Why Are My Cherries Cracking and Splitting?

Cherry cracking is one of the most common and frustrating pre-harvest problems in home orchards and commercial cherry growing alike. Fruit that has taken weeks to develop suddenly splits open in the days before picking, becoming immediately prone to mould, spoilage and attack by insects. Understanding why it happens is the first step to preventing it in future seasons.

The mechanism of cracking

As cherries approach ripeness their skin becomes thinner and more tightly stretched over the swelling flesh. If heavy rain or irrigation arrives at this stage, both the skin and the flesh absorb water rapidly, but the flesh swells faster than the rigid skin can accommodate. The skin splits, usually radiating outward from the stem end or around the shoulder of the fruit. The split immediately provides an entry point for brown rot, botrytis and other fungi, and the affected cherries rot within days if not harvested immediately.

Rainfall just before harvest is the main trigger

A dry period during fruit development followed by significant rainfall in the final two to three weeks before harvest is the classic setup for a cracking event. The fruit has been developing slowly in dry conditions, the skin is relatively inelastic, and then a surge of water arrives all at once. There is nothing you can do about rainfall, but you can reduce vulnerability by maintaining more consistent soil moisture throughout the growing season with regular irrigation and deep mulching — this way the fruit is less severely dehydrated when rain arrives.

Choosing crack-resistant varieties

Some cherry varieties have significantly thicker, tougher skins that resist splitting better than others. Varieties bred or selected for resistance include Sweetheart, Penny and Regina. If your current variety is consistently cracking — particularly in wet summers — consider planting a crack-resistant variety to replace or supplement it. Late-season varieties are generally more vulnerable because they ripen when summer storms are more likely.

Covering with rain protection

In small gardens, draping a polythene or purpose-made cherry cover over the tree in the final two to three weeks before harvest is the most reliable way to prevent rain-triggered cracking. The cover only needs to keep rain off the developing fruit — ventilation is important to prevent botrytis under the cover. Remove covers during rain and replace them when it stops, or use covers with ventilation built in.

Harvesting promptly

Once cracking has begun, the only option is to harvest all ripe fruit immediately to salvage as much as possible before moulds take hold. Pick early in the morning when temperatures are coolest and process or refrigerate promptly. Cracked cherries that are otherwise sound can be eaten or processed the same day even if they cannot be stored.