justify how a massively under-powered lights can perform like its bigger brothers. It is 90% marketing hype; LEDs happen to provide light on only a single wavelength so make it a point of sale. In practice, the lamps available for decades providing virtually the same spectrum. The earliest called Gro-Lux and they massively better than plain white light sources were not, and with a significant disadvantages in terms of efficiency and operating life. Today you can still similar light selling Google for "press". Gro-Lux t is still available, but they now have a wider distribution of the light, still mainly blue and red, but other wavelengths as well. Experiments have shown variable results of just using monochromatic blue and red light vs. white light, sometimes a little more, sometimes a little worse, but do not expect the spectrum of the laws of physics change for you. The monochromatic light output, especially in the far red and blue wavelengths is very difficult to compare with a white light sources. They will look relatively weak because our eyes do not see those wavelengths and for the same reason the output in lumens are not directly comparable (although it can be transformed if you know the wavelength), but few manufacturers will collect accurate photon output of their lights. They will often give you the total light output in any units. Buyer beware!

LED produce such strong directional light, without any need for additional reflectors, which penetration is actually quite good. You will have to check your specific LED as some produce a much wider spread of light than others. Many LEDs produce almost their their light in a 10 degree cone, much better than what you will achieve even a very good conventional reflector. An LED with a 45 degree light cone would not be as good and you will be very close to sit or use additional reflectors. The large arrays to be used with LEDs naturally produce very good directional light with good penetration. Even if the LEDs on the edge of the settlement sends a little light away from the plants, the vast majority in the middle of the arrays is hitting plants even with their off-center light. This feature is often used to provide misleading comparisons, where a very powerful conventional produce light similar growth to a small LED light, just because 90% of the conventional light hits the plants.

There are a few other interesting points about LEDs. The long lifetime is often cited as an advantage. Typically a life of 50,000 to 100,000 hours will quoted although some of the newer high power LEDs shorter lives. What is not highlighted that the light output of an LED decreases more or less steadily from day one until it dim to see. You must look and see what the actual lumen depreciation because it unusable as a plant came to light after 10,000 can be - 20,000 hours. This is of course a couple of years and then LEDs less than a dollar will cost and brighter than the sun. The best lamps lose 5% of the proceeds on a 20,000-30,000 hour lifespan, modern HID lamps 10% -20%. LEDs do not really beat in this regard.

High power LED arrays must be carefully designed. Cool operation is often an advantage, but LEDs actually produce a similar amount of heat to other plant lights. The difference is where the heat is. In a metal halide lamp has a very high percentage is radiated away, that bad for plants that can get close, but at least stop the bulb melts! LEDs emit relatively little heat away, they just dump it in the semiconductor and will deteriorate quickly without careful cool design. It's hard to tell by looking, but cheap LED lights will probably long before that failure 50,000 hours.

I have not seen buy LEDs that same lumen (or photon) output per watt than modern metal halides or t have. Maybe they exist or perhaps not, the only people I've seen in laboratories or special order at a special price. Again, the people selling the LEDs would say they are more efficient than other light sources, but they also like to use what is essentially obsolete technology for their comparisons. They also "test" with a poor quality conventional lighting run the majority of the light never even land on the plants. Under such circumstances, LED blow away conventional lighting at the same levels, but they do not when you compare best practice setups for both types of light.

The top LEDs available in the UK far exceeded incandescents (although they still can not match the total output of a small area like a normal bulb), slightly better than compact fluorescent drew mainstream triphosphor T8s electronic ballasts, has a way short of the best T5 and T8 tubes and similar up-to-date (pulse start, ceramics, digital ballast, etc.) metal halide lighting, and way short of HPS lights (which have their own disadvantages). I see reliable data of white light LED about 70 lumens / W, with monochromatic LEDs a little better, although you can not measure in lumens / W I expect 90-100 lumens / W of my plant lights and I expect LEDs that level will very soon (written in 2009) to reach.

