Why are my peaches falling off the tree early?

Finding small unripe peaches on the ground beneath your tree is worrying, but it is not always a sign of trouble. Peaches and nectarines drop excess fruitlets as part of their natural development. Knowing the difference between a normal thinning event and stress-driven drop is the first step to responding correctly.

Natural June drop

In late May and June, peach and nectarine trees spontaneously shed a proportion of their immature fruitlets. This is the tree's mechanism for regulating crop load — it drops the weaker fruit it cannot support to maturity. You may find a carpet of marble-sized peaches under the tree over a week or two. This is perfectly normal and requires no action. After it is complete, you can carry out additional hand thinning if the remaining fruitlets are still crowded.

Drought stress after fruit set

Peaches are very sensitive to water stress during the period from fruit set to the first rapid-growth phase in late May and June. If the soil dries out at this stage, the tree jettisons fruitlets it can no longer support. Maintain steady soil moisture from blossom time until harvest. Apply a thick mulch of composted bark or wood chips 10 cm deep around the root zone — keeping mulch clear of the trunk — to conserve moisture and moderate soil temperature.

Erratic watering causing irregular drop

Alternating dry spells and heavy watering creates irregular cell development in the fruit — the same mechanism that causes fruit cracking. The resulting physiological stress triggers early drop of fruitlets that have begun to crack or whose vascular connections have been disrupted. Water consistently: deeply but infrequently, allowing the top 5 cm of soil to dry between irrigations but never letting the root zone dry completely.

Brown rot infection of young fruit

The fungus Monilinia laxa (brown rot) can infect young fruitlets through the flower or through skin wounds, causing them to shrivel, turn brown, and fall. If dropped fruitlets are brown and mummified rather than green and firm, brown rot is the likely cause. Remove and dispose of all affected fruit — never leave mummified fruit on the ground or on the tree. A preventive copper spray at petal fall helps reduce inoculum levels.

Pest damage

Codling moth and plum moth larvae can bore into young peach fruitlets, causing them to fall early. If you find a small entry hole with a sawdust-like frass plug in dropped fruit, caterpillar damage is the cause. Pheromone traps for codling moth, erected from late May, help monitor and reduce populations. Remove all fallen fruit promptly so larvae cannot pupate in the soil beneath the tree.