OK, you just returned from the store with your first cactus, or perhaps you bought one of those funny-looking little plants with a tag sticking in the pot that says "Assorted Succulents." You might ask yourself, "How do I care for this thing?"
The first thing to realize is that "cacti" and "succulent" are general terms. Cacti belong to a specific family of plants, but the species come from different habitats. Many cacti, such as those in the genus Ferocactus, are true desert dwellers. Others, such as those in the genus Echinopsis, live in the grasslands of South America, those in the genus Oreocereus live in the high Andes mountains, and those in the genus Epiphyllum live in jungles and do not even live in the ground but upon other plants.
When talking about succulents, it gets even crazier. The term "succulent" is entirely non-scientific. It can refer to any plant with fleshy parts (leaves, stems, or roots), usually adapted for storing moisture during drought. These plants come from all over the world and live in different habitats.
Why do you need to know all of this? Well, the more you know about your "Assorted Succulent," the more chance you have of successfully growing it. So, if you are lucky enough to live in an area that has a local cactus and succulent club, visit one of their meetings, bring your plant, and be prepared to find out all kinds of things about it, like what its real name is, where plants of its type grow in the wild, and what growing conditions it likes.
If you are not so lucky to have a local cactus and succulent club close by or are too eager to get started caring for your new baby, all is not lost. Some general rules can be applied to those plants we call cacti and other succulents.
Watering and Fertilizing
Many people think that cacti and succulents require a small amount of water occasionally. While these plants are tough and can usually survive under such circumstances, they most certainly will not thrive.
During their growing season, these plants like regular watering and fertilizing. For most, the period of growth is from spring into fall. However, many plants rest (stop putting on growth) from late fall to early spring, when temperatures are cool, daylight length is short, and during mid-summer, when temperatures are at their peak.
How often to water and fertilize: While growing, cacti and succulents should be watered at least once a week. Some people water more often than this. During each watering, give the soil a good soaking so that water runs out of the pot's drainage holes. A balanced fertilizer, diluted to 1/4 strength during the growing season, can be added to each watering. (A balanced fertilizer has roughly equal proportions of Nitrogen, Phosphorous, and Potassium. For example, a 10-10-10 fertilizer diluted to 1/4 strength is ideal.)
When the weather cools and the length of the day shortens, plants enter a rest period. During that time, increase the interval between watering and let the potting mixture dry out between waterings. Some people say that cacti and succulents should be given just enough water during dormancy to show no sign of shriveling. Use some common sense here. For example, if your plants are kept indoors on a window sill in a heated room during the Winter, they will need more water than over-wintered out-of-doors. In any case, do not fertilize your plants during dormancy.
There are exceptions to the above guidelines, as some cacti, especially some succulents, are winter growers. But, again, your local cacti and succulent club can help you determine your plants' particular growing habits.
A word about water: Tap water often can be alkaline and/or hard, meaning it contains high concentrations of dissolved minerals. Such minerals can build up in the plant's soil over time, causing harm. This is one good reason your plants should periodically be repotted. The buildup of such minerals can also cause unsightly deposits to form, especially on unglazed clay pots. Never water your plants with water that has been through a softening system that uses salt as a recharging agent, as these systems simply replace the hardness in the water with sodium ions.
Rainwater is preferable to tap water if you can manage to collect and store it.
Light
Most cacti and succulents like bright light, but not all can tolerate intense, direct sunlight, especially in conjunction with high temperatures. The intensity of the light that a plant will thrive in depends on the species. A plant grown in optimal light conditions will look normal (unstressed) and is more likely to flower than one grown in sub-optimal lighting conditions. (Keep in mind that succulents, especially cacti, have wildly differing ages at which they will bloom. For example, even if you give your giant Saguaro seedling (Carnegiea gigantea) conditions optimal in every way, you will likely not see it flower in your lifetime.).
While optimal lighting conditions depend on species, some general signs indicate your plant is getting either too much or too little light:
Too much light: When your plant gets too much light, it can appear off-color, taking on a bleached-out look or turning yellow or orangish. Keep in mind that these signs can also indicate other stresses, such as disease or too much water, so use common sense when diagnosing.
If your plant is moved suddenly into very bright sunlight conditions, or if the weather suddenly turns hot with abundant sunshine, your plant can scorch. This can happen rapidly and scar the plant for the rest of its life, so be alert when such a condition occurs and take precautions to prevent scorching.
