Frost Protection

Protecting fruit trees from frost is difficult in the backyard. Anti-smog restrictions prohibit use of smudge pots or similar protection.

Choose the most frost-free site available before planting. Record the minimum temperatures in available sites for at least a year in critical areas. Avoid planting in draws or basins where cold air settles. Higher elevations are usually best, but windswept knolls should be avoided.

Covering trees with tarpaulins or other material to prevent radiation cooling is one way of protecting them. However, some framework is usually necessary to avoid tree damage. It is cumbersome to cover large trees, and the cover must be left on until air temperature is safely above freezing and then removed before damaging heat is built up. Hence, covering is usually impractical except for small trees.

Low volume sprinkling can be used for frost control. Pruning must be altered to give a heavy, stiff framework to hold the ice load from all-night sprinkling. Protection depends on a continuous film of unfrozen water which releases heat for bud protection. Sprinkling must be continued until air temperature is well above freezing or the night's effort may be lost.

Don't try growing stone fruits unless you provide for adequate pest control. You need spray equipment capable of reaching the tops of mature trees, or you need to be able to hire a custom spraying service when required.

Obtain and follow carefully the pest control calendar from your county Extension office. Timing of sprays is extremely important. Use only currently recommended materials at the rates specified.

Brown rot, caused by Monilinia spp., destroys more ripening fruit than any other pest. This is particularly serious in areas where it rains during and just before harvest. Removal of rotting fruit and "mummies" from the trees will help control spread of the fungus.

Scab, leaf curl, and cherry leafspot usually are not troublesome if trees are sprayed regularly. Bacterial leaf spot is not adequately controlled by spraying in extremely sandy soils of the Eastern United States resistant varieties should be planted.

It's tempting to want to leave all the fruit on a peach tree. By thinning the peaches, those left on tree will be larger.

Several virus and virus-like diseases can spread unchecked unless diseased trees are recognized and removed. They will not recover, and endanger nearby trees.

Precise timing of sprays should give adequate control of insects. However, missed sprays can result in wormy fruit, dead "flags" in the terminal growth, girdling of trunks by borers, or leaf damage by aphids and mites.

Protecting trunks from mice and rabbits with wire screens or plastic wrap-grounds may be necessary on trees growing near forests. Covering ripening fruit with netting is often the only way to protect it from birds and squirrels.

Fruit Thinning

Adequate dormant pruning removes a large number of flower buds. Pruning is the only practical thinning method for cherries, and can do a partial thinning in the other stone fruits. Heavy pruning may reduce the number of buds too drastically if later frosts kill additional fruit buds.

Additional thinning usually is needed after fruits have started development. Trees overloaded with fruit must have the crop thinned out to produce fruit of adequate size and good quality, and to prevent limb breakage.

Peaches, nectarines, plums, and apricots should be spaced 6 to 8 inches apart. Early ripening varieties need the greater spacing, and must be thinned early to give large fruit. Later varieties can be thinned at the pit-hardening stage without much loss in final size.

The advantage of homegrown fruit is that the best quality possible can be attained by ripening it on the tree. Most fruit for commercial use must be picked three to seven days before soft ripeness to withstand handling and shipping.

Ripeness can be estimated by the disappearance of green and the development of yellow undercolor. Pressing the pads of your fingers against a fruit in your cupped hands will indicate softening of the fruit without damaging it. The fruit should be harvested by this same method, adding a slight twist of the wrist to loosen the fruit from its stem.

Pick the fruit into shallow containers to keep bruising at a minimum. Handle the fruit gently in moving and transporting it.

Fruit which will be used within a short time need not be refrigerated. It will attain its best quality in relatively warm storage.

Most varieties of fruit can be held in refrigerated storage for two to three weeks without excessive loss of quality. Longer storage usually results in internal breakdown of the flesh.

Stored fruit should be checked regularly for rotting or internal breakdown. Use the fruit as close to its prime quality as possible.