Pruning Trees & Shrubs Guide | Fort Collins, CO
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  • Writer's pictureKassi K.

The Ultimate Guide to Pruning Trees & Shrubs

Updated: Oct 31, 2023

While you may not realize it, the health of your trees and shrubs very much depends on pruning. Pruning your trees, shrubs, and even your perennial plants properly encourages healthy growth, promotes an aesthetically pleasing shape, helps avoid pests and disease, and more. So, if you are unsure of how to prune your trees and shrubs or are looking for some guidance, we are here to help!


Pruning Trees & Shrubs

Why Prune Shrubs and Trees?

There are many reasons one could come up with for why you should prune trees and shrubs. Here are some of the most important reasons for pruning shrubs and trees.


Encourages New Growth

Pruning trees and shrubs actually stimulates new growth. This is one reason why it is not good to prune your trees and shrubs in the fall because this sends signals to the plant to begin growing during a season when it should really be storing energy and preparing for dormancy. Pruning also has a major influence on flowering shrubs and fruit trees, stimulating blooming and fruit production.


Create an Aesthetically Pleasing Shape

Pleasing Shape

Pruning is also very often done to influence the shape of a plant. All trees and shrubs can be pruned according to a desired shape, however, some can handle more extreme pruning/shaping than others, so be sure to know which type of tree or shrub you have and the extent to which it can handle being cut back.


Avoid Pests and Diseases

Pests and diseases are able to affect your trees and shrubs more easily in situations where there is a lack of circulation or dead branches that could harbor unwanted guests. Some branches naturally grow inward, and these branches should be pruned off to help encourage outward growth and to avoid the center of the tree becoming so dense with branches that airflow is restricted. If any branches on your trees or shrubs have died or broken off leaving a splintered break, this should also be pruned off to avoid pests or disease settling in and harming your tree further.


Eliminate Safety Risks

If there are any dead branches anywhere in your tree or shrub, not removing these can hinder the growth of new, healthy branches. These dead branches, depending on the size, could also pose a safety risk to any people below, could damage your home, or could cause damage to any other landscaping elements in the vicinity of your tree or shrub. Due to these reasons, dead branches should always be removed from a tree or shrub.


When To Prune Trees

Above we mentioned that fall is not the best time to prune trees since this stimulates growth when cold weather and dormancy are right around the corner. So, if you are wondering when to prune trees, it is best to prune them in the spring. Fruit trees are best pruned in early spring, and other trees such as maple trees, birch trees, or aspen trees are better pruned in late spring to early summer. In general, pruning trees is best done before new growth begins to emerge or before buds begin to set. If you prune after new growth has emerged or after buds have set, you are really just working against your tree by removing new growth that it has devoted energy to. The only reason for fall pruning is to remove any dead or diseased branches that could break due to snow or wind and cause more damage to the tree and its surrounding area.

Prune Trees

Pruning Schedule for Trees:

  • Oak Trees: Late Winter/Early Spring

  • Apple Trees: Late Winter/Early Spring

  • Pines & Spruce Trees: Late Winter/Early Spring

  • Honey Locust Trees: Late Winter/Early Spring

  • Maple Trees: Late Spring/Early Summer

  • Birch & Aspen Trees: Late Spring/Early Summer

  • Juniper & Arborvitae: Late Spring/Early Summer


When To Prune Shrubs

Shrubs are also best pruned at the beginning of the growing season. Shrubs such as roses or hydrangeas should be pruned back in early spring. It is more important for shrubs like these to be pruned before new growth emerges. (If you would like more information on how to prune roses, check out our blog on How to Grow and Care for Roses.) Not every shrub requires the same care, though. For example, lilac bushes set their blooms for the following year almost immediately after they bloom, so if you prune them early in the spring or in fall, you will likely prune off all the buds and miss out on your beautiful and fragrant flowers until the next season. For this reason, it is best to prune lilac bushes in late spring or early summer as soon as it has finished blooming. This goes to show that it is important to do your research before pruning different types of trees and shrubs. If you are unsure of the pruning needs of any plants in your landscaping, feel free to let us know so we can help!


