It's time to prune - Correctly

Pruning trees is the kind of gardening that gets popular every spring, with sometimes good - and sometimes less good results.

The time to prune for Northern Nevadans is right now, early spring. Some trees, such as birch or maple, bleed if pruned in early spring, but they suffer no damage.

"No branch should be removed without a reason," gardening author Dick Post told an anxious group of listeners at the Greenhouse Garden Center recently.

Brandishing a pair of hand shears, he cited some of the good reasons for pruning:

• To remove dead branches (but there's a trick to this)

• To remove crowded or rubbing branches

• To encourage trees to develop a natural form and character.

• To eliminate hazards, such as a branch rubbing against an electrical power line

• To let more light get to the ground below or into the crown.

Older, mature trees, need little pruning, except for a problem such as correcting growth. And the application of wound dressings, once thought to accelerate wood closures and protect from insects and decay, are no longer thought to be effective.

Pruning a limb should be done at the branch swelling, or "branch collar," which contains trunk tissue. If the branch is heavy, remove parts of it away from the trunk, Post said. A cut into the underside of the offending limb up from the final cut will guard against tearing of bark back to the trunk when the limb falls.

Post, whose book "Nevada Gardener's Guide," has just been reissued (Cool Springs Press, $24.99), demonstrated the variety of tools used in pruning, ranging from small hand shears to clippers and clippers and saws on long poles.

There are "Two kinds of hand shears," he explained, brandishing them. "One has a single blade that moves against an anvil. The other, a pruning shear, has two curved, interactive blades and is the best choice." (Cut from below for ease of job and a close cut.)

Post had a display of publications for the audience. One of the best was from The National Arbor Day Foundation, "How to Prune Young Shade Trees." Here are some of the pamphlet's suggestions:

• Prune early in a tree's life when cuts will be small.

• Check limbs from the top down and work downward.

• Identify the best leader branches (which lead upward) and lateral branches before pruning.

• Keep tools sharp.

• Consider safety first. For high branches, use a pole pruner. Major jobs should be left to the pros.

• When pruning from the trunk or larger limb, branches that are too small to have formed a collar (the swollen area at the base) should be cut closely. Do not leave a protruding stub.

• When shortening a small branch, make the cut at a lateral bud or another lateral branch. Go for a bud that will grow a branch in an outward direction.

At about 5 to 7 years old, lower limbs are best pruned. Note: Lower limbs will not move up as the tree grows. If the center of a lower limb is at 5 feet, it will always be at 5 feet - thicker and stronger, yes, but not higher.

Pruning flowers, bushes and all the rest of garden beauty is another topic and one we'll look at soon. Meanwhile, take care reaching for that topmost limb!

Terms to know

Crown cleaning: The removal of dead, dying, crowded, weakly attached and low-vigor branches form the crown.

Crown thinning: The selective removal of branches to increase light and air penetration through the crown.

Crown raising: Removes lower branches to offer clearance.

Crown reduction: Reduces the size of the tree.

Pruning tips

• Before pruning, be certain you know the species and cultivar of the plant.

• Try to imitate the plant's natural shape.

• When in doubt, prune less, or call in an expert.

• Start by removing dead wood and damaged branches. This may be all that is needed.

• Remove no more than one-third of woody stems per year.

• Never "top" (cut the top out of) a shade or ornamental tree.