We recommend pruning certain types of shrubs and trees before growth begins, including foliage shrubs like barberry and dogwood, as well as apple and pear trees for maintenance. For hydrangeas, pruning depends on the variety; arborescens (smooth) varieties can be pruned to the ground in spring, while macrophylla (bigleaf) hydrangeas are pruned after they bloom. You should also prune out winter-damaged branches and remove any water sprouts and suckers that grew vertically or from the base of the plant. Arborvitae, Juniper, Yew, and Hemlock can be pruned at any time through mid-summer, though it is best to maintain their natural form.

Avoid pruning spring-flowering shrubs and trees, such as azaleas, lilacs, and forsythia, as well as oak trees (from March to October, to prevent damage from oak wilt.) You should also avoid pruning birch and maple trees when sap is running in the spring, as this causes them to “bleed” sap. Instead of spring pruning, wait until after these plants have bloomed or after the period of high disease risk.

In summer, prune flowering shrubs like re-blooming roses, forsythia, mockorage, lilac and spirea right after they finish blooming; lightly prune fruit trees to improve fruit production; cut back or pinch perennials like monarda and salvia to encourage more blooms; remove dead or broken branches from any tree or shrub; and shape hedges and topiary. You can also thin out large deciduous trees and manage aggressive shoots and overreaching branches from trees and shrubs. Prune maple and birch in the summer to reduce sap bleeding.

Avoid pruning flowering plants, especially those that bloom on new wood like hydrangeas, to preserve their blooms for the season. Also avoid extensive pruning of fruit and shade trees, which can reduce their energy production and leave them vulnerable to disease, sunscald, and insect damage. The best time to remove dead, diseased, or damaged branches is anytime, but general pruning should be limited to avoid stressing the plants during the growing season.

Fall pruning should focus on removing dead, damaged, or diseased wood from trees and shrubs, as well as cutting back perennials to a few inches above the ground, especially if they suffered from disease.

Avoid removing live buds or pruning sensitive plants like lavender or marginally hardy perennials in the fall, as this can cause winter damage. For most other woody plants, wait until late winter or early spring for major pruning to allow the plants to remain sturdy and protect their buds. Do not prune off the flower and leaf buds that trees and shrubs set for spring growth. Shearing is also best reserved for spring or summer.

In winter, prune deciduous trees (like maple, oak, apple trees), roses, and dormant evergreens (like boxwood and holly). The primary goals are to remove dead, damaged or diseased branches, improve airflow and light penetration, and shape the plant by thinning out crossing or rubbing branches.

Avoid pruning spring-flowering plants such as magnolias, dogwoods, lilac and forsythia, as they have already set their flower buds. Wait until after these plants have finished flowering to prune them. Pines and other conifers should not be pruned in winter. They have a specific pruning time in early June or July.