Pruning Schedule for Shrubs and Perennials:

  • Juniper & Arborvitae: Late Spring/Early Summer

  • Roses: Early Spring

  • Hydrangea: Early Spring

  • Lilac Buses: Early Summer

  • Ornamental Grasses: Late Winter/Early Spring


How To Prune Trees

Depending on the tree you are pruning, this answer may vary slightly. However, in general, it is best to remember to have a reason for pruning a branch. Removing a branch that appears damaged, removing crossing or rubbing branches, removing branches to increase the height clearance of the tree, removing branches to thin out the interior of the tree, or removing branches to improve the structure of the tree are all good reasons, and there are plenty more. It is just best to avoid chopping off branches for no reason.


When you do prune trees, it is best to make your cuts just outside of the branch collar, or the point where one branch attaches to another larger branch or to the trunk of the tree. This branch collar is usually able to be identified by a raised or wrinkled looking ring of bark around the base of the branch. Pruning too close or too far away from this point can affect the way the tree heals.


Prune Trees

Something else that is very important to be aware of when pruning trees is to not remove more than 1/3 of the living portions of the tree. Removing more than this can cause the tree to go into shock or can even cause the tree to die. This can be hard to judge sometimes, but it is best to play it safe if you are ever unsure about the amount of living tissue you are trimming off your tree.


If you are considering pruning a newly planted tree, it is best to wait to do any pruning until the tree is established. For some newly planted trees, this can take 1-2 years. Pruning a tree that has not yet established itself can cause the tree to begin to divert its energy towards limb and foliage growth before its root system is strong enough to support the new growth. It is always best to limit the pruning of adolescent trees to the removal of dead or damaged branches, crossing limbs, or limbs interfering with the main stem.


Suckers or waterspouts are usually a waste of energy. They are not aesthetically pleasing, do not contribute to a strong and healthy structure, and divert energy away from other more important parts of the tree. Suckers can usually be identified as new tree-like growths emerging from the base of the tree, and water spouts are thin, twiggy bunches of growth emerging from growth nodes usually on the trunk of a tree. Such growths should be removed right away and are easiest to remove when they are young and green.


When pruning trees, always be sure to use sharp, clean pruning tools. Not only does this make the job much easier, but it also is important for the health of your tree. Making a rough, jagged, or splintered cut makes it difficult for the cut to heal properly. This opens the door to pests and diseases. This is also why it is important to trim back broken branches, as the splintered crevices of the break are the perfect home for unwanted pests.


Pruning Steps:

  1. First, start by removing dead, dying, broken, or diseased branches and stems.

  2. Next, remove water spouts and suckers

  3. Then inspect your tree for any crossing or inward growing branches and remove these.

  4. Lastly, prune for structure and visual appeal, keeping in mind not to remove more than 1/3 of the living parts of the tree. When in doubt, leave it for next season.


How To Prune Shrubs

Prune Shrubs

Shrubs require very similar pruning. Remember to allow any newly planted shrub to establish itself before doing any pruning for shape. The only pruning that should be done on newly planted shrubs is to prune off dead or damaged limbs. Even after your shrub is established, be sure to never remove more than 1/3 of the living tissue of the plant, as this could cause it to go into shock. Think of it like this: removing more than 1/3 of a plant means you are abruptly taking away more than 1/3 of its energy reserves, which can easily shock or kill the plant. With shrubs, it is especially important to make sure the base of the shrub has good air circulation since many of the branches come straight from the base of the plant. Make sure that mulch isn't piled up around the base and prune off any suckers or inward-growing shutes. This will help to ensure good airflow around the base of the plant and will help to discourage pests and disease. As we mentioned above, always be sure to use clean, sharp tools for your own sake as well as the sake of the shrub. Using dull tools will create more work for you and can cause additional damage to the shrub, making it vulnerable to pests and disease.


Pruning Steps:

  1. First, remove any dead, dying, broken, or diseased parts of the shrub.

  2. Next, remove any suckers that may be shooting up at the base of the shrub.

  3. Then inspect your shrub for any crossing or inward growing branches and remove these.

  4. Lastly, prune for structure and visual appeal. Remember not to remove more than 1/3 of the living parts of the shrub. When in doubt, leave it for next season.

How to Prune Trees and Shrubs

If you have any questions about how to prune shrubs or trees, please let us know. Our main recommendation for you is to do your research and familiarize yourself with the different types of trees and shrubs that are planted in your landscaping. If you are unable to identify a certain tree, shrub, or perennial plant, check out our Plant Finder or contact us and we can help you identify your plant and can help you learn how to best care for the specific plants in your yard. We hope you found this information useful, and we look forward to helping you help your landscape stay healthy and beautiful!

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