What is a rice cactus?
The rice cactus (Rhipsalis cereuscula) is a trailing plant with tiny, segmented stems that look a little like grains of rice. Sellers also call it coral cactus or mistletoe cactus. It is a jungle cactus: in nature it grows on trees in Central and South America, in the dappled light below the canopy. That origin explains most of its care. It is not a desert plant, and treating it like a golden barrel cactus is a common reason it declines. For the difference between the two groups, see popular cactus house plants.
Light
Aim for bright, indirect or filtered light, such as near an east-facing window or a short distance back from a brighter one. Strong midday sun can scorch the stems or turn them reddish-yellow, while very dim spots tend to produce weak, sparse growth. Some sellers say it tolerates low light, but it generally grows better with brighter conditions.
Watering (top or bottom)
Water thoroughly, let the excess drain away, and allow the top part of the mix to dry before watering again. Sources vary on how often that is. Some suggest roughly weekly in the growing season, while others suggest letting the soil dry almost completely. The sensible approach is to check the soil rather than follow a calendar. In winter, water a bit less, but do not leave it dry for long: persistently dry soil can make the stems shrivel.
Top or bottom watering both work. Top watering lets you flush the soil, while bottom watering, where the pot sits in a tray of water for a short time, can wet the mix evenly. If you bottom water, remove the pot once the soil is moist and never leave it standing in water, because that invites root rot.
Soil and pots
Use a chunky, fast-draining mix, for example cactus mix combined with perlite and orchid bark. The roots are fine and prone to rot in dense, soggy soil. A pot with drainage holes is essential. Hanging baskets suit the trailing habit; see our roundup of the best trailing indoor plants for companions. Repot only when the plant has outgrown its container, typically every couple of years, in spring.
Temperature and humidity
Normal room temperatures suit it. Avoid cold drafts, and keep it away from heaters and hot vents. It tolerates average household humidity but tends to look better with a bit more, such as in a bright bathroom or kitchen. Misting is optional and does not replace correct watering.
Feeding (and coffee grounds)
Feed lightly in spring and summer with a balanced or cactus fertilizer diluted to half strength, and pause in autumn and winter. Over-fertilizing can damage roots. Coffee grounds are sometimes suggested as a free fertilizer, but there is little reliable evidence that they help cacti, and fresh grounds can compact or grow mold on top of the soil. If you try them, use a very small amount of fully composted grounds. A proper diluted fertilizer is the safer choice.
Pruning and propagation
Snip back overly long or leggy stems to encourage branching, and use clean scissors. Cuttings can be rooted: let the cut end dry for a day or two, then place it on or lightly in a barely moist, free-draining mix in bright, indirect light. Keep the mix only slightly damp until new growth shows.
Common problems
- Shriveled stems: either too dry, or roots damaged by overwatering. Check the roots before adding more water.
- Mushy, dark stems: rot from excess moisture. Cut away the affected parts and repot in fresh mix.
- Yellow or red stems: usually too much direct sun.
- Sparse, leggy growth: probably too little light.
- Pests: mealybugs and scale can appear on cacti. Isolate the plant and treat with a product labeled for houseplants.
Is rice cactus safe for pets?
Rhipsalis are generally listed as non-toxic to cats and dogs, and sellers describe the rice cactus as pet-safe. Even so, eating any plant can cause mild stomach upset, and trailing stems can tempt cats. Keep it out of reach if you can, and call your vet if your pet eats a large amount or seems unwell. If you have a pencil cactus or other Euphorbia nearby, note that those are different and have irritating sap; see is pencil cactus an indoor plant.
A note on Cereus cacti
People sometimes ask about caring for a Cereus cactus indoors. Cereus is an upright desert cactus that needs strong light and a dry rest, so its needs differ from the rice cactus. The upright species can grow several feet tall indoors.