When to Prune Your Trees and Plants

Fall yard clean-up is on all our minds! There’s something satisfying about seeing your yard ready for the winter months. From raking up leaves and removing annuals, to mulching your perennial garden beds.

It is during this fall yard maintenance routine that the Rock Solid experts are often asked about which plants to prune, which trees should be pruned, and which should be left alone for the winter.

If you have any questions about your yard and how our team can simplify your fall yard cleanup and maintenance, contact us about our fall service packages.

Pruning Encourages Healthy Plants

Have you ever seen someone prune back a tree extensively and wonder if it was too much? This pruning is extremely beneficial for many trees and shrubs.

First, it promotes flower and fruit development. You will often notice a marked improvement in your fruit yield after a proper pruning.

Second, pruning provides an opportunity to reshape or control the size of your plant. You can remove any dead, diseased, or unwanted branches. Plus, many trees or shrubs (e.g., lilacs) will produce unwanted shoots or suckers near the ground that should be removed. You can also keep your evergreens well-proportioned and create denser, more filled-out hedges.

Plant Pruning Schedule

Trees

Generally, the ideal time to prune your trees and shrubs is late winter, which is February to April for Minnesotans. By cutting back your trees at this time, you’re providing time for your trees to heal quickly before the new growth starts and limiting potential exposure to disease. If you cut during earlier winter, it takes longer for the tree to heal.

Crab Trees and Other Fruit Trees

Flowering crab trees, other fruit trees, and most deciduous trees require new growth in order to produce buds and flowers. Removing older or dead branches helps stimulate new growth for a greater number of blooms.

You can prune these trees in mid or early winter, but it does make the tree more vulnerable to cold-related injuries. Make sure the tree have become dormant by waiting until after the first killing frost. This prevents new growth happening in the late fall.

Oak Trees

The one exception to take note of is oak trees. Oak trees should only be pruned well into October to prevent oak wilt. Minnesotans are in a constant battle with a beetle that loves freshly cut oak. These beetles carry a fungal disease that wreak havoc on your oaks. By trimming in October, it is too cold for the beetles to thrive.

As suggested by the University of Minnesota, if your oak trees do suffer damage during the year, apply a wound dressing or latex paint to inhibit beetles from being attracted to your trees.

Shrubs

Similar to flowering trees, shrubs like sumacs, honeysuckles, dogwoods, smokebush, and burning bush are best pruned in late winter before the blooming season. It enables beautiful growth and plentiful blooms during the season. To prune your shrubs, using sharp shears, cut away from the direction of growth at 45° to promote fast healing.

Lilacs, Azaleas, and Magnolias

Shrubs that bloom on old wood have a different pruning schedule. Lilacs, azaleas, and magnolias should be pruned in spring or early summer after flowering. This prevents you from removing new buds that make these shrubs an attractive addition to your yard.

In early summer, removed all the spent blossoms and prune back any dead branches. Lilacs benefit from a solid pruning but try to keep at least a third of the shrub for survival. If you didn’t prune your lilacs this summer, wait till the next summer, as you run the risk of removing any new growth and buds that develop over the later summer and fall.

Evergreen Shrubs and Hedges

Evergreen shrubs fall into two categories: needle-bearing or broadleaf.

Needle-bearing evergreens such as pyramidal cedars, junipers, and yew are pruned in early spring. Make sure to remove any yellowing tips that were killed through the winter. You will likely have to prune your evergreens again in late spring after their rapid growth to maintain your desired shape.

Broadleaf evergreen shrubs like rhododendrons, holly, and boxwood are a bit trickier. For flowering shrubs, waiting until they are done flowering is preferred. For other shrubs like holly that you’re planning on using in your winter decorations, you may choose to prune in the winter. Whereas other broadleaf plants that are used for hedges such as boxwood can be treated similar to the needle-bearing evergreens.

Perennials

Pruning perennials is part of your fall clean-up routine. However, there are many exceptions. The best course of action is to research your specific plant to make sure you’re pruning at the right time.

For those plants that you’re trimming in the fall, make sure they’ve experienced a hard freeze so that your plants are dormant. Otherwise, they may produce new growth that is instantly killed by our Minnesota winter. Trimming and removing any dead plant debris also helps prevent plant diseases, such as powdery mildew, and insect pest.

Some perennials to cut back in the fall include bellflowers, daylilies, salvia, black-eyed Susan’s, and hydrangeas that bloom on new wood. Hydrangeas that bloom on old wood should be pruned in the late winter.

However, you may wish to leave some plants such as yarrow and ornamental grasses to add interest to your winter landscape. Also, plants and shrubs with dried berries help feed birds and other wildlife through the cold months. Other plants that have tender roots, such as mums, shouldn’t be trimmed down as their foliage protects them during the winter.