Date: Fri 08-Dec-1995

Publication: Bee

Author: SHANNO

Illustration: C

Location: B-10

Quick Words:

Bleach-apple-tree-Orchard

Full Text:

(Suburban Gardener, caring for apple trees in winter, 12/8/95)

Suburban Gardener-

The Orchard In Winter

By Anthony C. Bleach

Many of us have old, neglected apple trees that are impressive enough to

cherish and may need some judicious pruning "to improve their health, prolong

their lives and encourage them to bear, and as long as the trunk is not hollow

or many of the limbs lost to breakage or disease, they may be worth saving,"

as Barbara Damrosch writes in her unique Garden Primer .

The best way to restore an old tree is to do it in stages. The first year,

remove any dead branches, water spouts (which are thin whips coming straight

up from the branches) and suckers, which come up from the roots. The second

year, remove the worst of the crossing, or inward growing, branches and some

of the top branches to let in more light. The third year, complete the job to

let more light in, saving healthy, outward springing branches.

Fruit trees have their individual optimal soil pH and fertility range.

Consider soil testing for pH and nutrient levels now. Once fruits are planted

it makes little difference when fertilizers are applied. Phosphorus,

potassium, magnesium and boron can be applied whenever soil analysis shows

they are needed, except on frozen ground. Nitrogen should be applied in the

spring as it is easily leached out of the root zone.

Generally, fruit-growing soils should be brought to medium or high levels of

calcium, magnesium and potassium. Blueberries do best when soil pH is 4.5 to

4.8. For soils between pH 4.8 and 5.5, ammonium sulfate used as the nitrogen

fertilizer will satisfactorily lower pH.

You can also dig in compost or decaying wood chips. For soils with a pH above

5.5 - probable in most cultivated gardens - use aluminum sulfate to acidify

the soil.

Rake up leaves, which will usually be infected by disease spores. Next spring,

with the right weather conditions, the disease organisms may attack the new

growth. You will see the disease symptoms on the tree later in the growing

season. Apple scab is typically perpetuated in this way. Removing the leaf

debris can help reduce insect populations as well.

Both diseases and insects also overwinter in fallen fruit. If we get days when

the temperature climbs to a balmy 40 degrees, you could celebrate by giving

your trees a dormant oil spray. This will control such insect pests as scale,

leaf rollers, spider mites, aphids and even the fungus, apple scab.

Split bark is a common form of winter injury. On a sunny day, the bark will

warm unevenly. The bark with a southern exposure may be as much as 30 degrees

warmer than the northern side of the tree trunk. The tender bark may split as

the temperature drops at night. To prevent tree bark from splitting, spread a

light coat of exterior white latex paint on the lower 24 to 35 inches. The

painted surface will reflect the sun's rays away from the trunk, reducing the

fluctuation of the bark temperature. Never use oil-based paint, however, as it

will cause serious tissue damage. Repeat the job every two years.

Mice and voles may nest around fruit trees in winter, gnaw the bark of the

trunk or chew the roots. Rabbits can also do this. To reduce their damage,

wrap a piece of quarter- or half-inch mesh hardware cloth around the trunk.

This guard should be 24 inches high and be buried three to four inches below

the soil surface.

(Much of the information for this column came from HortImpact, a newsletter

for home gardeners published by the University of Connecticut. Anthony C.

Bleach organizes and teaches the horticulture degree programs at Naugatuck

Valley Community-Technical College.)