Moringa

About

Moringa grows faster than almost any other tree, reaching 3 m in its first year from seed and flowering in the same season. Everything above the root is useful, which is why aid agencies have planted it across the dry tropics for decades.

The leaves are the main crop. They are small, soft, and unusually rich in protein, vitamin A, vitamin C, calcium and iron for a leafy green, and they are cooked fresh or dried and powdered. The powder in health food shops is this.

The pods are the drumsticks of South Indian cooking, long ribbed green rods that go into sambar whole, where the flesh is scraped out of the fibrous casing at the table.

The seeds do something else again. Crushed and stirred into muddy water they carry a cationic protein that clumps suspended particles and much of the bacterial load, dropping both to the bottom. Rural water treatment programmes across Africa and Asia use exactly that.

Appearance and character

An open deciduous tree, 10 to 12 m where it is happy, kept to 2 or 3 m in a pot by cutting it back hard.

Growth is fast and the wood is soft and brittle. Branches snap in wind and under their own weight, and the tree is not one to plant where that matters.

The root of a young plant swells into a tuber, which is what carries it through a dry season.

Leaves are the identification. Each is tripinnate, divided three times, so a single leaf 30 to 60 cm long is made of hundreds of small pale green oval leaflets a centimetre across. The whole thing looks like a fern rather than a tree leaf, and it drops as one unit.

Flowers are cream-white, 2 cm across, fragrant, in loose drooping panicles, appearing within a year of sowing.

Pods are long, slender, three-angled and ribbed, 20 to 50 cm, green ripening to brown, splitting to release winged brown seeds.

Seeds are round, dark brown, about 1 cm, with three papery wings, and they float.

Where it is from

Moringa oleifera is native to the southern foothills of the western Himalaya, in north-western India and probably Pakistan, in dry deciduous forest and scrub.

Indian cultivation is ancient, and the tree appears in Sanskrit medical texts as shigru. Tamil, Telugu and Hindi kitchens have used the pods and leaves for millennia.

It travelled early through the Arab world into Africa and, later, with Indian migration, to the Caribbean, the Philippines and the Pacific. Filipino cooking uses the leaves as malunggay in soups.

Development programmes spread it further in the twentieth century, on the grounds that it grows fast on poor dry soil, tolerates drought, and produces food within a year of sowing.

India remains by far the largest producer, growing drumsticks as a field crop in Tamil Nadu, Andhra Pradesh and Karnataka.

How it grows

Sow seed fresh in spring at 25 to 30 deg C. It germinates within one to two weeks and loses viability within a year, so old seed is a waste of time.

Sow into deep pots, since the seedling puts down a taproot fast and resents being checked.

Use a gritty free-draining compost. Wet compost kills seedlings faster than cold does.

Grow in a heated greenhouse or conservatory outside the tropics, in the largest pot you can manage.

Give full sun and as much heat as possible, 25 to 35 deg C in summer.

Water sparingly and let the compost dry between waterings.

Cut it back hard. Left alone it makes a leggy brittle pole; cut to 1 m each spring it makes a bushy plant with far more leaf, which is how it is managed for leaf production everywhere it is grown.

Harvest leaves by stripping the leaflets from the stalks, taking no more than a third of the plant at once.

Keep it dry and above 10 deg C in winter, when it will drop its leaves and sit dormant.

Cuttings of hardwood 1 m long root readily in the tropics, and less readily in a heated greenhouse.

Through the seasons

March and April are for sowing fresh seed in warmth and for cutting an established plant back hard.

May and June are rapid growth, and a seedling can reach a metre in this period alone.

July and August are the main leaf harvest, and the months to take cuttings if you want more plants.

September brings flowers on a plant in its second year or later.

October is when to reduce watering as the light drops.

Winter is dormancy. Keep it above 10 deg C, nearly dry, and expect it to drop every leaf.

Late winter is the point to check the compost is not damp, since a cold wet root is what kills it.

Care difficulty

Moderate, and the failures are nearly all the same failure.

Overwatering kills more moringa in cultivation than cold does, and a wet root in a cool greenhouse is fatal.

Germination is easy with fresh seed and impossible with old seed.

Growth is extraordinarily fast, which makes it a rewarding plant to raise.

Winter is the test, since it wants 10 deg C as an absolute floor and dry compost.

Hard annual pruning is what turns a brittle pole into a productive leaf bush.

Pods outside the tropics are unlikely, and leaves are entirely achievable.

Watering

Water once a week through the growing season.

Let the compost dry well between waterings, which suits a dry-country tree.

Increase slightly in a hot bright spell when the plant is growing fast.

Reduce sharply from October.

Keep it nearly dry through winter dormancy, watering perhaps once a month.

Never let it stand in a saucer of water at any time of year.

Warning signs, diseases and pests

Wilting in damp compost is root rot, and it is the commonest way to lose the plant.

Seedlings collapsing at soil level are damping off from cold wet compost.

Leaf drop in autumn is normal deciduous behaviour rather than a problem.

Leaf drop in July means cold, drought, or a sudden move.

Fine speckling with webbing is red spider mite under dry glass.

A tall bare stem with leaves only at the top means the plant needs cutting back.

Branches snapping is the wood being what it is, and a wind-free position and hard pruning both help.

Blackened shoot tips after a cold night are chill damage below 10 deg C.

Growing environment

A heated greenhouse or a bright conservatory.

Full sun.

Minimum 10 deg C in winter, with 25 to 35 deg C in summer.

Low to moderate humidity, and good ventilation.

Light gritty sharply drained compost.

A deep pot for the taproot, and the largest one you can manage.

Shelter from anything that could break the brittle branches.

Feeding

Feed lightly. Moringa evolved on poor dry soil and rich feeding makes soft growth that snaps.

Give a balanced liquid feed monthly through summer at most.

Skip manure and heavy nitrogen entirely.

Add grit to the compost rather than organic matter.

Feed nothing from October to March.

Top dress with fresh gritty compost each spring after cutting the plant back.

Troubleshooting

How fast does it grow? Three metres in the first year from seed in the tropics, and a metre or more in a heated greenhouse. It is the fastest tree in this collection.

Why did mine die over winter? A wet root in a cool greenhouse, in nine cases out of ten. Keep it above 10 deg C and nearly dry through dormancy.

Can I eat the leaves raw? In small amounts, yes, and they are usually cooked. A large quantity of raw leaf is laxative.

What about the root? Leave it. Moringa root and root bark contain spirochin and are not food, whatever the horseradish tree name suggests.

Will I get drumsticks outside the tropics? Unlikely. Pods need a long hot season and a large plant. Leaves are the realistic crop here.

Is the powder in health food shops the same thing? Yes, dried and milled leaf from this species.

Do the seeds clean water? They flocculate it. Crushed seed releases a protein that clumps suspended particles and much of the bacterial load so they settle out. It reduces turbidity and contamination rather than sterilising the water.

My plant is a tall bare stick. It needs cutting back. Take it down to about a metre each spring and it will branch into a leafy bush.

My seed never germinated. Moringa seed loses viability within about a year. Buy fresh seed and sow it at 25 to 30 deg C in gritty compost.

Is it safe in pregnancy? The leaves are eaten widely, and root, bark and seed preparations are avoided, since they have a long traditional use as abortifacients. Ask a midwife or doctor rather than relying on a plant page.