Too little light: If your plant receives too little light, it might etiolate and/or appear to reach the light source. (Etiolation is the condition where a plant becomes drawn; for example, a normally round cactus begins to look as if it is being stretched out from the growing point at its center). Your plant will suffer if left in such light conditions for very long. When transitioning such a plant to stronger light, keep in mind that it will be especially prone to scorching, so make the transition slowly.
In most cases, it is pretty normal for a plant to grow slowly toward the light. You want to avoid the condition where it reaches for the light. For example, if your columnar cactus is bent toward the window at 90°, it's trying to tell you something.
You can rotate a potted plant's pot to balance its growth toward the light over time. Remember, if you do this, the side of the plant that has not been exposed to direct sunlight for a long time might scorch if you make the transition too quickly. Be careful!
Pots and Potting
Pots come in all kinds of styles and are made of various materials.
Pot materials: The materials most often used for pots are plastic and clay/ceramic (glazed or unglazed). Cacti and succulents can be grown successfully in pots made of either material and choosing one over the other is usually a matter of personal preference.
Plastic pots are lighter, usually cheaper, take up less room than clay or ceramic pots with the same inside dimensions, and are easy to keep clean. Plants kept in plastic pots also require less watering than those kept in unglazed clay pots.
The extra weight of clay and ceramic pots provides stability for tall or top-heavy plants. Many people also feel that a good clay or ceramic pot looks better than a plastic pot. However, remember that if you water with hard water, a buildup of minerals outside unglazed clay pots can cause unsightly deposits to form.
Regardless of the pot's material, it must allow good drainage. It is very difficult, if not impossible, to grow a cactus or succulent successfully in a pot that lacks drainage holes. Therefore, if you find a perfect pot in every respect except for its lack of drainage holes, drill them yourself.
Styles of pots: If you know the species of cacti or other succulents you have, you can better choose what pot style to keep it in. For example, many cacti species have fibrous roots near the soil's surface. Such a plant has no use for a narrow, deep pot; a shallow pot with a relatively large diameter would suit it much better. While appearing quite modest above the soil line, many cacti and succulents have a massive, deep, tuberous root system below the soil and require a pot suited to that root system.
Some people like to use bonsai pots for their plants. These pots are often very attractive; a specimen planted and skillfully staged in such a pot can be a real attention-grabber. However, if you have limited space, be aware that bonsai pots tend to take up a relatively large amount of space, and their price can also be a real attention-grabber.
Soil: Cactus and succulent potting mixes are sometimes available commercially, but many people like to create their own special mix for their plants. There are some basic characteristics that a potting mix for cacti and succulents should possess. Perhaps the most important characteristic is that the soil should drain very well. The best way to achieve this is by adding horticultural-grade sand and grit to the compost component of the soil. Many believe that a good starting ratio for the mix's components is one-third compost, one-third horticultural-grade sand, and one-third grit.
A growing number of hobbyists believe that peat-based compost should not be used for the compost component, as it seems to contribute to pest problems like root mealybug and fungus gnat and does not contribute much in the way of nutrients to the plant. Many people start with a good-grade commercial potting mix for the compost component, and some sift it through a screen to remove such "undesirables" as the small pieces of wood and twigs that can sometimes be found in such mixes.
All sand is not created equal. The sand component should be horticultural grade, relatively coarse, and sharp. Never use non-horticultural grade sand, such as fill sand, as this is usually not washed and can contain salt, among other things.
Most people agree that horticultural pumice is the best for the grit component. However, it is also not widely available and can be expensive if you can find it. Some other materials that can be used include pearlite, porous gravel, and lava fines. People often have good luck using fired clay products for the grit component. These products include certain cat litter and products used to absorb oil spills. Using one of the clay products, you must ensure that it is fired clay that does not break down and turn to mush when wet. Check the labeling, and to be sure, test it out by putting some in a jar of water for some time to see if it breaks down. Mush in your potting mix will do your plants no good.
Like everything else discussed so far, there are no hard and fast rules for potting mixes, so you will need to experiment with ratios. The above ratio of components represents a good starting point.
Repotting: Ideally, your plants should be repotted every year so that you can provide them with fresh soil, inspect and address problems with their root systems, and move them to bigger pots if necessary.
"Every year; yeah, right," you are probably saying. You are not alone in saying that. However, for best health, your plants should be repotted when they tell you they are unhappy in their current "digs." If your plant looks out of proportion with its pot, is pushing its way out of it, has roots growing out through its drainage holes, or is spitting it, guess what?
To repot, invert the pot and gently tap it to loosen the soil and roots from the pot. If the plant is root-bound, you might need to break the pot to get the plant out.
