How to grow and care for a fishbone cactus

Where to grow fishbone cactus

An understorey plant adapted to tropical conditions, fishbone cactus thrives in heat, humidity and bright but indirect light. Grow fishbone cactus in a warm room, with winter temperatures no lower than 15ºC, near a north- or west-facing window. A bathroom or kitchen usually provides sufficient moisture, but in drier rooms you can mist the leaves regularly or use a humidifier set at 60 per cent humidity.

How to plant fishbone cactus

Fishbone cactus is an epiphyte in its natural environment, so absorbs nutrients and water from the surrounding atmosphere. It therefore thrives in well-drained but humus-rich soil. For best results mix perlite and orchid bark into peat-free cactus compost, and pot it up as you would any other house plant. Water well but always allow any excess water to fully drain from the pot.

How to care for fishbone cactus

Unlike desert cacti, fishbone cactus needs watering regularly, ideally when the top couple of centimetres of the compost are dry. Fertilise once a year in spring, with a liquid cactus fertiliser. There's no need to prune fishbone cactus but you may want to remove dead or dying leaves to improve its look.

Bear in mind that aerial roots may appear in the surface of the soil. These are normal – in the wild, these help the plant anchor itself to tree branches and absorb water and nutrients.

How to get a fishbone cactus to flower

Given the right conditions, fishbone cactus will sometimes bear flowers. These are true cactus flowers: opening at night as a mass of cream-white spiky petals with an intense fragrance. For the best chance of success, your fishbone cactus needs to be exposed to cold temperatures in winter to early spring — ideally between 11-14ºC. With luck, your fishbone cactus should flower in late summer.

How to propagate fishbone cactus

Fishbone cactus is easily propagated from stem cuttings. Use sharp scissors or secateurs to remove a stem around 10cm long, and set it to one side in a cool, dry spot for a day so the cut can callous over. Then plant the cutting into a small pot of peat-free cactus compost and water gently, allowing excess water to drain from the pot. Keep the pot in a bright spot and keep the compost moist. You should see signs of growth within a couple of weeks.

Pests and diseases

Like many house plants, common pests include mealybugs and aphids. These are usually easy to pick off by hand.

Small flies around the plant are probably fungus gnats, which breed in moist compost. These can be prevented by adding a layer of gravel or shingle on the top of the compost, to stop the flies laying eggs.

Brown spots on the leaves suggest too much humidity, or water that has been left to sit on the leaves. Simply cut off affected areas to prevent the fungus from spreading.

Leggy growth or thin and rounded stems suggest the plant isn't getting enough light.

Wrinkled leaves indicate the plant hasn't received enough water. This isn't a big problem, simply add water in small doses over a few days, taking care the plant never sits in water, until the leaves have rehydrated.

Brown, soft stems are a sign of root rot. Remove the plant from its pot immediately and allow it to dry out – you may need to cut off affected roots, depending on how badly affected the plant is.