Nectarine

Feed between bloom and petal fall, then again two months later

Between bloom and petal fall, spread a complete fertilizer such as 10-10-10 or 12-4-8 out under the canopy at 1 cup per year of tree age, to a maximum of 10 cups for a mature tree. Repeat about two months later. After the fruit is picked, follow with 1 cup of calcium nitrate per year of tree age, to a maximum of 4 cups. Base the rate on a soil test and on how much shoot growth the tree made last year, and take a leaf sample in July if a bearing tree looks off. The tree is spending stored reserves on flowers and the first flush of shoots right now, and nitrogen taken up in that window goes into the fruit-bearing wood rather than into soft late growth.

⚠ Measure by the cup, not the pound - a cup of granular 10-10-10 is about half a pound, so a ten-pound dose on a mature tree is roughly double the extension rate and will push soft growth or burn roots. Do not fertilize after mid-August; late nitrogen pushes tender growth that will not harden off before winter.

Thin nectarine fruitletsMay – Jun

Thin peaches and nectarines by hand when fruit is small, leaving roughly 6-8 inches between fruit. Thinning early prevents small fruit and reduces limb breakage.

Prune nectarine like peachFeb – Mar

Maintain an open-center tree, remove upright water sprouts and dead wood, and head back fruiting shoots to outward laterals. Nectarines bear on one-year wood and need annual pruning to keep fruiting wood close to the scaffold limbs.

⚠ Avoid heavy pruning during wet freezing weather.

Strip every mummy and cut out the blighted twigs

After the last fruit is picked, pull off every shriveled mummy still hanging in the tree, rake up the fallen and rotted fruit, and cut out twigs with sunken cankers or dead blossom spurs. Destroy the lot - do not compost it at the base of the tree. Monilinia overwinters in exactly those mummies and cankered twigs, and they are the spore source that infects next spring's blossoms and next summer's ripening fruit. Removing them is the cheapest brown rot control there is, and it lowers how much you have to spray next year.

Peach leaf curl: one dormant copper spray, before buds swell

Once every leaf has dropped, spray the whole tree - every twig, bud and branch - with a fixed copper fungicide such as copper octanoate or copper ammonium, or with chlorothalonil as a non-copper rotation. Add 1 percent horticultural oil to a copper spray to help it stick. In high-rainfall areas repeat in late winter before the buds swell. Taphrina deformans overwinters as a film of spores on the bud scales and twigs and infects the new leaves as they push, needing only wetness for about 12 hours below 61F. The fungus is inside the leaf before you ever see the puckered red tissue, so the only spray that works is the one already on the bark when the bud opens.

⚠ Do not apply copper once bloom has begun. Fungicides applied during the growing season will not work and spraying after curled leaves appear cannot reverse the damage - wait for the next dormant season.

Delayed-dormant oil at bud swell for scale, mites and twig borer

When the buds have begun to swell but before any flower opens, spray horticultural oil, with spinosad added if peach twig borer has damaged shoots in past years. Cover the rough bark and crotches where the larvae shelter. Peach twig borer overwinters as a tiny larva in a hibernaculum tucked in the bark and crawls out just before and during bloom to tunnel into new shoots. Oil at bud swell smothers those larvae along with overwintering mites and scale, before the tree is in flower and off limits to spraying.

⚠ Apply before bud break, never once flowers are open - spinosad is toxic to bees for several hours after application while it is still wet.

Peach twig borer: spinosad at petal fall, late in the day

As the last petals drop, spray spinosad to cover the shoot tips where the young larvae are boring in. Apply in the late afternoon or evening. The overwintered larvae leave their bark shelters during bloom and petal fall and burrow into the tender new shoots, flagging and killing them; once they are inside the shoot no spray reaches them, so petal fall is the one window when the larvae are exposed and the bees have gone.

⚠ Spinosad is toxic to honey bees for several hours after application until the spray dries - apply in the late afternoon when bees are no longer foraging, and never during bloom.

Brown rot: start cover sprays about three weeks before harvest

When the fruit first takes on color, roughly three weeks out from picking, begin fungicide sprays on a 7 to 10 day schedule and continue to harvest. Captan 50WP, myclobutanil and sulfur are the home-garden options; rotate between them rather than leaning on one. Early-ripening varieties need fewer rounds than late ones. The two to four weeks before harvest are the most susceptible period of the whole season - as sugar rises the fruit loses its resistance, and Monilinia spores blowing off overwintered mummies turn a bruised or insect-punctured fruit to rot in two to five days.

⚠ Captan has a 0-day PHI and a 24-hour re-entry interval on peach and nectarine. These fungicides are preventive only - they cannot protect fruit that is already cracked or insect-injured. Do not spray sulfur above 90F or it will burn the foliage.

Pick firm-ripe, and read the background color not the blush

Ignore the red blush and look at the background skin between it - pick when that ground color has turned from green to yellow, or to a pale greenish-white on white-fleshed varieties. Take the fruit while it is still firm rather than soft, and taste one to calibrate. Clingstone types come away from the spur easily when ready. The red blush colors up long before the fruit is ripe and tells you nothing; the background color is what tracks actual maturity, and fruit left until soft on the tree bruises on the way to the kitchen and invites brown rot.