Peruvian apple cactus

Peruvian apple cactus: how do you recognise it?

Habit

Columnar cactus with a straight or branched stem, up to about 2 m tall and 50 cm wide indoors.

Stem

Blue-green, with four to eight distinct ribs, sometimes with a waxy bloom.

Spines

Small, sharp spines grouped on fixed spots (areoles) along the ribs.

Flower

Large, white, up to about 15 cm; opens at night and fades quickly. Only on large, older plants.

Fruit

Edible, round to egg-shaped, reddish to yellow, with white flesh and black seeds.

Plants: March–April

Why grow it?

• A sturdy, architectural columnar cactus that instantly gives a room character.
• Very low maintenance: it tolerates drought and needs little water.
• Grows steadily and stays handsome for years, even in a large pot.
• Fits well in a sunny conservatory, a bright corner or on a sunny patio in summer.
• There is a twisted, irregular form, ‘Monstrosus’, which is highly sought after by collectors.

Peruvian apple cactus: where does it grow best?

• As bright and sunny as possible: a south-facing window or conservatory is ideal; it tolerates full sun if it gets used to it gradually.
• Free-draining, sandy cactus compost; neutral to slightly acid.
• Dry: let the compost dry out completely between waterings.
• A warm spot in summer (20–30 °C); cooler and dry in winter, at 5–10 °C.
• Give it room: a 2 m column needs a sturdy, heavy pot.

Light

Sunny

Potting soil

Cactus compost

Acidity

Neutral

Watering

Sparingly

Size

2 m tall, 0.5 m wide

Temperature

Minimum 5 °C

Goes well with

• Echeveria: Low rosettes in soft colours at the foot of the cactus, with the same needs.
• Agave: Another tough, leafy succulent that fits well in a sunny group.
• Aloe vera: Easy, sun-loving and fun in a mixed arrangement of pots.
• Kalanchoe: Colourful flowers in winter or spring beside a bare cactus.
• Succulents and cacti: A group of pots with different shapes makes a lovely sunny corner.

Peruvian apple cactus: when and how to plant it?

Plant in March–April.

1. Repot in March–April, when the plant starts growing again.
2. Choose a pot with a large drainage hole, preferably terracotta. The pot should be only slightly larger than the rootball.
3. Use cactus compost or mix potting compost with a third of coarse sand, perlite or pumice.
4. Hold the plant with folded newspaper or thick gloves and set it at the same depth as before.
5. Wait about a week before watering so that damaged roots can heal.
6. Spread a thin layer of grit or fine pebbles on the surface to guard against rot at the base of the stem.

Care

Water

In summer, water only when the compost is completely dry, then thoroughly. In winter hardly at all or not at all.

Feeding

From April to August, a cactus feed or one low in nitrogen every four weeks.

Light

As much light as possible. In summer it may stand outside; acclimatise it gradually to the sun to prevent scorching.

Temperature

Summer 20–30 °C; winter cooler, 5–10 °C. Below 5 °C it can be damaged.

Repotting

Every two to three years in spring, or when the pot becomes too small or too light.

Dusting

Wipe or rinse off dust with a soft brush or a gentle stream of water; this lets it take up light better.

Tip: Give it plenty of sun and a free-draining cactus compost. In summer water only when the compost is dry, and keep it dry in winter at 5–10 °C.

Peruvian apple cactus: when to prune it?

When: It is hardly pruned. If it gets too tall you can cut off the top in spring or summer.

How:

• Cut the top off straight across with a clean, sharp knife; the stem then often sends out side shoots.
• Let the cut surfaces, on both the stem and the cut piece, dry for one to two weeks before continuing.
• The cut piece can serve as a cutting; stand it dry and let it root.
• Remove soft, brown or rotten parts with a clean knife back to healthy tissue.

Caution: Sharp spines: use folded newspaper or thick gloves when cutting and repotting. Keep it out of reach of children and pets.

Pruning calendar and basic rules

Propagation

Cuttings

In spring or summer: cut a piece from the top or a side branch, let it dry for 1–2 weeks and stand it upright in dry cactus compost. Water only once roots have formed.

Seed

Sow fresh seed from the fruit in spring in sandy compost at 20–25 °C. It is slow; the seedlings stay small for a long time.

Peruvian apple cactus: how does it get through the winter?

• Not hardy: it cannot take frost and must overwinter indoors, frost-free.
• In winter keep it bright and cool at 5–10 °C, and water hardly at all or not at all.
• If you cannot keep it cool, leave it in a bright spot and give just a little water now and then; in winter it hardly grows.
• In autumn bring it in before night temperatures fall below 10 °C.

Diseases and pests

• Stem rot: The stem turns soft, brown or black, especially at the base. Usually caused by too much water, especially in the cold. Cut away the affected part back to healthy tissue and let it dry; water less.
• Mealybugs and scale insects: White cottony tufts or brown scales between the ribs and spines. Dab with a cotton bud dipped in alcohol, or treat with a mild soap solution.
• Thin, pale growth: The top grows thinner and more pointed towards the light. Give it more light; the part that has already grown thin does not recover.
• Sunburn: White or brown, dried-out patches after sudden sun. Always acclimatise the plant to the sun gradually.

Through the year

• January: Rest. Bright, cool (5–10 °C) and dry.
• February: Rest. Keep dry.
• March: Repot. Only then water very sparingly.
• April: Repot. Gradually water more as growth starts. Begin feeding.
• May: After the last frosts slowly acclimatise to the sun or put outside.
• June: Water when the compost is dry. Feed every four weeks.
• July: Growing season. Water mostly in warm weather.
• August: Last feed. Take cuttings.
• September: Less water. Stop feeding.
• October: Bring indoors before it gets cold. Almost stop watering.
• November: Rest. Dry and bright at 5–10 °C.
• December: Rest. Keep dry.

Did you know?

• In Curaçao the plant is called kadushi and is used as a living fence; the young parts are also eaten there in soup.
• The large white flowers open for only one night and in the wild are visited by nocturnal animals such as bats and moths.
• In nature it can grow to about 10 m tall, while indoors it stays much smaller.