Other Specialist Lights

I tried the specialist t like the aquarium avoid light. They "interesting" spectra but they can incredibly inefficient and should be replaced every few months. Aquarium people have a very strict requirements for color, UV levels, a difficult task lighting things through some deep water, and very limited in it all under a small canopy. They really took to the new technology as overdriven T5 fluorescent and compact power which is a very light suit in a small area. When I grew up my whole cacti year under lights I would probably try adding more UV and I certainly want more light intensity, but for planting. My current lights that I moderate light levels of about 2,000 foot candles will not mention, but the plants look good winter and some of them even flower.

An increasingly common type of plant is called light blue fluorescent. This shows the modern triphosphor tubes, usually T5, with some or all of the green phosphor missing be. Performance is good, with lumen maintenance and lifetime comparable to other quality tube lights. They could even better than a standard white source perform because of their spectrum, but it is worth remembering that the red light by the red triphosphor is nowhere near the record high of chlorophyll, so most of the ads claims are clearly bogus.

Special Considerations for seedlings

Cactus seedlings are easy to start under artificial light. Surprisingly, most of them can the sun when they take small, so you do not have to shadow them or grow them under lights. They also most of them anyway, like a high humidity and regular watering for the first few months.

I use two spiral compact fluorescent for starting seeds 20W each for germination to 30W each for growth. This distributor is 2.5 square feet. I run the lights for 16 hours a day on a timer.

You can start seeds cactus under just about any fluorescent light. Get that is convenient for you to find and easy. Ywo 36W T5s would have enough light for an awful lot of seeds, up to 10 square feet, though perhaps half that for the growth in the first month or two.

You can also sow in natural light if you have a good clear area in direct sun. However, you may still want to light the winter, because seeds sown in the autumn are still very small in their first winter.

The standard hot / soft white or cool white fluorescent what you will find in any box store is good for starting seeds, but if you grow the seedlings for many months as from fall to next spring, you may want to look for or 5000K 6500K tubes will give you healthier seedlings. You can do it either way, but I think you'll seedlings under say a 3500K light grown for almost a year will get a bit inflated or long to find. Do not worry about the advice of your grandfather (or cactus club president!) Give to mix warm white and cool white lamps. It has a useful effect with older designs, but modern triphosphors it is useless. Choose the shade of white you want and use it.

The "baggie method" is well suited for use in a distributor with artificial light. Sealed in plastic pots can be hot in the sun to get that it may be difficult in natural light.

How much light? For cactus seedlings would 15W per square foot over right, it is about 100W / sq m. For small seedlings germination and not having a good thorns, half of this amount may be enough. Properly growing mature cacti and some types of seedling, twice as much or more is needed. These figures apply only to the common forms of plant lighting, lamps and metal halide and match a little more than 1,000 foot candles or lux 10,000. Other types of lighting can produce different levels of light per watt, or even a range that is not properly represented in lumens. Properly growing mature cacti and some types of seedling, twice as much or more a minimum and more is better.

Finally, and most people fall here, get all the light on your plants. If you can see the bulb / tube then the light shines in your eyes and not on the grass. Using a reflector that almost completely encircles the globe and focus the light from just the plants. Better yet, join the whole thing, plants and light, in a white or reflective casing properly. Cactus plants not care included, but check the temperature in the case is also included and warm. I use a small extractor fan, actually a PC case fan, but relatively small openings in the top of the cage will be enough for warm air rises from. Also, after the first few months, try the night temperature drops late 20F or more. Constant hot nights and only moderate light levels will produce rapid growth, but the seedlings will etiolate.

You can almost any cactus seedlings in a somewhat enclosed lightbox hold for a year or more if you really wanted. Generally they quickly without extremes and tension of the natural conditions grow, but eventually you will probably want to expose them to the sun, high and low temperatures, and some water stress so they do not grow in a large green with beachballs no thorns For some species such as Strombocactus, a good year or two under the lights with high humidity is almost the only way to stay alive. Others, for example many Opuntias and Echinocereus, is so strong that you generally they just stick in the sun and treat them as an adult after a few months.