Persimmon

Asian Persimmon

Feed lightly in early spring, and resist the urge to do more

In late winter or very early spring, apply about three-quarters of a pound (roughly 1.5 cups) of 13-13-13 per inch of trunk diameter measured at the soil line, spread under the canopy. Judge whether the tree needs it at all first: if the leaves were not dark green last year and the tree put on less than 10 to 12 inches of shoot growth, it needs feeding. If it is dark green and grew more than that, skip it. Persimmon is a light feeder, and excess nitrogen pushes leafy growth at the expense of fruit and triggers premature fruit drop, so overfeeding costs you the crop you were trying to grow.

American Persimmon (Native)

Feed lightly in spring, if at all

If growth is weak, broadcast a balanced 10-10-10 evenly on the ground beneath the canopy at about a half to one pound per year of the tree's age, capping out around eight to ten pounds on an old tree. Skip the spiked fertilizer stakes. Give a newly planted tree nothing until it has leafed out and is growing. A persimmon pushed too hard drops its fruit, so this is a tree where restraint outyields generosity. Most trees in decent soil, especially ones surrounded by fed lawn, need nothing at all.

Asian Persimmon

Thin to 6 inches within a month of bloom in a heavy year

In a year when the tree sets heavily, thin the young fruit to about 6 inches apart, breaking up any clusters. Do it within a month after bloom, while the fruit is still small. A heavy set makes small, clustered fruit, and it exhausts the tree into alternate bearing, where this year's glut buys next year's blank. Thinning early, while the fruit is still cheap for the tree to drop, is what resets that cycle.

⚠ Thinning also protects brittle persimmon limbs, which break under a clustered crop load.

Asian Persimmon

Winter pruning: open the tree, but keep the branch tips

Prune while the tree is dormant. Take out dead, diseased, and crossing limbs, branches bent to the ground, and spindly wood that would snap under a load of fruit. Open the canopy by removing a few whole old branches and heading the tallest ones, rather than shearing every branch back to the same length. Prune what remains lightly. Persimmon fruits on new wood and on one-year-old wood, and the buds nearest the branch tips are the most productive, so uniform heading cuts remove next season's crop and provoke a thicket of regrowth at every cut.

⚠ Persimmon wood is brittle. Train wide, nearly horizontal scaffold angles while the tree is young, because narrow crotches split under fruit weight later.

American Persimmon (Native)

Dormant-prune lightly, and make every cut cleanFeb – Mar

While the tree is fully dormant in late winter, take out dead, broken, and crossing wood and train to a modified central leader, which also keeps the tree from getting too tall. Cut back to the branch collar with a clean, smooth cut and leave no stubs. This tree needs little pruning once it reaches bearing size if you set the form early, so resist the urge to cut more. Persimmon wilt spores are wind-borne and a wound is what lets them in — the Forest Service tells you to cover bruises on healthy trees to keep spores out, so every cut is a door. Cutting while the tree is dormant means fewer open wounds standing through the season when the fungus is active.

⚠ Disinfect your saw and loppers between trees. Save any large cut for the dormant season; in the growing season limit yourself to small work like suckers, or to removing diseased wood.

American Persimmon (Native)

Cut root suckers before they become a thicket

Native persimmon throws suckers from its roots, sometimes well out from the trunk. Cut them off at ground level as they appear through the growing season, while they are still soft and small. This tree sprouts vigorously from roots and the stump, and left alone a mature tree turns its own dripline into a thicket that competes with the tree and with everything planted under it.

⚠ Keep the mower and string trimmer away from the trunk while you are down there; bark wounds are the entry point for persimmon wilt.

Asian Persimmon

Check for scale and mealybug on the sticky evidence

Through the growing season, look over twigs and leaf undersides for scale bumps and cottony mealybugs. The tell is honeydew: sticky leaves and trails of ants running the trunk. Banding material and an insect barrier on the trunk help keep ants from farming them. Note what you find so you know whether a dormant oil spray is warranted next winter. Persimmon has few serious pests, so scouting is mostly about catching the two that do turn up, and because scale is far easier to kill with dormant oil in winter than with anything sprayed in season.

