Rat’s tail cactus

Rat’s tail cactus: how do you recognise it?

Habit

Trailing or creeping plant with stems up to about 1 m long and roughly 1–2 cm thick; about 0.5 m wide.

Stems

Thin, round, grey-green, slightly ribbed and densely covered in short, fine spines in tufts.

Flower

Tubular, bright pink to cerise, 5–8 cm, along the stems; from April to June.

Fruit

Small, round, red berries after flowering.

Origin

Epiphyte from Mexico, growing on trees and rocks with its stems hanging down.

Flowering: April–June · Plants: April–May · Pruning: June

Why grow it?

• Wonderful trailing plant with stems up to a metre long, lovely in a hanging pot or on a stand.
• Flowers abundantly in spring with bright pink tubular flowers, if it gets a cool winter rest.
• Easy to look after: little water and no special humidity needed.
• Quick and free to propagate from cuttings.
• An unusual houseplant that takes up little space on the windowsill.

Rat’s tail cactus: where does it grow best?

• Bright to part shade: a light windowsill with some morning or evening sun; protect it from fierce midday sun behind glass.
• A free-draining, sandy compost: cactus compost with a third perlite or coarse sand, in a pot with a drainage hole.
• Dry to average: let the compost dry out well between waterings; it dislikes wet feet.
• In summer 15–25 °C; in winter cool and bright at 8–12 °C, never below 5 °C. Ordinary room air is fine.

Light

Sunny or bright, out of direct sun

Potting soil

Cactus compost

Acidity

Neutral

Watering

Sparingly or moderately

Size

1 m tall, 0.5 m wide

Temperature

Minimum 5 °C

Goes well with

• Donkey’s tail: Trailing, leafy stems of a succulent that enjoys the same bright spot.
• Echeveria: Compact succulent rosettes that contrast well with the trailing stems.
• Christmas cactus: Another epiphytic cactus with pink flowers, mostly in winter.
• Hoya: A flowering trailing plant that also likes plenty of light and little water.

Rat’s tail cactus: when and how to plant it?

Plant in April–May.

1. Repot in April–May, as soon as the plant is growing again; if it has buds or flowers, wait until flowering is over.
2. Choose a shallow, wide pot or hanging pot with a drainage hole, about 2–3 cm larger than the rootball.
3. Use cactus compost with a third perlite or coarse sand for good drainage.
4. Set the plant at the same depth as before, fill in with compost and firm lightly.
5. Wait a few days before watering so that damaged roots can heal.
6. Wear gloves when handling the spiny stems.

Care

Water

In summer when the top 2–3 cm of compost is dry; in winter very little, almost dry. Never leave water standing in the saucer.

Feeding

From April to August every 4 weeks, cactus feed at half strength; none in winter.

Light

Plenty of light for abundant flowering; do not turn or move the pot when buds form, or they will drop.

Winter rest

A cool, bright and dry winter of about 8–12 °C is needed for rich flowering in spring.

Repotting

Every 2–3 years in spring into fresh cactus compost; the plant likes a small pot.

Tip: Water regularly in summer and keep it cool and dry in winter: that rest produces plenty of buds. Do not turn the pot when buds appear.

Rat’s tail cactus: when to prune it?

Pruning months: June.

When: It hardly needs pruning. After flowering, in June, shorten stems that are too long or damaged.

How:

• Remove dead, shrivelled or damaged stems at the base with a clean, sharp knife or scissors.
• After flowering, shorten overlong stems to the length you want.
• Let the cut dry for a few days before putting a cutting in compost, if you want to reuse the cut stem.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

May–August: cut off a stem of 10–15 cm, let the cut dry for 2–3 days and insert the cutting in dry cactus compost. Water lightly only after a few days; roots in 3–6 weeks.

Seed

In spring on sandy, moist compost at about 20 °C; it is slow and cuttings are much quicker.

Rat’s tail cactus: how does it get through the winter?

• Not hardy: it needs at least 5 °C and always stays indoors or in a frost-free room.
• Keep it cool and bright in winter at 8–12 °C with very little water, for rich flowering in spring.
• Keep it away from radiators and draughts. From March give a little more water, and the buds will appear.

Diseases and pests

• Root and stem rot: Soft, brown or black patches from too much water. Water less, let the compost dry out well and repot into dry compost if needed.
• Shrivelled stems: Caused by compost that is too dry or by root rot. Check the roots and adjust your watering.
• Mealybugs and scale insects: White cottony clumps or brown scales on the stems. Dab with a cotton bud dipped in alcohol or treat with soft soap.
• No flowers: Too little light or no cool winter rest. Move it into more light and give it a cool, dry winter.
• Bud drop: Caused by moving, turning or draughts at the bud stage. Leave the plant in the same place.

Through the year

• January: Cool, dry winter rest at 8–12 °C.
• February: Cool winter rest. Still very little water.
• March: Water a little more. Buds appear.
• April: Flowering begins. Start feeding.
• May: Flowering. Repot once there are no more buds. Take cuttings.
• June: Flowering ends. Shorten stems that are too long.
• July: Water when the top of the compost is dry. Feed.
• August: Last feed. Keep bright and warm.
• September: Water less.
• October: Move somewhere cooler and water even less.
• November: Winter rest: cool and dry.
• December: Winter rest: cool and bright.

Did you know?

• The name rat’s tail cactus comes from the long, thin, trailing stems, which look like rats’ tails.
• In its homeland of Mexico it grows on trees and rocks, with its stems hanging down.
• It belongs to the epiphytic cacti, like the Christmas cactus: it is not a desert cactus.