Is My Peach Tree Still Dormant?
When peach trees go dormant, they produce growth inhibiting hormones that prevent them from growing or producing leaves and flowers. This keeps the tree from breaking dormancy before spring arrives. Cold weather breaks down the growth inhibiting hormones and allows the tree to break dormancy. The amount of exposure to cold weather required to break dormancy varies, and it’s best to choose a variety suited to winter temperatures in your area. Most peach trees need between 200 and 1,000 hours of winter temperatures below 45 degrees F. (7 C.). The number of hours required is called “chilling hours,” and your local extension agent can tell you how many chilling hours you can expect in your area. Chilling hours don’t have to be consecutive. All of the hours below 45 degrees F. (7 C.) count toward the total unless you have a spell of winter temperatures that are unusually high. Winter temperatures above 65 degrees F. (18 C.) can set the tree back a little.
Wet Conditions and Peach Trees Not Leafing Out
Peach trees may also fail to leaf out due to overly wet conditions over the winter. If a peach tree is late breaking its dormancy in the spring, this may indicate that the tree is developing root rot. If you suspect that this may be the issue, try to alleviate the drainage issue to help the tree recover, but be prepared for the possibility that you will not be able to save the tree as often by the time the peach tree fails to break its dormancy in the spring, root rot has already damaged significant parts of the root system.
When Do Peach Trees Grow Leaves?
After a peach tree has the required number of chilling hours, any spell of warm weather can cause it to leaf out. It may grow leaves in response to a warm spell in winter if it has experienced enough cold weather, so it is important not to choose low chill varieties, which only need 200 to 300 hours of cold temperatures, if you live in an area with a long, cold winter. When peach trees leaf out in response to a brief warm spell in winter, the tree often sustains serious damage when temperatures return to normal. The damage ranges from leaf loss and soft growth to twig or branch dieback. The only thing you can do when a peach tree has no leaves, other than waiting, is remove dead branches and hope for better weather next year.
