The Annona genus — sometimes written Anona, and known in some regions as sop — gives us some of the best soft tropical fruit there is, and one of the most frustrating flowering habits in the garden. These trees are easy to keep alive and hard to make productive. If you understand the one quirk in their flowers, everything else about growing them falls into place.
Why an Annona flowers heavily and sets so little fruit
Annona flowers are small and green-yellowish, and they are protogynous: each flower opens first in a female phase, receptive to pollen, and only afterwards turns male and sheds pollen of its own. Both phases occur on the same tree, but they happen at different times.
That timing offset is the entire problem. When a flower is receptive, the tree around it is usually not yet releasing pollen; by the time pollen is being shed, that flower has already passed out of its receptive phase. A lone, unassisted tree therefore spends a whole season with pollen and receptive flowers that keep missing each other, and the result is a beautiful tree carrying a handful of fruit. The stated difficulty with this genus — low amount of fruit caused by the difference in blooming hours between male and female flowers — is exactly this.
There are three practical answers, and they stack.
1. Grow two trees
Two trees planted near each other substantially increase the chance of pollination, simply because they will not run their flowering clocks in perfect step. One tree sheds pollen while its neighbour still has receptive flowers open. This is the least effort for the biggest gain and it is the standard recommendation for the genus.
2. Hand pollinate — and keep the tree small so you can
Hand pollination is the reliable method rather than the hopeful one, and it is the reason experienced growers deliberately keep an Annona short. Flowers you cannot reach are flowers you cannot pollinate, and this genus will happily climb to 10 m if you let it.
3. Graft several cultivars, or two Annona species, onto one trunk
If you only have room for one tree, grafting more than one cultivar — or even a second Annona species — onto the same trunk gives you the pollination benefit of a pair in a single footprint. When you do this, let the grafted limbs grow into each other rather than training them apart; the intermingled canopy puts pollen and receptive flowers close together and increases the amount of fruit.
How to hand pollinate an Annona, step by step
- Collect male-phase flowers. Take flowers that have turned male and are carrying pollen. Choose them from a weak part of the tree, or at least from somewhere that is not right beside the female flowers you intend to pollinate — you are sacrificing those flowers, so take them where they cost you least.
- Check they still have pollen. If a flower has already released its pollen it is of no further use to you. Discard it and take another.
- Store the flowers properly if you are not using them at once. Keep them somewhere dark, humid, cool and ventilated. Dry warm air ruins pollen quickly; stagnant damp air rots the flowers. You want cool and moist with air movement.
- Gather the pollen with a cotton swab. A soft swab picks up pollen without damaging it and lets you see how much you are carrying.
- Transfer it to flowers in their female phase — the ones that are open and receptive. Dab rather than scrub.
- Repeat through the flowering period. Flowers open in waves, so one session is never enough.
Growers usually do this in the late afternoon or evening and apply the pollen the following morning, working with the daily rhythm of the flowers rather than against it.
Seed, cutting, air layer or grafted tree?
All four routes work: a nursery plant, cuttings, air layering, or seed. Annona is not difficult from seed — but seed is a lottery, and a grafted tree is what you want if the goal is fruit rather than foliage. Grafting buys you:
- Known flavour, instead of finding out in year four that you raised a dull one.
- Fewer seeds in the fruit and larger fruit — cultivar traits you cannot fertilise into a seedling.
- Fewer years to the first crop.
- A longer harvest season.
- Several cultivars or species on one trunk, which as described above is also your pollination fix.
A sensible middle path: raise seedlings, and if the fruit turns out small or poorly flavoured, graft the tree over rather than starting again from scratch.
Sowing Annona seed
- Sow in spring, in warm weather.
- Dig a small hole and set the seed so it is covered by about 2 cm (1 inch) of soil.
- Cover it and keep the soil moist at all times. Drying out at the wrong moment is the usual reason seed fails.
- Give full sun and warmth.
Climate, and when to plant
Annona grows in tropical, subtropical and Mediterranean climates, in hardiness zone 10 and above. It is an evergreen by nature, but in cold weather it behaves like a deciduous tree and drops its leaves — treat that as a stress signal rather than a normal seasonal habit.
Planting season narrows as the climate cools:
- Zone 10a — spring only.
- Zone 10b — spring to summer.
- Zone 11a — spring to autumn.
- Zone 11b and warmer — all year.
The logic is simple: the colder your winter, the more growing season a new tree needs before it meets it.
Planting
- Dig a hole 50% larger than the root ball.
- Add organic matter, dead leaves and humus, put back some of the soil and mix them together.
- Set the tree in and backfill, firming lightly but firmly enough that it will not fall over.
- Stake it if it needs support. If it is unstable because it is top-heavy, prune the canopy back — reducing top growth lets the roots establish instead of struggling to anchor growth they cannot yet hold.
- Water twice on the first day, then every day for two weeks.
- Mulch the surface.
Water, feeding and soil
Annona wants rich soil and an average to large amount of water. Steadiness matters more than volume — swings between bone dry and saturated stress developing fruit.
Feed four times a year. While the tree is young, weight the feed towards nitrogen to build the frame and foliage you need before fruiting starts. Keep adding humus and organic matter, and keep the ground under mulch: it holds moisture, evens out soil temperature and feeds the soil as it breaks down.
Pruning: build a dense, low canopy on purpose
Prune once a year in winter, or after the fruit has been picked.
The method runs against normal fruit-tree instinct. Instead of opening the centre, you cut the outer branches and let the remaining branches grow into each other at high density. Two reasons: a compact canopy keeps flowers within arm’s reach for hand pollination, and where two cultivars or species share a tree, intergrown branches place pollen and receptive flowers side by side.
One detail worth knowing: if you strip leaves off by hand at the base of a branch, a new shoot may push from that point. Useful when you want branching there, a nuisance when you do not — so pull leaves deliberately.
Size and growth rate
Annona reaches 2-10 m (6-30 ft). Growth is medium to fast, and faster still in a genuinely tropical climate or with generous feeding, so a tree left alone will pass out of reach within a few seasons. Given how much of your crop depends on hand pollination, height is not an asset here.
Light: full sun gives the best growth and the heaviest crop. The tree will tolerate half shade but will not perform as well in it.
Pests and diseases
The list is mostly sap feeders, plus one serious wood pest: aphids, scales, mealybugs, leafhoppers, whiteflies, mites and borers.
- Sap feeders weaken new growth and coat leaves in honeydew, on which sooty mould then grows. Watch for ants — they farm aphids, scales and mealybugs and defend them from predators, so controlling ants is part of controlling the insects.
- Mites are easy to miss. Look for fine stippling and dull, bronzed leaves in hot, dry spells.
- Borers tunnel inside the wood where sprays cannot follow. Holes in the trunk are the warning sign, and a reason to inspect any tree carefully before buying it.
Because you are deliberately growing a dense canopy, routine inspection matters more than it would on an open tree — problems hide in there.
Harvest and uses
An Annona normally begins bearing 2 to 4 years after planting, and fruit follows from summer into autumn.
The fruit rind varies a great deal across the genus: sometimes it carries scale-like flakes that stand out from the surface, sometimes bumps, sometimes short fleshy spines. Inside, the flesh is white to yellowish and soft.
Most of it is eaten raw, which is where the flavour is at its best. A heavy crop ripens fast and does not keep, so the standard answers to a glut are juice, jam and cakes — all of which suit soft, quickly perishable fruit.
For the full plant profile see our Annona tree growing page.
