Fertilizing Cherries

Control grass or other competing vegetation around the tree for the first few years. A heavy mulch from the tree trunk to the tree's dripline helps conserve soil moisture and control weeds. Fertilize each spring until trees start to bear. Once bearing, cherries need little irrigation or fertilizer in most areas.

If you apply nitrogen to bearing trees, wait until after the fruit has been harvested, but apply it no later than midsummer. This will give the tree a boost toward producing plenty of sugars in its leaves to ripen next year's crop. To prepare the tree for winter, it's a good idea to paint tree trunks white or wrap them with white plastic tree guards. Pull mulch away from the trunk and be sure to harden the tree off.

Be on the lookout for problems with pests and diseases. In the southern parts of the tart cherry-growing area, the only worm to infest the fruit is the larva of the plum curculio, which also attacks sweet cherries. The cherry fruit fly may infest sweet cherries and tart cherries are susceptible to black cherry fruit flies. The apple maggot and peach tree borer may also cause problems.

Brown rot and cherry leaf spot affect both tart and sweet cherries. Black knot and powdery mildew are potential problems for some areas.

Prevent birds from decimating your crop with netting, scare tactics, or barrier-type controls.

Harvesting

One mature, standard-size tart or sweet cherry tree will produce 30 to 50 quarts of cherries a year; a dwarf tree, about 10 to 15 quarts. Wait until the cherries turn fully red to harvest them; the sugar content rises dramatically in the last few days of ripening. You'll need to go over the tree every other day for about a week. Pick the fruit with stems attached, but be careful not to tear off the woody fruit spur, which will continue to produce fruit year after year. If you're using a mechanical cherry pitter, pick the cherries by leaving the stems on the trees. Use these cherries up soon after you pick them because they'll leak juice and may spoil if left out. Using a hand-cranked cherry pitter, you can pit a quart of cherries in 10 minutes.

This fungal disease annually poses the greatest disease risk for fruit loss. Environmental conditions during the 2 to 3 week period prior to harvest can determine whether fruit brown rot will be a problem. Occurrence and severity of brown rot is very dependent on stage of fruit ripeness, time of occurrence of moisture, temperature, and a source of inoculum. As the sugar content increases in the fruit, susceptibility to the brown rot fungus increases. Wet, warm conditions with inoculum sources in or near the orchard during this period create a high risk. In contrast, dry, hot weather during this period greatly reduces the risk even if some inoculum is present. The preharvest/harvest period is the time when the DMI fungicides are very effective when used properly.

Gray garden slug. Most slugs in strawberries range in length from 1/2 to 1 1/2 inches (12 - 36 mm).

Damage Slugs damage fruit by eating deep holes into the surface of berries. Slugs that damage straw berries in Illinois in the spring and early summer hatched from eggs deposited in strawberry plantings the previous fall. Conditions that maybe favor egg-laying in the fall include the continuous presence of straw mulches. Slug survival and fruit damage in the spring are greatest in dense, wide rows and when overcast and rainy weather creates continuously moist conditions in strawberry beds.

Control Removal of straw mulch after harvest, summer renovation, and delaying fall mulching as long as is practical are effective steps in reducing slug populations. Slug baits that contain metaldehyde may be used in strawberries only if the baits are applied to the soil surface (and to mulch) and do not contact plants.