Perhaps no other aspect concerning trees, shrubs, and vines confuses amateur gardeners as much as pruning. When to prune? What to prune? How to do it? These are just a few of the questions asked.

Pruning is a practice that is periodically required on all woody landscape plants. Mature or young trees require different approaches.

Mature Tree

PRUNINGOn mature trees, pruning is required to remove dead and dying branches to maintain plant health and safety. This pruning type is referred to as cleaning. Research has now documented that thinning, the removal of live branches to reduce density, significantly reduces wind resistance and subsequent storm damage. Thinning should only be done on trees where the crown is "too dense". A David's Tree Service arborist has training and experience to evaluate this attribute. Thinning should be concentrated on the outer portions of the canopy, leaving as many branches on the interior crown as possible. In some instances, the crown or individual branches require reduction in length to improve the form and shape of the plant, to eliminate interference with objects and structures, and to compensate for structural weaknesses. Lower branches may require pruning for similar reasons. This process, known as raising, also can be used to increase the amount of light for turf grass and ground covers beneath the crown of a tree. David's Tree Service arborists are trained to evaluate the condition of your trees and determine the type(s) of pruning required to balance your goals and those of managing plant health and safety.

Young Tree Pruning

pruningOne aspect of pruning that is most frequently overlooked by consumers is structural pruning of young trees. Trees evolved in forests where they tend to grow straight and lose lower branches due to competition for light. When planted in full sun in the landscape, many species tend to develop multiple stems/leaders that are more prone to failure. Lower branches tend to grow at the same rate as the terminal leader that results in weak attachments that also are likely to fail later in the life of the plant. So, pruning trees when they are young and growing quickly is critical to ensuring a strong framework for future growth. This pruning focuses on maintaining a single dominant stem unless multiple stem "clumps" are specifically desired. Branches are pruned so their size remains proportional to the stem diameter at their point of attachment. As trees grow, some branches are removed to ensure adequate spacing between permanent scaffold limbs. The shape of the tree is maintained to provide a natural open grown form typical of the species.


Specialty Pruning

David's Tree Service arborists can also develop and maintain formal pruning styles including pollarding, espalier, pleaching, and topiary. Fruit tree pruning is becoming increasingly popular as more consumers grow apples, pears, citrus, and other fruit bearing plants in their gardens. Vista pruning, which is judicious removal of branches to enhance a specific view from a defined location, is also frequently performed especially for consumers with homes near mountains or the shore.

When To Prune


When to prune depends on several factors, notably the species being grown and the reason you are pruning. Pruning can actually stimulate growth. Pruning back a weak branch in late winter or early spring will often cause the new growth that replaces it to grow much faster. To slow growth down, prune in early summer. These are the two basic principles of pruning, but there are numerous exceptions.

Trees and shrubs that bloom in spring (blooming on branches formed the previous year) are usually pruned immediately after they finish blooming. This stimulates greater flowering the next year. Those that bloom on new wood (usually summer-bloomers) can be left until the following spring. Most formal hedges can be pruned at any season, as needed. It is preferable not to prune at the very end of summer since this can produce new growth that will be susceptible to winter damage. Informal hedges are pruned after blooming.

There are two kinds of coniferous plants that require different types of pruning. The first are those that put out their entire year's new growth all at once, in late spring. This group includes pines, spruces, and firs. They can be pruned by removing up to two-thirds of the new growth while it is still fresh and pale green. Do not prune them back to old wood because they will not produce new shoots from those sections. Conifers that grow throughout the summer, such as yews, arborvitae, and junipers, are pruned once in early summer and again, if necessary, later in the season. They can also be pruned more heavily, down to old wood if necessary.

What To Prune

What to prune depends a great deal on the effect you want to create. There are major differences between the way to prune shrubs and the way to prune trees.

Except under rare circumstances, ornamental trees should be left to take their natural shape and appearance, resulting in little need for pruning. They are usually pruned only to remove damaged or diseased branches or ones that cross, rub together, or form an overly acute angle with the trunk.


Topping is not recommended.

Sometimes the upper limbs of overly dense shade trees can also be thinned to open them up, allowing more light to reach the garden below. Two other circumstances requiring pruning are when two leaders form (remove one) and when suckers (also called water sprouts) appear. Suckers are upright, unbranched sprouts that appear at the base of the tree or on the lower trunk.

Young trees should be pruned as little as possible at planting time because hormones released by leaf buds and newly emerging shoots stimulate the growth of new roots. Weak and damaged branches, however, can be removed. Once young trees are established, they can be pruned to remove weak growth and give them a better form. When the tree has attained a fair height, any lower branches that interfere with human movement can be removed, preferably over a two- to three-year period.

One common pruning technique in tree pruning is topping, or heading. This is not recommended. Topping involves pruning back the large branches of deciduous trees in an indiscriminate fashion to change the tree's natural shape into that of a round ball. This causes all sorts of problems, including wounds that heal poorly, severe dieback, and increased danger of wind damage. It also destroys the tree's natural symmetry. The process must be repeated, since topped trees will grow back even more vigorously.

Different pruning techniques are used on shrubs, depending on the desired effect. Formal hedges, topiaries, and other closely clipped forms are sheared, which means all branches are clipped to the same length. Some shrubs that bloom on new wood are also sheared back annually to the base to encourage a maximum number of branches and thus more flowers. Subshrubs, which die back nearly to the ground anyway, should also be sheared back annually.