Gadenin日本語Get the appThe two fruit drops
A persimmon sheds fruit in early summer, a few weeks after bloom, and it sheds a lot. Marble-sized fruit yellows at the stalk end and falls in numbers that alarm anyone seeing it for the first time. This is the tree correcting itself: it sets far more fruit than it can carry on brittle wood, and it dumps everything that is poorly pollinated, shaded or simply surplus. A young tree may drop the entire crop this way and that is still within normal behavior.
The second drop is different and it is a message. It comes later, on fruit that is already walnut-sized or bigger, and it follows a check to the tree. The usual cause is water, specifically a dry spell followed by a soaking, which is far worse than steady dryness. Heavy nitrogen, a sudden hot spell, root disturbance from digging near the tree, or a heavy crop left unthinned all produce the same result.
Telling them apart is easy once you know the timing and the size. Early, tiny, and everywhere on the tree means the natural drop and needs no action. Later, larger, and following a change in conditions means you should look at your watering. Note the date each drop begins and roughly how heavy it is, because two or three years of that record tells you whether your tree drops on a schedule or only in dry years.
| Drop | Timing | Fruit size | Cause | What to do |
|---|---|---|---|---|
| Natural drop | A few weeks after bloom | Marble or smaller | Self-thinning, poor pollination | Nothing. Let it happen |
| Stress drop | Mid to late summer | Walnut-sized or larger | Dry spell then heavy water | Even out watering, mulch |
| Nitrogen drop | Any time in summer | Any size, with lush shoots | Too much feed | Stop feeding for a year |
| Pre-harvest drop | Weeks before ripening | Full size, hard | Heat spike or drought | Deep water, shade the trunk |
Watering: steadiness beats volume
An established persimmon is reasonably drought tolerant and will survive a dry summer without any help. It will not carry a crop through one. The tree responds to swings in soil moisture rather than to dryness itself, so the aim is a soil that never gets truly dry and never gets soaked, right through from bloom to harvest.
Water deeply and infrequently. Put on enough to wet the soil twelve inches (30 cm) down, then leave it alone until the top three inches (8 cm) has dried. Check by pushing a finger in rather than by looking at the surface. A slow soak over an hour at the edge of the canopy, where the working roots are, does more than ten minutes with a hose at the trunk.
The critical window runs from the end of the natural drop until the fruit begins to color. That is when the fruit is sizing and when a drought will cost you the crop rather than just the growth. Once the fruit has colored, ease off; the last few weeks want steady moisture, not generous watering, and a flood of water into ripening fruit encourages splitting.
A mulch two to three inches (5-8 cm) deep over the whole root area, kept clear of the trunk, does more for moisture steadiness than any watering schedule. It also stops the surface roots baking, and persimmon roots run shallow and wide.
Feeding: much less than you expect
This is a tree that is easy to overfeed and hard to underfeed. Excess nitrogen produces long soft shoots, dark floppy leaves and a wave of fruit drop, and it delays coloring in autumn so that non-astringent fruit never fully loses its tannin. Many persimmons growing in a mulched garden bed need no fertilizer at all.
Judge by extension growth, which is how much each shoot lengthened over the season. Measure a few shoots at leaf fall. Twelve to eighteen inches (30-45 cm) on a young tree, and eight to twelve inches (20-30 cm) on a bearing tree, is right. More than that and you are feeding too much. Under six inches (15 cm) with pale leaves and the tree is genuinely short.
If you do feed, do it once, as buds swell in spring, with a balanced fertilizer spread over the whole root area and watered in. Never feed after midsummer: late nitrogen pushes soft growth that will not harden before the first hard frost, and on brittle-wooded persimmon that soft growth is exactly what breaks.
Yellowing between the veins on young leaves, worst at the shoot tips, is usually iron shortage caused by wet or alkaline soil rather than by a lack of fertilizer. Fix the drainage before you reach for anything else.
Thinning and propping the brittle branches
Persimmon wood is genuinely brittle. It is not flexible timber that bends under load; it splits with a crack, usually at a narrow crotch, and usually in the week before harvest when the fruit is at its heaviest. A single split limb can take a third of the tree with it and leaves a wound that never closes properly. Thinning the crop and supporting the heaviest limbs are not optional refinements on this tree.
Thin after the natural drop has finished, not before, or you will thin fruit the tree was going to shed anyway. The tree also tends to bear heavily one year and barely at all the next, and thinning is the most effective thing you can do to even that out, because a light crop this year is what lets the tree set fruit buds for next year.
- Wait until the early drop stops Give it a week with no fruit on the ground. Then you are working with the crop the tree actually intends to carry.
- Thin to one fruit every six inches Leave a single fruit roughly every six inches (15 cm) of fruiting shoot, and remove every cluster down to one. Take off small, marked and badly placed fruit first. Snip the stalk rather than pulling, which tears the shoot.
- Strip the tips of long limbs Fruit at the far end of a branch has the most leverage. Removing the outermost one or two fruits from each long limb reduces the breaking force far more than the same number taken near the trunk.
- Prop before you think you need to Put a padded forked prop under any limb that has begun to bend, well before harvest. Once a limb has taken a set, propping only stops it getting worse. Pad the contact point so the prop does not rub the bark.
- Take the crop off a young tree For the first two or three cropping years, remove most of the fruit. A young persimmon carrying a full crop bends its scaffold limbs permanently downward and never builds a proper frame.
What to write down
Four notes a year make the difference between guessing and knowing. Record the date the tree came into full bloom, the date the early drop started and roughly how heavy it was, the date you thinned and how many fruit you left, and the date of the first pick.
Add the extension growth measured at leaf fall and a rough count of the crop. After three seasons you will be able to see your own tree's alternate-bearing rhythm, whether your dry-summer years line up with your poor-crop years, and whether the thinning you did actually bought you a crop the following year. None of that is visible from a single season, and no general guide can tell it to you about your particular tree in your particular garden.