How to grow guava

Pick a spot where water drains away after rain — never a dip or hollow where puddles sit. Guava puts up with poor, stony, sour or even salty soil, but wet feet rot its roots.

Test the drainage: dig a hole about knee-deep (half a metre), fill it with water, and come back a few hours later. If water is still standing, choose a better-drained spot or plan to plant on a raised mound.

Leave plenty of room. A guava spreads wide, so allow 5 to 6 big strides between trees (5–6 m) each way. Squeezing them closer (3×2 m) crowds them and gives smaller fruit.

Get the right kind of tree: a grafted or air-layered plant — that is, a good fruiting variety joined onto tough roots, or a branch that was rooted while still on the mother tree. These fruit in year 1–2 and give exactly the parent's fruit. Avoid seed-grown trees — they are slow and each one fruits differently.

Plant at the start of the rains (or when you can water), so the young tree settles in with moisture around its roots.

Dig a good pit, about half a metre across and deep (two to three hand-spans). Mix the topsoil back with a little well-rotted manure or compost.

Set the tree at the right spacing — 5 to 6 big strides apart (5–6 m) each way — with the old soil mark on the stem level with the ground. Keep the graft join (the knob low on the stem) well above the soil; burying it invites rot.

Backfill, and firm the soil down around the roots with your foot so there are no air pockets.

Water it in well straight away — a full bucket — to settle the soil around the roots. Keep watering through the first dry months while it takes hold.

From about a month after planting, walk your trees every 4–5 weeks (about once a month) and look them over closely — leaves, new shoots, and the base of the trunk.

Guava wilt: look for a tree that suddenly yellows, wilts and dies back, often on one side, with black, rotting roots when you scratch down. There is no cure — dig out and burn the whole tree, and do not replant guava in that exact spot.

Scales: look for tiny limpet-like bumps stuck along stems and leaf veins, sticky sweet droplets (called honeydew), and black sooty mould growing on the stickiness.

Mealybugs: look for white cottony blobs tucked into leaf joints and under the leaves, with the same sticky droplets and black mould.

For a few scales or mealybugs, wipe them off or prune out the worst shoot; a strong squirt of water or soapy water knocks them back. Keep the ground around the tree weed-free and tidy.

From a month after planting, through the growing season, feed a small handful of compound (N-P-K) fertiliser every 1–2 months — your recommendation gives the exact amount for the tree's size.

Guava wants potash (K) more than nitrogen, plus a little zinc and boron — so reach for a balanced or potash-rich compound, not a straight nitrogen fertiliser. A ring of well-rotted manure or compost around the tree helps too.

Spread it in a ring around the tree, out near the leaf edges (the drip line) where the feeding roots are — never against the trunk. Scratch it lightly into the soil and water it in.

Keep the young tree watered in dry spells — guava is drought-tough once established, but a young tree needs regular water to grow away.

About a year after planting (roughly 10–14 months), once the young stem is well established, cut the single main stem back low — to about knee height (0.3–0.6 m from the ground) — with a clean, sharp blade.

This makes the tree push out several side shoots. Keep the 3–4 strongest, best-spaced ones pointing outwards in different directions; rub off the rest. These become your framework ('scaffold') branches.

When those chosen branches reach about thigh height (0.6–0.9 m), pinch out each tip so they branch again — building a low, open, spreading tree.

Cut on a dry day with a clean blade, and take off any dead or crossing shoots as you go.

Through the growing season, walk the trees every 4–5 weeks (about once a month) and check the leaves, new shoots and the base of the trunk.

Guava rust: look for powdery, bright yellow-to-orange dust on the newest leaves and shoot tips; badly hit tips twist, brown and die back. It spreads fast in warm, wet weather — cut out and bag affected tips.

Anthracnose: look for dark, sunken spots on leaves and dieback of shoot tips (later it spots and rots the fruit). Prune out and destroy affected wood.

Algal leaf spot: look for raised, velvety grey-green to rusty spots on the older leaves — usually mild; improve airflow and it fades.

Guava wilt: keep watching for whole-branch or whole-tree yellowing and wilting with black rotting roots — remove and burn affected trees.

Anything you cut out that is diseased, carry away and burn — don't drop it under the tree, or it re-infects.

Prune early in the growing season, in the first month or two, on a dry day with a clean, sharp blade.

On a young tree, keep building the frame: hold to 3–4 well-spaced main branches, and tip new shoots at about thigh height (0.6–0.9 m) so they branch into an open cup.

On a bearing tree, thin and shorten each year: take out dead, diseased and crossing wood first, then open the centre so light and air reach right inside. Shortening the shoots pushes out the new growth that flowers.

Keep the tree low enough to pick from the ground — head it back rather than letting it climb.

