Pests and Diseases That Plague Cherries
Kelly Givens explains some of the problems that can affect cherries and how to protect the harvest.
Kelly Givens shares information on the diseases, pests and weather conditions that can adversely affect cherry trees. Early spring frosts can damage cherry blooms, but an old real estate adage ("location, location, location") can help keep Jack Frost's dangers at bay. We also lean how to minimize bird damage to a cherry crop, discover the benefits of good sanitation practices in an orchard and find out the secret to harvesting cherries at their peak of ripeness.
As with all fruit crops, it's important to control insects and diseases on cherry trees. Selecting disease-resistant cultivars will help minimize potential problems, but you'll still need to monitor your trees and keep an eye out for potential problems.
Common problems with cherry trees include leaf spot, seen here, bacterial canker and brown spot. Remove any signs of diseased foliage, dipping your pruners in full-strength rubbing alcohol or a 10 percent bleach solution between cuts and taking the diseased foliage out of the garden area for disposal.
In many areas of the country, you'll need to stick to a spray schedule in order to get a good harvest. Spray schedules for insecticides and fungicides are available from your local cooperative extension service.
Birds love sweet cherries; the only real solution is bird netting. Cover the trees with the netting when the cherries start to ripen, and secure the netting to the ground. Birds can also be a problem on tart cherries, but usually not to the same degree as with sweets.
A late spring frost can wipe out the harvest for a year. Where you plant cherry trees may make a difference. If possible, plant trees on higher ground, since frost settles in low-lying areas. Sometimes an elevation difference of only several feet can affect the temperature by 5 or 10 degrees Fahrenheit.
To protect against a frost that's predicted after fruit-bud set, put lightweight plastic or fabric over the tree to form a tent and add a heat source in the form of a light bulb or string of holiday lights. For safety's sake, use only UL-approved outdoor lighting and extension cords, and make sure that the light source does not touch the fabric and is not too close to the tree trunk or branch, where it might burn.
- Cherries are among the earliest fruits for harvesting, being ready to harvest in late spring or early summer.
- There are some crops, such as apples, in which sugars will develop in the fruit after it's harvested. But cherries don't get any sweeter after they leave the tree, so if you pick too early, you sacrifice some of the sweetness.
- Cherries increase in size until they're ripe. Sweet cherries also become firm when ripe.
- You can taste cherries to test for ripeness, or test by trying to harvest a few. When they're really ready, they'll be easy to pick. If they're not quite ready, they'll be a little harder to pull off the tree.
- Sweet cherries are typically picked stem and all. They have a relatively thick skin, which helps protect them and allows them to last for a week or two after being picked. Tart cherries are usually picked without their stems. They have a thin skin and bruise easily and are more fragile than sweet cherries.