spring buds
Now is the time to prune many trees and shrubs but some plants prefer summer pruning so be sure to do your research before cutting.

The basic goal of pruning is to increase the health and productivity of the plant, to shape it to a pleasing form or to control growth and size.

A note on aesthetics – try to follow a natural line, we have all seen bad haircuts on plants so when in doubt leave it to its natural growth habit, chances are it will work itself into a lovely form all on it’s own. If you do decide to prune be sure to step back between cuts and re-access the look before continuing. And remember friends don’t let friends hack their landscape.

Basic tips
Before you begin:
– Make sure it is the right time of year to prune this particular plant
– Prune on a dry day to minimize damage
– Be sure to use sterilized pruners to keep from spreading disease

Technique:
– Make clean cuts with sharp tools as jagged edges can damage the plant.
– Cut at a 45 degree angle and don’t leave a flat surface that can collect water.
– Cut smaller branches1/4 inch above the point where branches connect or directly above a bud point, not in the middle of the branch. Angle cuts with the pointy end closest to the last bud point to encourage growth in that direction.
– Cut larger branches parallel to the remaining branch or trunk and be sure to leave the branch collar (the bulge at the base of the branch) intact as it is key to the healing of the cut.

As you begin
– Stand back and envision the shape you want to achieve.
– First take off dead or diseased branches.
– Remove overgrown and small weak branches to increase light and air flow.
– Trim branches that cross and rub against each other.
– Don’t remove more that 1/3 of the plant (exceptions are roses and grasses).

When to prune

Winter or early Spring pruning:
Typically, summer and fall flowering plants bloom on new growth so they need to be pruned early in order to encourage the growth that will then produce more blooms.
We have had weird wether this year so an overall timing is difficult to gauge –  a rule of thumb is that you want to prune before buds swell on the plants.
Many roses
Sambucus – elderberry
Corylus – Filbert
Kiwi
Wisteria
Crabapple
Bittersweet
Ornamental grasses
Fruit trees especially apples and pears are generally pruned in the winter but some people prefer to prune the stone crops – cherries, apricots, plums and peaches later in the season.

Later season pruning:
Spring flowering plants are pruned directly after they finish blooming. The goal is to encourage new growth now because these plants need the spring growth to develop into old wood over the season in order to bloom again next year.
Camellia
Ceanothus
Cistus
Witch hazel
Honeysuckle
Pussy Willow
Forsythia
Jasmine
Some roses
Passionflower

If in doubt you can attend a pruning workshop with friends of trees:
http://friendsoftrees.org/blog/2012/01/25/winter-pruning-workshops-with-portland-fruit-tree-project/

Special notes on pruning roses:
Prune all shrub-style roses; hybrids teas, floribundas, and grandifloras. Cut back to aprox 20 inches tall, cut out any dead wood and thin weak growth, trim out limbs that cross one another and cause rubbing, prune remaining branches just above an eye (dormant leaf axel) facing away from the middle of the bush.

Climbing and rambling varieties should be shaped to fit the existing spot, start by cutting out dead wood and thin weak growth or limbs that cross one another and cause rubbing. Then envision the line you want the rose to take and trim accordingly to encourage growth. Remember that any cut you make will encourage a branch to from from the next lowest eye and so growth will move in that direction.

Have fun and wear gloves and protective clothing!