Desert cacti and jungle cacti: two groups with different needs
Most cacti sold as houseplants fall into two broad groups, and mixing up their care is one of the more common reasons they struggle.
- Desert (arid-climate) cacti are the spiny, globe- and column-shaped plants most people picture. They want bright light, a fast-draining mix and long dry spells between waterings.
- Jungle (rainforest) cacti include Christmas, Thanksgiving and Easter cactus, orchid cactus and the rice cactus. They naturally grow in trees in filtered light, so they prefer gentler light, a little more moisture and a more organic mix.
Knowing which group your plant belongs to is the single most useful thing to check before you buy.
Popular desert cacti for indoors
These are widely sold and generally regarded as manageable for beginners, provided they get enough light.
- Golden barrel cactus (Echinocactus grusonii): a round, green cactus with golden spines. Slow growing, and large specimens can eventually get big.
- Bunny ears cactus (Opuntia microdasys): flat, paddle-shaped pads that look soft but carry tiny barbed bristles (glochids) that are hard to see and painful to remove.
- Old lady cactus (Mammillaria hahniana): a small, round cactus covered in fine white hairs, with a ring of pink flowers in spring.
- Other pincushion cacti (Mammillaria): small, clumping and often free-flowering.
- Star or sea urchin cactus (Astrophytum): spineless, with white flecks. Slow growing.
- Chin cactus (Gymnocalycium): small and compact, and often flowers at a young age.
- Hedgehog cactus (Echinocereus): small clumps with showy flowers.
- Column cactus (Cereus): upright and blue-green, and can reach several feet indoors over time.
Popular jungle cacti
- Christmas, Thanksgiving and Easter cactus: flat, segmented, spineless stems and colorful flowers. Our guide to flowering cactus houseplants explains how to encourage blooms.
- Rice cactus (Rhipsalis cereuscula): trailing stems with tiny segments that resemble rice grains. See rice cactus care for details.
- Orchid cactus (Epiphyllum): flat, trailing stems and large, sometimes night-blooming flowers.
Cactus lookalikes
Some plants are sold as cacti but are not. The best-known example is the pencil cactus (Euphorbia tirucalli), a succulent with milky, irritating sap. It is covered in is pencil cactus an indoor plant. Several other Euphorbia species also look cactus-like and share the same sap, so check the plant label.
What should I plant my cactus in?
For desert cacti, use a gritty, fast-draining cactus mix in a pot with drainage holes. Many growers add extra coarse sand, perlite or pumice to a commercial mix. An unglazed terracotta pot helps the soil dry more evenly, though plastic also works if you water carefully.
Choose a pot only slightly larger than the plant. An oversized pot holds moisture for longer and raises the risk of rot. Jungle cacti do better with a mix that holds a little more organic matter, such as cactus mix blended with orchid bark or peat-based potting mix, while still draining quickly.
Light and placement
Desert cacti generally need the brightest spot you have, such as a south or west-facing window with several hours of direct sun. If a cactus becomes pale, thin or stretched toward the light, it probably needs more. A grow light can help in dim homes. Jungle cacti prefer bright, filtered light and can scorch in strong direct sun.
How often should you water a cactus?
There is no fixed schedule, because pot size, light, temperature and soil all change how fast the mix dries. A reasonable approach for desert cacti is to water thoroughly, let the water drain, and wait until the soil is completely dry before watering again. In winter, when many desert cacti are resting, water far less. Jungle cacti should not dry out completely for long periods during the growing season. Pressing a finger or a wooden skewer into the mix is more reliable than a calendar.
How long do house cacti live?
Lifespan varies widely by species and conditions. Many cacti are slow growing and can live for many years, sometimes decades, when well cared for, but a figure for “the average house cactus” would be a guess. Overwatering and low light shorten the life of most indoor cacti.
Pet and child safety
Treat every cactus as a potential injury risk. Spines can puncture skin, and the fine barbed bristles of prickly pears can embed easily and are hard to see. Keep spiny cacti out of reach of young children, cats and dogs, and be especially careful with plants on low shelves or the floor.
Plants with irritating sap, such as pencil cactus and other Euphorbia, are a different concern. The milky sap can irritate skin and eyes and may be harmful if swallowed, so they are best kept away from children and pets or avoided altogether. Jungle cacti such as Christmas cactus and rice cactus are generally listed as non-toxic to pets, but eating any plant can upset a stomach. If a pet or child chews on any plant, contact a vet, poison control service or doctor for advice rather than waiting.
Common mistakes
- Watering on a schedule instead of checking whether the soil is dry.
- Using regular potting soil without added grit.
- Keeping desert cacti in low light.
- Treating jungle cacti like desert cacti, or the reverse.
- Moving a cactus from indoors into full sun without a gradual adjustment, which can cause sunburn.
Choosing a first cactus
If you have a very sunny window, a golden barrel, pincushion or chin cactus is a sensible start. If your light is more modest, a jungle type such as Christmas cactus or rice cactus is often easier, and other succulents that suit indoor life are worth considering too. In a home with pets or small children, a jungle cactus is usually the lower-risk choice, and the benefits are summarized in indoor cactus benefits.