Care and Protection for Dormant Trees
Trees in fall are in a state of serious change and
reorganization. The tree is becoming dormant. A tree heading toward
winter will sense the changing temperature and light and obey the
dormancy controls built into the leaf. The mechanisms, called
"senescence", tells a tree to close down for coming winter.
Trees may look inactive going into winter but the fact is they
continue to regulate their metabolism and only slow down some
physiological activities. This decrease in
photosynthesis and transpiration begins
a tree's dormant phase. Trees still continue to slowly grow roots,
respire and take in water and nutrients.
Winter is a difficult time for a tree. A dormant tree still
needs to be protected (winterized) to remain healthy and free from
diseases and insects. Bad news is, winter weather encourages
destructive pests to snuggle in and wait for spring to revive their
destructive lifecycles. Small investments in your time can pay off
big come spring.
Pruning -
Prune dead, diseased and crossing branches in late fall. This
will form and strengthen the tree, encourages new strong growth in
the spring, minimizes future
storm damage and protects against
overwintering disease and insects. Remember that dormant pruning
has another benefit - it is easier to do during winter dormancy
than in spring.
Correct structurally weak branches and limbs. Remove all
deadwood that is clearly visible. Properly prune branches that can
touch the ground when loaded with rain and snow. Foliage and
branches that are in contact with soil invite undesirable pests and
other problems. Remove damaged and declining twigs, branches, and
bark or any new sprouts that have grown at the tree base, or along
stems and branches.
Mulch and Aerate-
Young trees are especially vulnerable to fluctuations of
temperature and moisture and need mulching protection. Mulch is
good insurance that both conditions will be evenly managed during
cold and drought. Mulching is a good practice for both dormant and
full-growing, vegetative trees.
Spread a thin layer of composted organic mulch to cover the soil
several inches deep. Cover an area at least as large as the branch
spread. In addition to protecting feeder roots, mulch also recycles
nutrients directly to these roots.
Aerate soils and compacted mulch if they are water-logged or
poorly drained. Saturated and dense soil can suffocate roots. It is
critical not to damage
tree roots in the soil as you do this
so work only on those few inches at the surface crust.
Fertilize and Water -
Fertilize by top dressing over the mulch with a balanced
fertilizer if the essential elements are in short supply within the
soil. Be sure to use nitrogen lightly, especially under large,
mature trees and around newly planted trees. You do not want a
vegetative "flush" of growth during late fall periods of warming.
Large applications of nitrogen cause this growth.
Dry spells in winter or hot daytime temperatures will desiccate
a tree very quickly. Watering may be needed where soils are cool
but not frozen, and there has been little precipitation. Winter
droughts need treatment with water the same as summer droughts,
except it is much easier to over-water in winter.
Dormant Spray -
A dormant spray may be a good idea for deciduous trees,
ornamentals, fruit trees and shrubs. But remember not to spray
until after you prune. Obviously, you will lose much of your effort
and expense if you cut off treated limbs.
Choice of chemicals is important. Dormant sprays include lime,
copper and sulfur combinations to kill overwintering
microorganisms. Dormant oil controls insects and their eggs. You
just may need several types of sprays and oils to be effective.
Avoid spraying any of this material in the hot sun as it can
damage dormant buds. Get specific chemical recommendations from you
local county extension agent.
Written by:
Chris Holmes
Twin Oak Tree Care LLC
