CACTI are some of the most rewarding house plants, as long as you have adequate light. Few flowers can compare in color, size or beauty. Most cacti grow slowly, so space is usually not a problem. They are very tough and adaptable. Contrary to popular belief, they do not “thrive on neglect”. Like most plants, they “thrive” on tender loving care, but they will at least “survive” on neglect.
The general care information below is for cacti and most other succulent plants. *Exceptions include epiphytic (tree-dwelling) cacti and succulents—Christmas cactus, rhipsalis, orchid cacti, etc.—which prefer less sunlight, more humidity, and more watering than other species. They also appreciate a higher percentage of nitrogen in their fertilizer. Add less sand to your potting mix than for other species. Haworthias and some other succulents also prefer bright indirect light to direct sun.
Indoors, give cacti and other succulents the brightest or sunniest window you can provide (four to six hours of direct sun). In less light, they will become long and skinny, an abnormal growth habit. We highly recommend summering your plants outdoors in morning or late afternoon sun, where increased air circulation and light will benefit them immeasurably. Most succulents can endure full outdoor sun, but must be acclimated to it. When placing plants outside, first set them in partial shade or shade, gradually introducing them to the strong late spring and summer sun over a couple of weeks.
Wooly and heavily spiny species require the most sun, while spineless species normally require midday shade. A reddish discoloration may indicate that your plant is at or beyond the intensity of sun it can tolerate.
When you water, water thoroughly, and allow the soil to dry before watering again. Succulents are especially prone to rot as a result of over-watering. NEVER water your plant if the soil is already moist. Dry pots are lighter than wet ones. Clay pots feel cool and damp to the touch when soil is moist within them. Succulent leaves are firm and plump when the plant has enough moisture in the soil.
Most cacti and certain other succulents prefer to remain considerably drier in the cooler seasons of the year (usually October through April). Water less frequently than normal during this period. In the spring, you may mist your plants early in the morning on warm days, to stimulate new growth. Plants will absorb moisture through their spines. We also recommend watering plants from the bottom of the pot during early spring, so that new roots may develop free from the suffocating effect of overly wet soil. Fill the plant’s saucer with water, and allow about 30 minutes for soil, pot and plant to draw up moisture, then discard the excess water.
If your plants are in clay pots, they will achieve maximum potential if you embed them in a mixture of 50% peat and 50% coarse builder’s sand. This prevents rapid drying of the soil, and allows the roots to develop in the even moisture created by the peat/sand mixture. Be sure the tray holding the peat/sand mix has good drainage.
In winter, keep cacti and succulents above freezing. Some plants prefer a nighttime temperature of 35-40ºF (some cacti and other succulents can endure temperatures well below freezing if kept absolutely dry.) More tropical succulents like adeniums, euphorbias, lithops, and stapeliads prefer a minimum of 50-60 degrees.
In summer, plants should be protected from extreme heat, as their root systems are more vulnerable to damage in a pot. When humid and hot, good air circulation and careful watering will avoid fungal and rot problems.
Feed your plants once a month from May to September with a low nitrogen (less than 10%) formula fertilizer such as 5-10-5 or 10-30-20. Too much nitrogen encourages excessive rapid green, but weak growth. Always dilute the fertilizer more than the label instructions advise, as most cacti have adapted to growing in nutrient-poor soils.
Repot in the spring or early summer. Most species appreciate annual repotting when young, only increasing one pot size. Once you reach about a 6” pot size, you may carefully remove the top inch or two of soil, and replenish this with fresh mix, without moving the plant to a larger pot. Succulents tend to be heavy plants, especially potted in clay, and become difficult to handle when moved to larger and larger containers.
Avoid soils with a high percentage of peat moss. Peat holds water too long, and will not moisten easily once allowed to dry completely (a frequent occurrence with most succulents). A small amount of peat can be used to improve soil texture, and you may add coarse builder’s sand to the soil to increase drainage. Lithops (living stones), wooly cacti and stapeliads appreciate as much as 40% sand. A top dressing of fine gravel around the base of the plant is advisable as it promotes better absorption of water into the soil, protects the plant base from excessive moisture, and is esthetically pleasing as well. If possible, add a tablespoon of bone meal and gypsum for every 3
inches of pot size.
For heavily spiny plants, use a pair of wooden tongs or a rolled up piece of newspaper to grasp the plant and ease it out of its pot. If stubborn, do not force the plant out, as you will damage the root system. Tap the pot against a hard surface and try again. Remove as much soil as possible without damaging the root ball. Always repot the plant at or above the previous soil level, to discourage rot. You may need to stake columnar species. Wait a week or two after repotting before watering to allow new root hairs to develop.