University of Cooperative California Extension Figure 1. Heading-back is cutting to a tub, small lateral , or bud. before after A A S E R I E S B A A A A A A Thinning-out removes a branch (A) Figure 2. or cuts to a large one (B). B PRUNING C A TREES AND SHRUBS The University of California prohibits discrimination against or harassment of any person on the basis of race, color, national origin, religion, sex, physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or status as a covered veteran (special disabled veteran, Vietnam-era veteran or any other Figure 3. Removing a large limb; first cut at (A), second (B). veteran who served on active duty during a war or in a campaign or expedition for which a campaign Final cut made at crotch (C) badge has been authorized). University Policy is intended to be consistent with the provisions of applicable State and Federal laws. TRUNK Inquiries regarding the University’s nondiscrimination policies may be directed to the Affirmative DO NOT CUT Action/Staff Personnel Services Director, University of California, Agriculture and Natural Resources, BEHIND THE BRANCH BARK RIDGE. CUTS 1111 Franklin, 6th Floor, Oakland, CA 94607-5200 (510) 987-0096 BEHIND THE BBR BRANCH WOUND THE TRUNK BRANCH BARK RIDGE. DO CUT BRANCH COLLAR FROM DO NOT OUTSIDE OF INJURE OR REMOVE THE THE BRANCH BRANCH COLLAR. BARK RIDGE. THE TREE’S CHEMICAL PROTECTIVE ZONE FORMS IN THE BRANCH COLLAR Figure 4. Make third cut outside small ridge of bark, angling it away from trunk slightly Thinning out means through the branch, one to number and spacing of main Pines and other conifers— they are dormant and evergreen PRUNING removing a branch to its origin three inches farther out than branches is obtained. Pruning Because of their natural ten- trees before growth resumes in TREES AND SHRUBS or to another branch that can the first one. Remove the to direct growth and establish dency to produce a strong, the spring. Prune spring- replace it (Fig. 2). Resulting remaining, foot-long stub with main branches is best done dominant, central leader, pines flowering trees and shrubs as If the right plant is selected new growth is usually spread the third cut, also a downward when the tree is actively grow- and other conifers usually soon as flowers fade and before for the right spot and purpose fairly evenly throughout the one. Avoid making cuts flush ing. require less pruning than new growth begins in late in the home yard or landscape, plant, so there is little change in against the trunk when Mature trees—Prune out broad-leaved trees to train and spring. Prune summer- and there is usually little need for its natural appearance and removing branches. Instead, dead, weak, diseased, and direct growth; however, the fall-flowering trees and shrubs make the cut just outside the pruning mature trees and overall shape. Leaves will grow insect-infested branches. same principles apply to in late winter or spring before small ridge of bark formed on shrubs. Indeed, unnecessary more in the center of the tree or Remove low, broken, and maintain tree health and new growth begins. Avoid the upper side of the crotch or improper pruning can ruin shrub since more light can crossing branches. Also, structural soundness and, if pruning tender subtropicals and between the branch and the penetrate into the interior. remove branches that could fall necessary, to control size. deciduous trees and shrubs late or seriously damage plants. trunk, angling it slightly away or otherwise cause injury or Prune junipers and similar in the growing season since Proper and timely pruning, from the trunk (Fig. 4). MAKING THE CUT property damage. Thin out the though, can be useful to train Covering cuts with tree seal shrubs with a strongly such pruning might stimulate young plants, improve Use properly sharpened, or pruning paint is not interior only if needed to let spreading growth habit by new, tender growth that is appearance, control shape and clean pruning shears or loppers recommended. Simply letting more light in or to enhance a thinning out leggy, overly susceptible to winter cold size, influence flowering and for small branches and saws for the cut air dry is best. view. Although pruning to con- vigorous branches, especially injury. fruiting, encourage new large ones. When pruning trol size is not recommended, it those overgrowing and shading Ask your nursery or garden growth, and remove damaged diseased plants, clean pruning PRUNING STRATEGIES might be necessary in some out lower ones and challenging center professional for cases; if so, thinning out is pre- the shrub’s natural pyramidal additional information and or pest-infested branches. tools in household bleach after Young trees—Prune only ferred rather than heading back. shape. Prune naturally assistance about pruning trees each cut. Remove unwanted enough to direct growth and TWO TYPES OF PRUNING CUTS Drastic heading back of a rounded shrubs like arborvitae and shrubs. small branches, including those correct any branch structural mature tree, popularly called by thinning out individual The two main types of from below the graft union or weaknesses. At the height suckers and watersprouts, “topping”, “coat racking”, or branches, removing about 1/ - pruning cuts are heading back desired for the intended use of 4 close to the trunk or branch “hat racking”, is a severely 1/ the previous year’s growth. and thinning out, and trees and the tree, select five to seven 2 from which they arise. Make damaging, unprofessional, and shrubs respond differently to main branches spaced one to small cuts most easily by a even dangerous practice, and is each type. Heading back two feet apart vertically with TIME OF YEAR TO PRUNE single, upward cut. When to be avoided. means cutting a branch back to wide angles of attachment. heading back small branches, Shrubs—Prune shrubs to Remove damaged, weak, a stub, smaller branch, or bud 1 Head back or thin out branches make the cut about /4 inch keep their natural shape, thin- (Fig. 1). It usually results in a interfering with the selected diseased, or insect-infested from a bud or branch pointing ning out older, taller growth. To flush of vigorous, upright, main ones. If main branches growth or small, unwanted in the direction of the desired control size remove old growth branches anytime. Pruning just The author is Donald R. Hodel, dense shoots from just below new growth, usually one point- are slow to develop, head back at or near the ground and leave before the period of most rapid Environmental Horticulturist, the cut. These new shoots are ing out and away from the the central leader (trunk) at the the younger, shorter stems. growth, usually in the spring, University of California Cooperative often weakly attached and split plant. height at which the first branch Thin out and/or head back new promotes rapid growth. Extension, Los Angeles. out easily. Heading back Remove large branches in is desired. Select the most growth as needed to reshape usually changes the shape of a two steps involving three cuts vigorous new shoot that Conversely, pruning when the plant. tree or shrub dramatically. (Fig. 3). Make the first cut develops from the cut as the growth is nearly complete for Hedges—Prune back to the Generally, heading back is most about one-third through the new leader and one other as the season tends to retard point of the last cut, keeping appropriate when training and underside of the branch a foot the first main branch. Repeat growth. Direct and train the the top slightly narrower than directing growth of young trees out from where it is to be this process as the leader growth of young trees during the bottom to ensure adequate or when creating hedges with removed. Make the second cut, develops until the desired the growing season. Generally, shrubs. a downward one completely light reaches lower leaves. prune deciduous trees when.