Pluot

In late winter, before buds swell, train the tree the way a Japanese plum is trained: an open vase of 3 to 4 main scaffolds starting 24 to 30 inches off the ground, with the central stem removed entirely. On a bearing tree take out roughly 25 percent of the wood, favoring crossing limbs, inward growth and anything dead. Pluots inherit the Japanese plum habit of throwing dense upright growth that shades out its own fruiting wood, and light reaching the interior is what colors and sizes the crop.

While the tree is still dormant or at delayed dormant, from silver tip up to about half-inch green and before any flowers open, cover the trunk, scaffolds and twigs to the drip point with horticultural oil. Pick a dry day above 40F with no freeze in the forecast. San Jose scale spends the winter as an immature nymph sealed under a waxy armor on the bark, and a smothering oil film is what gets through it. This is the moment it works: the scale is resuming development so it is breathing hardest, and there is no foliage yet to shadow the spray and shelter the bark. Aphid and mite eggs on the bark go with it.

When the first blossoms crack open, spray myclobutanil, propiconazole, captan or sulfur, and repeat on the label interval until petal fall. If the bloom period stays wet, hold the 7 to 10 day interval. Monilinia spores land on open flowers and need only a few hours of wetness to infect, three hours at 70F. Blossoms lost now become the twig cankers that seed the fruit rot in summer, so this is the spray that decides the season.

Once frost danger has passed and the fruit has set, pull fruit by hand until what remains stands 4 to 6 inches apart along each branch. Waiting until frost risk is over keeps you from thinning a crop the weather was going to thin for you. Pluots set far heavier than the tree can finish. Left alone, the fruit stays small, the sugars spread thin across too many, and limbs loaded to the tip break or fall into alternate bearing.

As the dried shucks split away from the young fruit, spray esfenvalerate, lambda-cyhalothrin or carbaryl, or azadirachtin for an organic program. Repeat at 7 to 10 day intervals, up to three applications, while the beetles keep coming. Overwintered adults move up into the tree once it hits 70F and cut crescent-shaped scars to lay eggs in fruit barely past the shuck. Each female lays 150 to 200 eggs, and the larvae tunnel the flesh and drop the crop early.

Start spraying myclobutanil, propiconazole or captan 2 to 3 weeks before you expect to pick, and repeat through harvest as the fruit softens. Keep it up on the label interval while the weather stays wet. Ripening fruit turns susceptible as its sugars climb, and a single infected fruit can rot the ones touching it in the cluster and then in the picking basket.

Pick when the ground color has changed and the fruit gives slightly to gentle pressure. Pluots ripen unevenly, so go over the tree several times across a couple of weeks rather than stripping it once. Pluot flavor is built on sugar that only accumulates on the tree, and a fruit picked hard never gets there. Colour change and a slight give are what tell you it is done, not a date. Ripe fruit keeps about three weeks refrigerated, so pick in passes rather than all at once.

After the last pick, walk the tree and pull off every shriveled, hardened fruit still hanging, and rake up what fell during the summer. Get it done before spring bud break, and cut out dead and cankered twigs while you are there. Brown rot overwinters inside those mummies and in infected twigs. They are the spore source that fires at bloom next spring, so the fruit you leave hanging in October is the blossom blight you fight in April.