Snip and Shape

When is the best time to prune trees?  "Prune them whenever your shears are sharp,” advise old-time gardeners.

If spring was too hectic and summer too hot, autumn is perfect for doing some snipping and shaping.  With trees that bleed profusely in spring, such as maples, birches, beeches and walnuts, there is not a better time to prune than early fall.  Other popular candidates for autumn trims are ashes, honeylocusts, poplars and elms.

Without the right tools you will do more harm than good.  A carpenter’s saw would no more than cut branches than a paper scissors will cut twigs.  Garden centers offer four basic tools needed by the average gardener.  Ordinary pruning shears are fine for branches up to ¾ inch in diameter.  Long-handled lopping shears are effective for limbs between ¾ and 1 ¼ inches thick or for those beyond the reach of hand shears.

For heavier work a crescent-shaped pruning saw is best.  After a big bough is removed, use a hooked pruning knife to smooth rough edges around the resulting wound.  Protect cuts larger than one inch with a coating of tree-wound paint.

Prune a sapling correctly and it will benefit for years, even decades, to come.  For strength and shape, remove upright suckers that appear at the trunk base or along lower branches.  Also remove inconveniently low branches. Where possible, cut off branches that grow at narrow angles to the trunk and retain those that grow more horizontally. 

On trees that normally have a single leader, or main upper stem, trim back any competitors.  Finally, shorten out-of-proportion limbs by cutting back to branches more in keeping with the tree’s natural shape and symmetry.

Older trees occasionally need deadwood and overgrowth cleared away.  Where two branches rub together, inviting injury, eliminate the less attractive one.  Also remove any inward growing branches.  One rule holds for all pruning: do not leave unsightly stubs.  Always cut as close as possible to the source branch or trunk. With large or heavy limbs use the following four cut technique.

With a pruning saw make a “safety” cut on the underside of the branch about two feet from the trunk.  It will prevent bark and wood from tearing beyond this point.  Stop sawing the branch or whenever the saw binds.

Remove the limb with a topside cut started several inches above the underside cut.  Cut away the remaining stump by first making another safety cut - a shallow incision from below that is flush with the trunk.  Then saw from above until the cuts meet