How to Grow Malabar Spinach in Australia

Malabar spinach (Basella alba), also called Ceylon spinach, is a fast, twining vine in the family Basellaceae. It is grown for its thick, glossy leaves and tender shoot tips. It is not true spinach, and it keeps cropping through summer heat, long after spinach has run to seed. In the tropics it grows all year. The usual mistake is sowing it too early, into soil that is still cold.

Three mistakes that matter

1. Sowing into cold soil. Seed is slow to come up in soil below about 18°C, and young plants stall while nights stay cool. Wait for warm spring soil before sowing outside; Starting in pots gives cooler districts a head start.
2. Leaving it to sprawl. Without support the vine runs along the ground, roots where its stems touch the soil, and the leaves end up muddy and hard to pick. Put up a trellis or fence at least 1.5 m high before sowing.
3. Letting the soil dry out. Water stress brings on early flowering, and the leaves turn bitter once flowering starts. Water deeply and often through summer, and keep a straw mulch over the root zone.

When to plant

Sow once the soil holds at least 18°C, the lower end of the 18°C to 24°C range in which the seed germinates best. Frost kills the vine outright, so frosty districts plant out only after the last frost. One spring sowing, kept picked, can crop for four to six months.

At the early edge of a window, raise seedlings in pots and plant them out once the soil warms. Late sowings give a shorter harvest, because shortening autumn days push the vine into flower.

Site, soil and setup

A vine that can reach 4 m needs a permanent spot, a sturdy frame and soil rich enough to keep it in leaf.

Container growing

A pot at least 33 cm wide, holding about 18 L, carries one vine, with an obelisk in the pot or a trellis behind it. Fill it with premium potting mix, never garden soil. Both lines the store sells suit a pot, and the reddish-purple stems of the Red make it as ornamental as it is useful.

• Water: check daily in summer and water before the mix dries, since dry roots bring on flowering.
• Feed: fish and seaweed blend at 25 mL per 9 L, fortnightly from the first true leaves.
• Position: full sun; in frosty districts, move the pot to a sheltered spot in autumn and keep it there until spring.

Sowing Seeds

Sow direct at the foot of the trellis in warm soil, or raise seedlings in pots where spring warms slowly.

Preparing the seed

The hard seed coat slows water getting in, so untreated seed can take three weeks to come up. Soak the seed in water overnight before sowing, or rub each seed lightly on sandpaper to nick the coat (scarification). Either speeds germination. Both methods are set out in soaking and scarification.

Sowing direct

• Sow 10 mm deep, two or three seeds to a station, with stations 20 to 30 cm apart along the trellis.
• Keep the surface damp; seedlings usually appear in 10 to 21 days.
• Thin to the strongest seedling at each station once it has its first true leaves.
• Mulch with straw once the seedlings are up.

Starting in pots

Pots give a head start in the temperate, Mediterranean and cool zones, where spring soil warms slowly.

• Sow two seeds per small pot of seed-raising mix, at the same depth, and keep the stronger seedling.
• Keep the pots warm; a seedling heat mat helps in a cold spring.
• Plant out when seedlings are 5 to 10 cm tall, after the last frost.
• Harden off (accustom seedlings to sun and wind over about a week) before planting out.
• Water in with seaweed solution at half strength, 15 mL per 9 L.

The red-stemmed form is often sold as Basella rubra, an older name for the same species, and it grows exactly as the green does.

Care by growth stage

Heat, water and nitrogen decide this crop. It grows fastest from 20°C to 35°C, stalls when nights stay cool, and answers a regular liquid feed with new leaf. Weeks count from sowing.

Pinching and Harvesting

Picking is the pruning here: every tip taken makes the vine branch, so a well-picked plant grows bushy and stays in leaf. Flowers are the signal to step in.

• Pinch out the growing tip once the vine is about 50 cm long, so side branches start.
• Pick off flower spikes as they form, to keep leaves coming and stop self-sown seedlings.
• Cut back runners that grow past the top of the frame or along the ground.
• In the tropics, feed long-lived vines regularly; vines that go unfed tend to die back after a couple of years.

Companion planting

Good neighbours share its summer heat without sharing its weak point, a root system that root-knot nematodes find easy to invade.

Grows well with

• Corn and amaranth, warm-season crops that do not feed root-knot nematodes, so they also suit the bed before it.
• Lettuce, sown on the shaded side of the trellis, where the vine screens it from the hottest sun.

Keep apart

• Tomatoes, eggplant and beans, which host the same root-knot nematodes, so numbers build up when they follow one another.
• Other climbers on the same frame, such as cucumbers, which compete for light and space and tangle at picking time.

Harvesting Leaves

Start picking from about 8 weeks after sowing, once the leaves are big enough to use.

• Snip shoot tips 15 to 25 cm long, with their young leaves, every week.
• Take large single leaves from the main stems between tip harvests.
• Pick in the cool of the morning, and get the leaves into the fridge quickly.

Picked shoots wilt within a day in summer warmth. Wrap them in a damp cloth or a bag in the crisper, and use them within a week. Eat young leaves raw in salads, or toss tips in a hot pan with garlic for a minute. Leaves added to soups and stews thicken them as they cook.

Common problems

Flowers and bitter leaves. Dry soil and shortening autumn days bring on flower spikes; see Three mistakes and Pinching and Harvesting.

Slow growth in spring. The vine barely grows while nights stay cool, so early plants can sit still for weeks before summer heat sets them going.

Collapse at the first frost. Frost kills the vine, so in cold districts it is grown as a summer annual; Tips sets out how to carry one over.

Purple stains and stray seedlings. Ripe berries hold a purple juice that stains paving and clothes, and dropped berries can come up as seedlings. Picking off flowers prevents both.

Pale, stretched seedlings. Seedlings raised on a dim windowsill stretch for light and flop when planted out. Read more

Pests and diseases

A thick leaf skin keeps Malabar spinach freer of leaf pests and diseases than most greens, so the main trouble is below ground.

Root-knot nematode (Meloidogyne species). Microscopic soil worms knot the roots into galls, and the vine stunts, yellows and wilts. The crop is very susceptible, and damage is worst in warm, sandy soils. Dig in compost or manure, and keep host crops apart as set out in Companion planting. Read more

Aphids (superfamily Aphidoidea). Small sap-sucking insects cluster on soft shoot tips. Hose them off or spray insecticidal soap, and let ladybirds and lacewings finish the job. Read more

Bacterial leaf spot. Spots appear on the leaves and can spread through a crowded vine. Pick off and bin spotted leaves, and thin tangled growth so the leaves dry quickly.

Damping off (Rhizoctonia species). Young seedlings rot at the stem base and topple, most often in cold, wet soil. Sow into warm soil, use fresh seed-raising mix in pots, and water lightly until seedlings grow away. Read more

Prevention first

• Lift a spent plant at the end of summer and check its roots for galls before choosing next year's bed.
• Keep compost and mulch topped up, since organic matter feeds the soil life that preys on nematodes.
• Check the shoot tips weekly for aphids at picking time.
• Water at the base in the morning, so the leaves dry quickly.

Tips

1. Shoot tips about 20 cm long root readily in a glass of water. A rooted tip potted up in autumn and kept somewhere bright and frost free can start next summer's vine. Read more
2. To save seed, let a few late spikes ripen to purplish-black berries, about a month after flowering, then dry them whole for sowing next spring.
3. Pair it with true spinach for greens all year: spinach through the cool months, and Malabar spinach through the heat. Warrigal Greens and Egyptian Spinach, two other summer greens unrelated to it, have their own guides.