Pruning can help keep trees healthy, improve their structure and remove branches that are dead, damaged or creating problems.

But good pruning starts with knowing when to make the cut.

In southeast Wisconsin, the right timing depends on the tree, why you’re pruning it and the time of year. Most deciduous trees are best pruned once they’re dormant, while some flowering and fruiting trees have more specific timing needs.

Here’s what to know before you reach for the pruners.

Why Prune a Tree?

Trees don’t need to be pruned simply because a new season has arrived.

Pruning should have a purpose. That might include:

• Removing dead, broken or diseased branches.
• Correcting branches that cross or rub.
• Improving the structure of a young tree.
• Removing weak or competing branches.
• Addressing branches growing toward a building, walkway or other obstacle.
• Improving the tree’s form when appropriate.

Before removing a healthy branch, know what you’re trying to accomplish. Different trees have different growth habits and pruning needs, and removing too much can create more problems than it solves.

Fall Tree Pruning in Southeast Wisconsin: Don’t Rush It

Fall can be a great time to look closely at your trees and make a pruning plan—but early fall is generally not the time for major pruning.

Significant pruning can stimulate new growth. In September and early fall, that new growth may not have enough time to harden off before southeast Wisconsin’s cold weather arrives.

For most deciduous trees, wait until the tree is dormant in late fall or winter for routine or structural pruning. Once the leaves are gone, you’ll also have a much better view of the tree’s branch structure.

UW–Madison Extension recommends dormant-season pruning for most deciduous trees and notes that major pruning later in the growing season can encourage growth that may not be ready for winter.

Learn more about pruning timing from UW–Madison Extension.

What Can You Do in Early Fall?

September is a good time to inspect your trees.

Look for:

• Dead branches.
• Broken or storm-damaged limbs.
• Branches that cross or rub.
• Cracks or other structural concerns.
• Changes in leaves or bark that may indicate a problem.

Dead, broken or hazardous branches don’t need to stay on a tree simply because it isn’t dormant yet. Address those when necessary.

Healthy branches that you’re considering removing for shaping or structural reasons can usually wait for the proper pruning window.

A Special Note About Oak Trees

Be particularly careful with oaks.

Oak wilt is a serious disease in Wisconsin, and the fungus can be spread to fresh pruning wounds by beetles during the growing season. UW–Madison Extension recommends pruning oaks during dormancy when those beetles are not active.

If an oak is damaged during the growing season and must be pruned, different precautions apply.

Read UW–Madison Extension’s guidance on oak wilt.

Planning other September yard work? See our What to Do in Your Southeast Wisconsin Yard & Garden in September guide for watering, planting, flowers, perennials and other seasonal priorities.

Spring Tree Pruning in Southeast Wisconsin

Late winter and very early spring can also be a good pruning window for many deciduous trees—while the tree is still dormant.

Without leaves, it’s easier to see the tree’s overall structure and identify dead, damaged, crossing or poorly positioned branches.

Timing matters, though. Once buds begin swelling and trees resume active growth, the dormant pruning window is closing.

And not every tree follows exactly the same schedule.

Spring-flowering trees and shrubs may already have flower buds in place, so pruning before bloom can remove flowers you would otherwise enjoy. Oaks also require special timing because of oak wilt concerns.

The best rule isn’t simply “prune in spring.”

It’s identify the tree first, understand why you’re pruning it, and choose the right time for that particular tree.

UW–Madison Extension’s dormant tree pruning guidelines provide more information about timing and technique.

Gear Up with The Right Tools

When you’re ready to prune, use a tool suited to the size of the branch.

Hand pruners work well for small branches and lighter pruning.

Loppers provide more leverage for branches that are too large for hand pruners.

A pruning saw is appropriate for larger branches that cannot be cut cleanly with pruners or loppers.

Keep tools sharp and clean. A sharp blade makes a cleaner cut, and cleaning tools is especially important when you’ve been working with diseased plant material.

Make the Cut in the Right Place

When removing a branch, don’t cut it flush against the trunk and don’t leave a long stub.

Look for the slightly swollen area where the branch joins the trunk. This is the branch collar.

Make your final cut just outside that collar and leave the collar intact. This creates a smaller wound and allows the tree to respond naturally to the cut.

For larger branches, use the three-cut method to prevent the weight of the branch from tearing bark down the trunk.

See UW–Madison Extension’s pruning guidance for deciduous trees.

Not Every Pruning Job Is a DIY Job

Small branches that can be reached safely from the ground are one thing.

Large limbs, high branches, storm-damaged trees and branches near power lines are another.

If the job requires climbing, a ladder with a saw, work near utility lines or removal of a major limb, contact a qualified tree-care professional.

Have a Tree Question?

We can help! Ask our team for tips and tricks for pruning your trees this spring. Learn more about deciduous trees, evergreen trees, and ornamental trees for your yard.

About Thomas Greenhouse & Gardens

We grow our plants and flowers in our greenhouse. Our garden experts tend to them from seed to bloom with love and care. That means that our plants are strong, healthy and ready to be planted in your garden. Thomas Greenhouse & Gardens is the best choice for plants, annual flowers, perennial flowers, shrubs and trees near Mukwonago, Burlington, Lake Geneva and Waukesha.