American Persimmon (Native)

Watch for persimmon wilt, top down

Walk the tree and look for leaves wilting and dropping while the branches die back from the top down. Cut into a suspect branch and look for dark streaking in the wood. There is no cure, so remove and burn a confirmed infected tree rather than leaving it standing as a spore source. Cephalosporium diospyri plugs the water-conducting wood, and an infected tree lives only one or two years after wilting starts. It is the one disease with real potential to kill a native persimmon.

⚠ Do not chip infected wood into mulch you will spread around other persimmons, and check local burn rules before burning.

American Persimmon (Native)

Gather the girdled twigs off the ground

Once twigs the thickness of a pencil start dropping with a neat, chewed-through cut at one end, rake them up and destroy them by burning, burying, or bagging. Get the ones still hung up in the canopy too. Do this through fall and winter and finish before spring. The female twig girdler girdles the twig on purpose and lays her egg in the part beyond the cut, because her larva cannot develop in healthy sapwood. The grub overwinters in that fallen twig, so hauling the twigs away is what actually breaks the cycle.

⚠ Insecticide is not the answer here; the larvae are sealed inside severed wood where sprays cannot reach them.

American Persimmon (Native)

Clip out fall webworm nests on young trees

Look for silk webs enclosing the leaves at branch ends. Where you can reach them, prune the webbed tips out and drown or bury them. If webs are too many to prune on a small tree, spray Bacillus thuringiensis while the caterpillars are still small, wetting the foliage next to the web rather than the web itself. Webworms colonize branch ends and can genuinely set back a small young tree. On a big established persimmon the feeding lands so close to natural leaf drop that it does not hurt the tree, and the webs are mostly an eyesore.

⚠ Bt kills only leaf-feeding caterpillars and spares the tree's predators and parasites, but it works only on young larvae; spraying the web from outside will not reach them.

Asian Persimmon

Dormant oil for scale, just before bud swell

If scale showed up last season, spray horticultural dormant oil over the trunk, scaffolds, and twigs in late winter, shortly before the buds swell. Cover the bark thoroughly; the oil only works where it lands. Scale overwinters on the bark as immobile, armored insects, and the oil kills by smothering them, which is why it must go on before growth starts and while the insects are still exposed and stationary.

⚠ Apply before bud swell. Oil on opening buds and young foliage risks injury, so a late application is worse than none.

Asian Persimmon

Harvest on color, not on frost, and clip the stem

Pick by color, not by the calendar. Harvest astringent types like Hachiya and Tanenashi once the color has fully developed but while the fruit is still hard, then ripen them soft indoors. Non-astringent types like Fuyu and Jiro are ready to eat firm, once they color up. Cut the fruit from the tree with shears, taking the calyx and a small portion of stem with it, rather than pulling the fruit off. Waiting for frost is folk advice that backfires: frost will ruin immature fruit on the tree, and persimmons lose astringency as they ripen rather than because of a freeze. Pulling fruit tears it loose at the calyx and opens the wound that rots it in storage.

Asian Persimmon

Pull the astringency out of hard-picked fruit

Astringent persimmons picked hard need to soften before they are edible. Left on the counter they will ripen on their own. To hurry it, bury the fruit in uncooked dry rice for 3 to 5 days, or freeze it for 24 hours and then thaw. The pucker is soluble tannin, and it does not wash out or cook out. It only becomes insoluble as the fruit softens, which is why an astringent persimmon eaten firm is inedible and the same fruit eaten soft is not.

American Persimmon (Native)

Pick only when it is jelly-soft, not when the calendar says so

Test by feel, not by date. Take fruit only when it has gone deep orange and squishy-soft, so soft it feels overripe and pulls free with no resistance. The tree ripens unevenly, so pick it over every few days for weeks rather than stripping it once. The fruit is loaded with soluble tannins until it is thoroughly ripe, and it is softening, not frost, that finally binds those tannins up. Ripe fruit often arrives around your first frost, which is how the frost story got started, but a hard persimmon is astringent in any weather.