Basic Cactus Care
The following are tips and suggestions for caring for Chihuahuan Desert cacti. Additional information for many species can easily be found online.
Water
The most common question people ask is, “How often should I water my cactus?” That depends on the season, whether your cactus is an indoor or outdoor plant, and the species. Cacti are susceptible to root rot, so it is important to monitor their watering.
How often? Indoor, potted cacti need water every 10-14 days. Your cactus may require more frequent watering in very hot temperatures. Small or young plants may also require more frequent watering.
How much water? Provide enough water so that it runs out of the bottom of the pot. However, never leave a cactus standing in a saucer of leftover water. Cactus roots need to breathe.
Does the water source matter? Avoid using water containing excessive amounts of chemicals, including water from a softener or water containing salts or chlorine. Instead, rainwater and distilled water are good choices for watering cacti. Both are free of harmful chemicals and minerals that can cause soil mineral buildup.
Does my cactus need nutrients? If you water your cactus with distilled water, over time, you may need to add nutrients to supplement the lack of naturally occurring nutrients missing from distilled water. Additionally, fertilizing cacti during the growing season is recommended. Using any good quality fertilizer, mix one-half the strength recommended on the package.
Should I water in winter? If the cactus is in a cool, dry location (50⁰ F), some species require very little or no water. It is normal for some species to shrivel a bit during the dormant period.
Light
Direct, intense sunlight can sunburn and permanently scar your cactus. Additionally, overly bright conditions can cause your cactus to become discolored.
Cacti generally do well in a south-facing window. Plants grow toward their light source (phototropism), so turn or rotate your plant regularly.
Light tolerance varies between species. Some species in the wild grow in grass cover or under another plant called a nurse plant.
Potting/repotting
How often? Repot your cactus once a year or every other year. The fresh soil mixture provides nutrients, better drainage, and an opportunity to inspect the plant for pests. Repot your plant when the plant is dry.
Size? Make sure the new pot has a drain hole at the bottom. The pot should be just large enough to fit the roots and body of the plant. DO NOT use an excessively large pot thinking that you are giving the cactus room to grow. Doing so may cause root rot.
Do I use a potting mixture? Cacti need to be in a loose, well-drained mixture. Use an equal mix of: 1) coarse sand (not beach sand), 2) small gravel, and 3) a medium without perlite, peat, or chunks of bark that would cause the soil to hold water. Add a thin layer of gravel to the bottom of the pot, then add the soil mix, and pot the plant. Top off the pot with a sprinkling of small, coarse gravel, which will help stabilize your plant and prevent soil mix loss when watering. After repotting, do not water your cactus for 5-7 days, allowing any damaged roots to heal.
Pests
Cacti are susceptible to numerous undesirable pests. Two of the most common are mealy bugs and spider mites. Mealy bugs like moisture and spider mites like dry conditions. There are topical treatments and systemic treatments one can use. These treatments usually only kill the adults, so 2-3 treatments may be needed to ensure elimination of the problem.