Carry away and burn all diseased prunings; don't leave them lying under the tree.

Start this about a month before you want the tree to flower — count back so the fruit will ripen in a dry period (fruit takes about 3–5 months from flower to ripe).

Prune the tree lightly to push out fresh shoots — remember, guava flowers on new growth.

Then withhold water for a short spell to stress the tree (some growers call this a 'bahar'). The leaves may droop a little — that is the point.

Then water well. The tree answers the return of water with a burst of flowers all together, instead of a few at a time.

Keep bees around: leave some flowering plants nearby and don't spray insecticide on open flowers. Bees carry pollen from flower to flower and set more, bigger fruit.

From flowering, as the first fruit sets, check the trees every 5–7 days.

Hang a monitoring trap or two in the trees to catch the first flies and tell you they have arrived.

Fruit-fly signs: look for tiny sting marks (pin-pricks) on the young fruit, soft or weeping spots, and fruit that drops early; cut a suspect fruit open and you may find small white maggots inside.

Pick up and destroy every fallen fruit — burn it, bury it deep, or seal it in a bag in the sun. Fallen stung fruit is exactly where the next wave of flies breeds.

Get ready to bag fruit and to bait-spray the moment fruit sets and stings begin — see the fruit-fly task in the next stage.

From about three weeks after flowering (as the little fruits form) right up to harvest, work the trees every 3–4 days — this is the busiest job of the season.

Bag the fruit while it is small — about 3–4 cm across, the size of your top thumb-joint. Slip a paper or newspaper sleeve (or a fine net bag) over each fruit and tie it. Bagged fruit can't be stung.

Hang monitoring traps in the trees so you know when fly numbers climb.

Start protein-bait spraying on the first stings or the first rise in trap catches — do not wait for maggoty fruit. Protein bait is a sticky, sweet lure mixed with a little insecticide: you spot-spray a small patch of leaves on each tree, not the whole tree, and the flies come to feed and die.

Collect and destroy every fallen and stung fruit, every few days — burn, bury deep, or seal in a bag in the sun. This one habit starves the next generation and matters as much as any spray.

When you spray any bait or insecticide: cover your skin, eyes, nose and mouth, spray in the cool of the day with the wind behind you, keep it off food, wait the number of days the label says before picking (the pre-harvest interval), and wash well afterwards.

Once a week, from about three weeks after flowering until harvest, look over the developing fruit and the shoot tips.

Anthracnose signs: look for dark, sunken, firm spots on the fruit (with pinkish ooze in wet weather), and fruit that hardens, blackens and dries on the tree (mummifies); on shoots, look for tip dieback.

Pick off and carry away every spotted, rotting or mummified fruit — and any dead shoot tips — and burn or bury them. Left on the tree, each one showers spores onto the healthy fruit.

Keep the canopy open (from your pruning) so fruit dries quickly after rain — the fungus needs wetness to spread.

While the fruit is swelling — from about three weeks after flowering — water every 7–10 days (more often in heat and on sandy soil) to keep it filling. This flowering-to-fill stretch is the tree's thirstiest; don't let it run dry now.

Water at the soil, out around the drip line — not over the fruit and leaves, since wet fruit and foliage invite rot.

As the fruit nears ripe (the skin starting to lighten), ease off and then stop watering, so the fruit ripens in dry soil.

Let the fruit ripen dry — this holds the sweetness and stops splitting.

Start when the first fruit reaches colour-break: the skin lightens from deep green to pale green or yellowish, the fruit gives slightly to a gentle squeeze, and it begins to smell sweet.

Pick over several passes, every 5–7 days for 2–4 weeks, taking only the fruit that has reached that stage each time — the rest will follow.

Twist or clip each fruit off with its short stalk, and handle it gently — guava bruises easily, and every bruise becomes a rot spot.

For selling or carrying far, pick at mature-green to colour-break and let it finish ripening off the tree; for eating now, pick a little riper.

Lay picked fruit gently in a shallow basket or crate, not a deep heap that crushes the bottom layer, and keep it out of the sun.

On the day you pick, get the fruit out of the sun and into shade or a cool room straight away — heat is what ages it fastest.

Sort as you go: set aside any bruised, stung, cracked or over-ripe fruit to use or process first, and keep the sound fruit for market.

Handle gently and keep it in shallow layers so the fruit underneath isn't crushed.

To hold it longer, keep it cool at about 7–10 °C (2–3 weeks) — but not below about 5 °C for long, or it takes cold damage (pitted skin, off flavour, won't ripen right). At room temperature, plan to use or sell it within 3–4 days.

Process the surplus you can't sell fresh — guava is rich in vitamin C and full of natural pectin, so it sets well into juice, jam, jelly or puree. Cook it up while it's sound rather than watch it rot.