Apricot

Thin the young fruit to one every 4 to 6 inches

When the fruits are grape-sized, thin them to one fruit every 4 to 6 inches along the branch, taking off the smallest and any that are doubled or touching. Apricots habitually set far more fruit than they can fill, and a tree left unthinned ripens a crop of small stone-heavy fruit while spending the reserves it needs for next year's buds and for wood strong enough to hold the load.

Prune to an open vase while the tree is still dormant

Prune in late winter, while the tree is still fully dormant and before the buds swell - in warm zones that can be January, in cold zones March, so watch the buds rather than the calendar. Train young trees to an open vase by keeping 3 to 4 evenly spaced scaffold branches that start 18 to 24 inches above the ground and cutting out the central stem. On an established tree, start with any dead, diseased, or damaged wood, then remove about 25 percent of the branches to open the canopy to light. Apricots fruit on short spurs that stay productive for 3 to 5 years, so the goal is light reaching the inside of the tree to keep those spurs alive and renewing rather than a shell of bearing wood on the outside.

⚠ Because the spurs bear for 3 to 5 years, cutting out too much older wood removes the crop - take the 25 percent from crowding and shading branches, not from healthy spur wood. Apricot breaks dormancy earlier than any other stone fruit; if buds have already swollen you are late, so prune and stop rather than working into open bloom.

Strip the mummies and cut out the blighted twigs

Remove fruit mummies from the tree immediately after harvest, clear the fallen fruit from the ground beneath it, and cut out twigs killed by blossom blight along with any branches carrying cankers. Compost or bury the infected fruit rather than leaving it at the base of the tree. Every mummy and canker is where Monilinia spends the winter, and those are the spores that will hit next spring's blossoms - clearing them is the single cheapest way to cut how much you have to spray next year.

San Jose scale: horticultural oil at delayed dormant

As buds swell and show their first green but before any blossoms open, spray horticultural oil, covering bark, crotches, and the undersides of scaffold limbs until it drips. San Jose scale overwinters on the bark under a waxy armor that shrugs off most materials, and oil kills by smothering, so it only works while the insects are exposed and the tree has no open flowers to injure.

⚠ Oil must go on before bloom - never spray oil onto open blossoms, both because it injures the flowers and because bees are foraging in them.

Brown rot blossom blight: fungicide as the flowers open

Begin fungicide applications when the blossoms first begin to open, using myclobutanil, propiconazole, chlorothalonil, captan, or sulfur, and repeat on the label's interval until petal fall. Wet, mild weather during bloom is what makes the extra applications necessary. Monilinia overwinters in mummified fruit and cankered twigs, and its spores infect through the open flower, then grow down the flower stem into the spur and kill it - so a blossom missed now becomes a twig canker that seeds the whole orchard next spring.

⚠ These are fungicides and are appropriate during bloom, but do not tank-mix or follow with an insecticide while flowers are open - bees are foraging. Chlorothalonil is for blossom blight only and is not used for the later fruit rot sprays.

Coryneum blight: spray just after the petals drop

Apply a fungicide for Coryneum blight, also called shot hole, just after petal fall as the young leaves are expanding. USU pairs this with a second application in autumn at 50 percent leaf drop; the spring spray alone is only half the program, so plan on both. The shot hole fungus survives inside infected buds and on twigs, and its spores are splashed onto the new leaves and fruit by spring rain - the tissue is only vulnerable while it is young, which is why the timing hangs on petal fall rather than a date.

⚠ Time this to petal fall because that is when the new tissue is susceptible, not because earlier spraying is forbidden - the pre-bloom oil and the bloom fungicide are both correct in their own windows. Do not substitute an insecticide into this slot while any blossoms remain open. Read the label's pre-harvest interval for your product before applying.

Brown rot fruit rot: start sprays as the fruit colors up

Begin fungicide sprays 2 to 3 weeks before harvest as the fruit begins to ripen, using myclobutanil, propiconazole, or captan, and repeat on the label's interval until harvest. Ripening apricots go from resistant to highly susceptible as their sugars rise, and a single infected fruit will sporulate and rot the ones touching it, so the protection has to be on the fruit before the ripening window opens.

⚠ Chlorothalonil must not be used for fruit rot - it is a blossom blight material only on stone fruit. Every one of these sprays lands inside the pre-harvest interval, so read the label's PHI in days for your product and do not pick before it has elapsed.

Protect apricot bloom from frostMar – Apr

Watch forecasts during bloom and cover small trees before freezing nights, extending fabric to the ground and removing it in the morning. Apricots bloom early, so spring freezes can erase the crop even when the tree survives.

⚠ Do not let plastic or fabric crush blossoms; uncover for pollinators after the cold night.

Pick when the fruit softens and the green is gone

Harvest when the skin has turned fully from green to yellow, orange, or red and the fruit gives slightly to gentle pressure. Go over the tree repeatedly and pick all fruit as it ripens rather than stripping it at once. Apricots ripen unevenly across a tree and lose flavor if picked while still green-shouldered, and any overripe fruit left hanging becomes the brown rot inoculum for next season.