Next, clear away the old soil from the roots. Be careful when doing this, as you want to minimize damage to the roots. A thin stick, such as a chopstick, helps in this regard. Gently tease out the roots and remove the old mix using the stick. This is also a good time to inspect the mix for pests. Any roots that appear dead and dried out can be pruned off. Note that some people use a sharp stream of water from a hose to wash the mix from the roots rather than use the stick method.
Repot the plant into the new pot, which should be larger than the old one and in pleasing proportion with the plant. First, cover the drainage holes with clay pot shards or screening (your pot does have drainage holes, right?), then place the plant in the pot with a fairly dry, fresh mix. You might want to apply a top dressing, such as crushed granite, but this is unnecessary. Now, do not water the plant right away. Instead, allow the plant to rest out of direct sunlight for a week or two before watering it. This allows damaged roots to heal, as unhealed wet roots are susceptible to bacterial or fungal infections.
Old Wife's Tale debunked: Remember your grandmother told you to always add a layer of pebbles to the bottom of a pot when repotting to improve drainage? Your grandma might have made the best cherry cobbler in the world, but forget this advice about pebbles. The potting mix in your pots should extend down to the bottom.
A word about handling your plants: Cacti and succulents grow in extremely hostile environments and have evolved very inventive ways of defending themselves. They will not hesitate to use those defense mechanisms when you attempt to repot or otherwise handle them.
Unless you are tough, you probably wonder how you will get a grip on your spiny cactus while repotting it. Some good "tools" that can be used include newspaper or paper towels that have been wadded or foam blocks.
Beware that not all spines are created equal. Some can be especially nasty. For example, the cacti in the genus Opuntia, commonly referred to as Prickly Pears, have spines that, at the microscopic level, are barbed and very easily break off and remain lodged in the skin. Opuntias also have fine spines called glochids, which, in extreme cases, have gotten into people's eyes and caused problems. Some other cacti, as some Mammillarias, have hooked spines that easily grab fast skin and clothing.
Still, other succulents are known for having poisonous or irritating sap. Plants in the genus Euphorbia are especially known for this. Be careful around them.
Pests
Cacti and succulents are undoubtedly tough plants. However, they are not without their problems. Aphids, snails, slugs, thrips, and nematodes are among the guests who can leave their mark on your collection. Below is a discussion of some of the more common pests of cacti and other succulents.
Mealy Bugs: No discussion of basic cacti and succulent care would be complete without discussing pests, and no discussion of pests would be complete without discussing our little friend, the mealybug. Mealybugs, or mealies as often referred to, are tiny insects about 0.1 inches (3 mm) long, shrouded in an oval-shaped, cottony covering. The presence of these cottony masses, en masse, on your plants signals the fact that mealies have invaded you. Mealybugs live their entire adult lives within their cottony fortresses, happily dining on plant sap. A plant infested with mealybugs will stop growing, weaken, and often eventually succumb to rot.
Their cottony coverings protect them from predators AND contact pesticides. Minor infestations can be handled by dabbing the offending individuals with a cotton swab dipped in rubbing alcohol. The alcohol dissolves the covering, leaving them defenseless. Systemic insecticides are often used to control widespread mealybug attacks.
Being resourceful, mealybugs can also attack the roots of your plants, which are called root mealies. Root mealies might be to blame if you do not see any visible pests on a sickly plant. To eliminate, unpot the plant, and if you find any unwanted guests, wash off as much soil and critters as possible, soak the roots in a systemic insecticide, and repot.
Spider Mites: Spider mites are tiny critters that are all but invisible to the unaided eye. These pests are often found in their whitish webs, usually spun close to the plant's surface. They dine on plant sap. Infected plants frequently develop yellowish spots, which later turn rusty brown, scarring the plant. Weakened plants are susceptible to secondary infections, be they viral, bacterial, or fungal.
Spider mites hate being wet, and of course, so do most cacti and succulents. Overhead watering and misting are often recommended as preventatives and cures for spider mite problems.
Mites are not insects, so insecticides often have little effect on them. However, the use of a miticide is recommended for widespread problems.
Scale: Scales are pinhead-sized insects that appear as raised tan or brown spots resembling marine limpet shells. The shells are hard coverings that protect the insects underneath. Like many other insect pests, they dine on the plant's sap. Outbreaks of scale can be treated similarly to mealybug infestations.
Fungus Gnats: Fungus gnats are often a nuisance rather than a problem. When present, they are tiny black flies that can usually be seen on and around the soil's surface. In some cases, mainly when seedlings are involved, their larvae can cause damage and plant loss. Many hobbyists report that fungus gnats are more common in peat-based soils.
Source: csssj.org
Links
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus