How to grow banana and plantain

Pick deep, rich soil that drains well — a deep loam is ideal. After heavy rain the water should soak away, never sit in pools; banana rots in waterlogged ground.

Banana likes soil that is only slightly sour to neutral, not strongly acid. Only worry about sourness if a soil test — or past crops that stayed yellow and stunted even when you fed them — says the soil is very sour. If it is, spread and work in the recommended lime a few months before planting to sweeten it, the way you would for maize; lime is slow, so late liming won't help.

On a slope, plant on the gentle lower and middle slopes where the soil is deep and moist but water still drains; avoid the very bottom, where water and cold air collect.

Ask about the field's history. Do not plant where banana wilt (BXW) or Panama disease has killed plants before — both diseases survive in the soil and old corms for years and will strike your new mat. Learn what they look like so you can judge a plot: BXW makes plants wilt fast, ripen a few fingers yellow too early, and ooze a yellow slime from a cut stem; Panama disease (also called Fusarium wilt) makes the older, lower leaves turn yellow and collapse until they hang down around the trunk like a dead skirt, and the inside of a cut stem base is streaked reddish-brown.

Match your type to your altitude: plantain and dessert banana like the hot, humid lowlands; cooking banana / matoke does best in the cooler highlands and struggles high up on cold mountains.

If you can, choose a spot near your home or a path — you will walk it often to scout, cut suckers, and carry heavy bunches out.

Best of all: use tissue-culture plantlets from a trusted nursery — they are grown clean and carry no weevil, nematode or virus. If you can get them, they are worth it.

If you use suckers, take sword suckers — young ones with a narrow, spear-shaped leaf and a fat corm — from a healthy, high-yielding mat you know. Avoid broad-leaved water suckers, and never take suckers from a field with wilting, stunting, or a bunched-up top.

Pare the corm: with a clean knife, shave off the outer skin until it is white and clean. Brown or black tunnels you uncover are weevil damage; dark, rotten root bases are nematode. Cut them out — if the corm is riddled, throw that sucker away.

Hot-water dip (if you can): after paring, dip the corms in water at about 50 °C for ~20 minutes — hot enough that you cannot keep your hand in it and it steams, but not boiling. This kills nematodes and weevil grubs hiding inside. Then plant soon after.

Keep pared, treated material in the shade and plant it quickly. Never mix it back in with untreated suckers.

Mark your planting spots about 2.5 m apart each way — that is roughly two to three normal strides between plants, the same distance in both directions. Wide spacing lets air move (less leaf disease) and light in.

At each spot dig a big hole — about knee-deep and as wide as a large basin (30–60 cm across). Banana likes room.

Keep the dark topsoil in one pile and the poorer subsoil in another.

Mix the topsoil with one or two basins of well-rotted manure or compost (and a handful of wood ash for potassium if you have it), and put that rich mix back in first, where the roots will sit.

Do this before the rains, so the holes are ready and you can plant the moment the ground is properly wet.

Plant when the soil is properly wet — at the start of the rains, or after a good watering under irrigation. The young corm must never dry out.

Set the sucker or plantlet in the prepared hole so the corm is covered but the growing point sits at soil level — about a hand's depth. Firm the rich topsoil-and-manure mix around it so there are no air pockets.

Keep the spacing even at about 2.5 m each way (two to three strides) — your recommendation gives the exact spacing for your type.

Mulch heavily straight away: lay a thick mat of dry grass, leaves or old banana trash around the plant, about a hand-span deep, out to arm's length. Mulch holds water for the shallow roots and slowly feeds back potassium, banana's most-needed food.

Leave a hand-span gap between the mulch and the base of the pseudostem (the soft false 'trunk' — really a bundle of rolled leaf-sheaths) — mulch piled against it stays wet and hides weevils.

Keep the soil around the mat moist at all times — push a finger in past the mulch and water whenever the top of the soil is drying out.

Water every 7–10 days, and more often in heat or on sandy soil that dries quickly. Give roughly a full bucket (a 20-litre debe) at the base each time, and more as the plant grows.

Water onto the mulch, not bare soil — the mulch stops it running off and slows evaporation, so less water does more.

But do not waterlog — banana rots in standing water. If water pools around the corm, open a small channel and drain it away.

Walk your young plants about once a month and look closely at each mat.

Weevil: look for plants that are weak or stunted for no clear reason, and scrape the soil at the base for the black adult weevil or tunnels in the corm. Damage here means the planting material carried it in.

Nematode / toppling: look for plants that lean or topple with the corm still in the ground — a sign the roots have been eaten away. Toppled young plants mean nematodes came in on the suckers.

Wilt (BXW): look for yellowing or wilting leaves, and if you cut a suspect stem, a yellow slimy ooze. This is the most dangerous disease of all.

Act on what you find. BXW → cut that whole plant down at soil level today, and sterilise your knife (flame or bleach) before touching another plant. Weevil or nematode toppling → destroy the affected corm, and next time plant only pared, hot-water-treated or tissue-culture material there. If you find nothing wrong, keep walking the field monthly.

Aim for a follow-the-leader mat of three: one mother (the biggest, carrying or about to carry the bunch), one daughter/follower (about half her size), and one peeper (just poking through). That's it.

Every month or so, remove the extra suckers — keep the strong sword suckers (narrow, spear-like leaves) in the right positions and cut out the rest.

To kill a sucker properly, cut it off at ground level and gouge out its growing point in the centre with a sharp spade or a twist of the knife — otherwise it just grows back.

Choose the followers on the side you want the mat to move toward — over the years the mat 'walks' in the direction of the suckers you keep.

Every few weeks, look over the leaves for grey-black streaks and blotches (Black Sigatoka) and for leaves that are dead or hanging brown.

Cut off the badly-spotted and dead leaves where they join the stem, with a clean cut.

Lay the cut leaves flat on the ground as mulch, or bury them — don't leave them hanging, where the disease keeps spraying spores onto healthy leaves.

Don't over-strip. Keep all the healthy green leaves you can — the plant needs plenty of working leaves (especially as the bunch fills) to make a full bunch.

Keep the mulch topped up thickly around the mat — old banana leaves and stems, dry grass, crop residue. As it rots it feeds back a lot of potassium for free and holds moisture.

Feed a potassium fertiliser (such as muriate of potash) and a little nitrogen (urea or CAN, or plenty of well-rotted manure) a few times through the season — your recommendation gives the amounts for your mat.

Spread it in a ring on moist soil about one to two hand-spans out from the stem, over the feeding roots — not against the stem — then cover it with mulch or a little soil.

If you have wood ash, work a couple of handfuls into the mulch ring — it is rich in potassium and helps fill the bunch.

Banana also needs some magnesium (Mg), which well-rotted manure and compost help supply. If the older, lower leaves yellow between the veins while the veins themselves stay green, that is magnesium hunger — feed more manure, or a little magnesium fertiliser (such as Epsom salts) if you can get it.

Feed when the soil is moist (after rain or watering) so the food dissolves down to the roots instead of gassing off or sitting dry.

Walk the field about once a month, looking over each mat's leaves, stems and base.

Black Sigatoka: grey-black streaks and blotches on the leaves. Cut off the worst leaves (see the de-leaf task) and keep the air moving.

Wilt (BXW): any plant with yellowing, wilting, uneven early ripening, a blackened male bud, or yellow ooze from a cut. There is no cure — cut the whole stem down at soil level at the first symptom and sterilise your tool between every plant.

Bunchy-top virus: a plant whose new leaves come out short, narrow and upright, bunched into a rosette at the top, with dark-green dot-and-dash streaks — short dots and longer dashes — running along the midribs and leaf stalks. No cure — dig out the whole stool (the mat), corm and all, so it can't regrow or feed the aphids that spread it.

Weevil: stunted plants; scrape the base for the black adult or corm tunnels. Set split-pseudostem traps (a length of cut false trunk laid flat, checked for adults sheltering underneath) to catch adults, and chop up old corms and stems so they can't breed. If nothing is over threshold, keep scouting monthly.

Watch the emerged bunch. Once the fruit hands (the fingers) have all set, only the slim stalk and the purple male bud hang below them.

About a hand's length below the last hand, snap the male bud off by hand or knock it off with a forked stick — do not cut it with a knife.

Using a stick and leaving no cutting wound means there is no fresh cut for the wilt bacteria to enter, and no blade to carry disease from plant to plant.

Drop the removed bud away from the mat; don't leave it hanging in the plantation.

Walk the flowering plants every week while bunches are shooting — more often than the rest of the year.

Look at the male bud and flowers for insects, and at the whole plant for a few fingers ripening yellow early while the rest are still green — a classic wilt sign.

If you suspect wilt, cut into the pseudostem: a yellow, slimy ooze confirms BXW.

On any wilt sign, act today: cut the whole affected stem down at soil level, leave it in place (don't carry it out), and sterilise your tool (flame or bleach) before touching another plant.

Check that every shooting plant has had its male bud removed with a forked stick — that alone cuts insect-borne wilt sharply. If all looks clean, keep the weekly walk up through shooting.

As soon as the bunch is clearly heavy and pulling the plant to one side, prop it — don't wait for a storm.

Wedge a forked pole (a Y-shaped stick) under the bunch stalk or against the leaning side of the pseudostem to take the weight.

Or tie the pseudostem with twine or banana fibre to a strong neighbouring plant or a stake, sharing the load.

Angle the prop so the bunch hangs clear of the stem and leaves, so the fingers don't rub and scar.

Keep the soil moist right through bunch filling — don't let the plant wilt while it is carrying a bunch.

Water every 7–10 days, more often in heat and on sandy soil; give more now than earlier — a bunch-filling plant drinks a lot.

Keep the mulch thick around the mat; water onto the mulch so it soaks in and doesn't run off, and top it up as it rots down.

Still don't waterlog — keep any pooling water draining away from the corm.

Once a month, check the leaves for fresh grey-black Sigatoka and the base for weevil signs and any leaning.

Cut off badly-spotted and dead leaves, but keep every healthy green leaf — the plant needs them to finish filling the bunch.

Weevil / toppling: if plants lean or you find corm tunnels, prop the bunch, set traps, and plan to destroy that old corm after harvest.

If a plant is clearly failing or toppling with a nearly-full bunch, harvest that bunch early rather than lose it to the ground.

Check the bunch: it's ready at three-quarters full, when the fingers have gone rounded and plump and their sharp lengthwise ridges have flattened, and the skin has lightened from dark to a pale yellowish-green.

To cut a tall plant, have one person notch the pseudostem partway up so it bends over slowly, while another catches the bunch on a padded shoulder — never let it crash to the ground.

Cut the bunch stalk off with a clean knife, leaving a short handle of stalk to carry it by.

Lay the bunch on cushioning (leaves or grass), in the shade — don't stack heavy bunches on each other.

Move it to market or store quickly — banana ripens fast and every knock turns into a black bruise; a bruised, over-ripe bunch fetches far less.

If the fingers are still thin and sharply angular and the skin is still dark green, it isn't ready — leave it another week or two and check again. Only cut early if a threat (wind, wilt, a failing plant) forces you, and expect it to ripen unevenly.

After harvest, cut down the spent (mother) pseudostem — the one that carried the bunch. It will never fruit again.

Chop the felled stem into pieces and spread them as mulch around the mat. The soft trash rots fast and returns a lot of potassium and moisture to the soil.

Spread the chopped pieces thin, and keep them off the base of the living stems — a wet pile against a stem is a weevil breeding site.

Check the mat still has its follow-on stems — the daughter now becoming the mother, and a peeper coming behind — and de-sucker back to about three if needed.

Top up mulch and feeding (potassium first) so the ratoon (the next crop off the same mat) starts strong — the mat then repeats flowering to harvest every 9–15 months for several years.