Pruning - When To for the NH Area

 * Always avoid pruning during the extreme heat of summer while plants are stressed.

SPRUCE, PINE, FIR - Not needed - but for maximum fullness, trim tips after the new growth in late spring has hardened off. Mid June is a good time for this.
EVERGREENS - Arborvitae, Boxwood, Cypress, Euonymus, Hemlock, Holly, Yews, Junipers, can be pruned most anytime. Usually once a year or less is sufficient, but more trimming may suit your taste. (Prune Holly at Christmas time and use branches for decorating)
FRUIT TREES - Fruit trees should be trimmed in late winter or early spring. The leaves are off the trees at these times and you can see better what your doing. Thinning the tree enables the fruit to get more sun, thus helping the fruit ripen. Also base sucker should be kept trimmed. Dormant oil spray should be used before the leaves come out, and fruit tree sprays can be used after the blossoms have dropped. See Fruit Tree page for additional information.
RHODODENDRONS AZALEAS AND ANDROMEDA - These plants should be trimmed right after blooming. In NH mid June is about right. These plants set bud in the summer. Trimming them too late will result in less - or no flowers for the following spring.
MOUNTAIN LAUREL - Mt. Laurel is best trimmed also right after blooming time. This should be done sometime in early July.
DECIDUOUS SHRUBS - Barberry, Privet Hedge, Burning Bush, can be pruned at anytime.
Dogwood (shrub type) Potentilla, Spirea, and Rose of Sharon should be done in fall after flowering or very early spring.
Lilac, Forsythia, Weigela, and Viburnum require pruning right after blooming stops, the time will vary with each variety.
Wisteria, prune in late fall (this may also increase flowering in the spring).
Hydrangea, depends on the type - most you would prune in early spring when new leaves appear on last year’s wood. Do not cut hydrangeas down to the ground. *If you are unsure of your hydrangea type and have had problems with it not flowering do not prune every branch- prune 1/3 of the branches leaving some unpruned. Some Hydrangea only flower on prevoius years growth if protected from winter injury. See Fall Winter Prep for more information.
FLOWERING TREES - Flowering trees are generally trimmed after they have flowered, this includes Dogwoods, Lilacs and Magnolias, Ornamental Pear & Plum.
Crabapples can be trimmed most anytime, although after flowering is still best.

SHADE TREES - Shade trees can be pruned most anytime except extreme heat of summer. When the leaves are off the trees it's a bit easier to see what your doing.

A FEW MORE WORDS ON PRUNING. Natural pruning is trimming by using the natural outline of the plant. Trim just the long, out of shape branches. This will give a more natural look and be less formal looking. Also remember to keep tree limbs carefully trimmed away from utility lines. In our NH area the power company patrols and prunes trees beneath lines without regard to how they will look when they are done.