On average, pruning every 2 to 5 years is best. While young trees need to be maintained more often (generally, every 2 to 3 years), more mature trees operate on a 3 to 5 years cycle. A Certified Arborist can best figure out the period that works best for your particular tree.
The General Pruning Timeline for Healthy Trees
But in general, most arborists will suggest the following: Mature Trees—Should be pruned or trimmed every 3-5 years. Juvenile Trees—Should be pruned or trimmed every 2-3 years.
Overgrown trees can pose a serious risk to your property and your family. Dead or damaged branches can fall and cause damage to your home or car or even injure someone. In addition, overgrown trees can block sunlight and views and can even damage foundations or driveways.
Cut too much and you'll risk nutritional deficiencies or branches that are too weak to tolerate the wind or fend off diseases or insect invasions. Over pruning and topping can permanently disfigure your trees, or even kill them. Further, a tree's foliage is important for protecting it against excessive sun exposure.
Generally, the best time to prune or trim trees and shrubs is during the winter months. From November through March, most trees are dormant which makes it the ideal time for the following reasons: Trees are less susceptible to insects or disease.
As a general rule, prune spring-blooming trees immediately after they flower. Prune trees that bloom in the summer or fall in late winter or early spring before the end of their dormancy. Routine pruning of dead or dying branches can be done at any time.
Surely there's one chore you can tick off your endless outdoor to-do list—and maybe even get a jump on for spring. The rule on fall pruning is, generally speaking, don't prune in fall. But there are a few trimming tasks you can take on with confidence, provided you approach the job with self-control and a plan.
An improper cut like a flush cut (cutting too close to the trunk) or a stub cut (cutting too far from the trunk) can cause irreversible damage to a tree. A flush cut removes the branch collar and leaves a large wound in the side of the tree that won't heal properly.
Over pruning reduces the foliage needed to make food for the tree, so in effect, it starves it. When a tree has been over pruned, you may not see much new growth during the spring. In the winter, more branches than usual will break as a result of heavy loads.
In fact, it's healthy to do this every now and then. Plants will benefit from a good trimming the most during spring and summer, which are their active growing seasons. Trimming can be done to both vines and trees to encourage new, fuller growth along the plants, as well as to get rid of any yellowing or dead sections.
Late summer or early fall pruning causes vigorous re-growth of tissue, which in some cases may not harden off by the time winter arrives, leading to possible cold damage to the new growth.
Choose the Right Time
Likewise, prune in the early morning or late afternoon to avoid the newly cut ends of branches becoming scorched by the hot sun. Wait 48 hours after rain to prune, to allow plants to dry out and avoid fungal diseases. When pruning, make cuts just above leaf nodes, or buds.
Restore shape and structure
Summer is an excellent time for restorative pruning. You can correct problems that have resulted from over-pruning or poor pruning. You can also clean up damage from winter and spring storms. Proper pruning will begin to restore most plants' natural shape.
Proper branch pruning
Cut on a small branch or twig about 1/4 inch above the bud. To shorten a branch or twig, cut it back to a side branch or make the cut about 1/4 inch above the bud. Always prune above a bud facing the outside of a plant to force the new branch to grow in that direction.
In an exposed garden, where a lot of wind blows, it's a good idea to shorten each stem by about one-third. This basic maintenance pruning should have you cutting back each stem to a bud that is between six and 10 inches above ground level.
The 1/3 rule involves cutting about 1/3 of wood during any pruning activity. This moderate pruning practice is a balanced approach to thinning out shrubs to stimulate new growth. The plant loses a good amount of stems, usually on the top section, allowing more light and air to enter the inside of the plant.
ALWAYS prune back to or just above a growing point (branch or bud) or to the soil line. NEVER leave a stem or branch stub. NEVER top a tree to “rejuvenate” growth.
Watering is very important during the couple of weeks or more that a plant is recovering from root pruning. Right after pruning, I give the whole pot a thorough soaking. As new growth begins, I make sure to thoroughly wet all the soil at each watering.
In pruning, there are three primary types of pruning cuts, thinning cuts, reduction cuts, and heading cuts, each giving different results in growth and appearance.
Municipalities and homeowners often remove the lower limbs for pedestrian and vehicular clearance or to let the sun shine in for grass to grow. Mature trees, especially evergreens, benefit when healthy lower branches are left intact. Removing large limbs can increase the risk of decay.
How to Fix an Over-Pruned Tree or Shrub. While some plants need a heftier prune than others, in general, the golden rule is to trim no more than 15 to 20 percent of a tree's canopy at one time. Keep that in mind for next time.
By not cutting back the statuesque achilleas, eryngiums, perennial astilbes, sedums, alliums and many ornamental grasses, you can enjoy their structure against a winter sky. The sight of their stems silvered with frost adds a whole new level of interest to the garden.
In fact, it is better to prune a little at a time than to make drastic cuts. For plants that shed their leaves (deciduous plants), the best time for winter pruning is from the beginning of November to the end of February. To prune evergreens you can start later, from mid-December, and continue until February.
The best time to prune is after flowering. If the plant needs to be renovated, or severely reduced, this can be done late winter and early spring just before growth begins.