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Help Your Trees Transition Into Autumn, Purdue Landscape Report

Posted on October 7th, 2025 in Forests and Street Trees, Urban Forestry, Woodlands | No Comments »

Purdue Landscape Report: It’s finally October, and we should be enjoying lovely fall temps and colors. While some of the trees are changing, it’s not necessarily due to the change in seasons. As I write this, the temperature is 84 F (29 C). I look out my window and see mostly green leaves with some colors from the short cold snap we had and some from heat and drought stress. Whether you are worried about the trees in your yard and community or not, there are some simple tasks that we can do to assist them as we await the cooler temperatures of Autumn.

A 3 foot radius mulch ring around a medium sized tree (Purdue Landscape Report)

Mulching: One simple task to better prepare your trees for winter is to add a new layer of mulch, which benefits your trees in multiple ways. Adding a 2-3 inch thick layer of mulch will better maintain moisture levels and buffer extreme temperature changes in the soil and will add some organic matter too. Mulching to the drip line will benefit the tree the most, but in the case of larger trees it’s not always feasible. Try for at least a 3-foot radius from the trunk and make sure to leave a 2 inch or so gap between the trunk and the mulch. Remember, no volcano mulching.

Fertilizing: That mulch you just added will add some organic material to your soil as it slowly breaks down, but an autumn fertilization can benefit your trees too. Unlike trees in the forest that have a natural supply of nutrients from fallen leaves and twigs, trees around our homes are usually deprived as we rake and clean up our yards. Adding a slow-release fertilizer in the fall helps provide a nutrient boost over the winter, can promote root growth, and better prepare your tree for Spring.

Watering: Water is still an essential part of your tree care plan, but as temperatures drop and trees begin to head into dormancy they don’t need as much water as is required in the hit summer months. If you have irrigation systems in your yard start to drop the frequency of watering. You can water up until the first freeze, but make sure soils are just a little damp and not soaked. Evergreens in particular will benefit from slow deep watering 1-2 times a week until the soil freezes. Winter winds and temperatures can desiccate the needles without an adequate supply of water.

Pruning: Now is a good time to prune out any dead, damaged, or diseased limbs in your trees. If you have access to hand saws and pole saws or pruners, you can remove smaller branches or those closer to the ground. Make sure you are making proper pruning cuts though, and if there are large limbs, those at heights, or you are just unsure of how to make a good cut enlist the help of a professional arborist.

Use of white tree guards can protect the trunk from temperature changes that cause damage (Joseph O’Brien, USDA Forest Service)

Trunk Damage: Sunscald or southwest damage occurs on young and/or thin barked trees in the winter. Wounds can occur between the south to southwest facing part of the trunk on sunny days in the winter as temperatures rise and suddenly drop. Over time these wounds can become quite large. Trees can also incur damage from deer during the rut. Bucks will scrape trees with their antlers, scraping off the bark and damaging the cambium. Both of these injuries can be reduced one younger trees by installing tree guards in the fall. Tree guards are plastic barriers you place around the main stem of the tree. I recommend using white corrugated drainage pipe that can be found at most home centers. You can make a cut lengthwise along the pipe for easy installation and make sure it has a large enough diameter to leave a space between it and the tree. Just remember to remove it come Spring.

Inspections: Visual inspections can be done year-round, but this time of the year it might be easier to see changes in your tree as leaves are falling and the canopy becomes more visible. From the ground up to the canopy, some of the things you’re looking for include fungal growth around the base of the tree, any sort of damage on the main stem or branches, premature leaf drop or color change, and branches that are dead, cracked, diseased, or seem weak. Any concerns you find are also great information to share with an ISA Certified arborist which can be found using the Trees Are Good website.

View the original article on the Purdue Landscape Report website: Help Your Trees Transition into Autumn.

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Resources:
Re-mulch Your Trees, Purdue Landscape Report
Find an Arborist video, Trees are Good-International Society of Arboriculture (ISA)
Trees and Storms: Understanding Damage, Risk and Recovery – Got Nature? Blog, Purdue Extension – FNR
Moist soil and rotten roots makes it easy for trees to come crashing down – Fox 59 News
Expert: Some storm damage can be easily prevented – Fox 59
Why Is My Tree Dying? – Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Tree Risk Management – Got Nature? Blog, Purdue Extension – FNR
Tree Pruning Essentials, Publication & Video, The Education Store
Mechanical Damage to Trees: Mowing and Maintenance Equipment – The Education Store
Trees and Electric Lines – The Education Store
Tree Defect Identification, The Education Store
Planting Your Tree, video, Purdue Extension
Tree Installation, The Education Store
Tree Wound and Healing, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Subscribe – Purdue Extension-FNR YouTube Channel

Ben McCallister, Urban Forestry Specialist
Purdue Forestry & Natural Resources

Simple Steps to Care for Your Tree: Mulching, Purdue Landscape Report

Posted on June 6th, 2025 in Forestry, Forests and Street Trees, Woodlands | No Comments »

Figure 1: Examples of volcano mulching (PLR)

Purdue Landscape Report: Tree care, in many cases, can be expensive if you require the assistance of an arborist for pruning or removals. Extreme weather events, characterized by extensive rain and wind, can cause damage to the canopy or, in worst-case scenarios, lead to tree failure. In cases of failures, weather is often the final push to already existing issues. One cause that can lead to decay, decline, and failure if applied incorrectly can also extend the life of your tree with proper application.

Mulch is the double-edged sword that can promote healthy growth by maintaining soil moisture and temperature through extreme heat, cold, and drought, enrich the soil in the critical root zone, maintain a safety area from mechanical damage from lawn care tools, and add a nice aesthetic.

Figure 2: Digging out and exposing the root flare (PLR)

But it can also cause decay through excess moisture to the root flare, damage from pests like mice and insects that can live in mulch, expose the tree to pathogens, and promote unnecessary root growth and/or stem girdling roots that cut off nutrient supply between the root system and the rest of the tree.

The application is the same if it’s the first time mulching a tree or a re-application. Add enough mulch so there is a 2–3-inch layer sloping away from the tree with at least a 3–5-foot radius around the stem (older, larger trees can benefit from larger mulch rings). No volcano mulching, make sure you also have around a 1-2-inch gap between the stem and the start of the mulch ring.

Figure 3: Creating a 1–2-inch space between the root flare and the mulch.

If you are reapplying mulch, first rake the old mulch to even the layer and mix some into the soil if possible. If your tree has already been mulched and has been volcano mulched, simply dig out the excess, exposing the root flare and creating that 1-2-inch gap between the stem and the mulch.

This simple act is relatively inexpensive, does not require a lot of time, and will help keep your tree healthy, extending its life. If you notice any other issues with your trees, hiring an ISA Certified arborist is the next step in managing your trees’ health. To find an arborist near you and verify credentials, use the link at Find an Arborist, Trees are Good, International Society of Arboriculture (ISA).

View the original article on the Purdue Landscape Report website: Simple Steps to Care for Your Tree: Mulching.