Back 40: Spring cleaning for your forest

By Brad Bauer EBS Contributor

Spring brings warmer days and longer evenings, and working for Montana State University-Gallatin County Extension I have the joy of visiting with landowners around the region this time of year. During these visits we discuss many natural resource topics including the health of their forests.

In southwest Montana we have a two basic forest types, coniferous and deciduous. Coniferous forests are dominated by pines, firs, spruces and junipers, and are the primary forests in our region – when I visit a landowner’s property it is most often predominated by conifers. Our deciduous forests include aspens, willows and cottonwoods, and we occasionally visit a property with an aspen stand or a stream lined by willows.

Our native trees are tough and resilient to our long winters and short summers. However, as tough as they may be, it’s not uncommon to find individuals suffering from disease, insects or other stress. Spring is a great time to evaluate your trees and set them on a healthier path for the coming summer. Over the years, I’ve gathered a few tips and tricks that can help you prepare your forest for the coming summer.

Fuzzy white dots on the needles of spruce that can be scraped off with a fingernail are evidence of scale. Treatment includes pruning affected branches, or thinning affected trees.

When looking for ailments affecting conifer species, observe signs of:

Mountain pine beetle in lodgepole, limber and whitebark pines. Look for approximately quarter-sized bundles of pitch on the trunk that look like popcorn.

Scale in your spruce or pines. You’ll find brown or fuzzy white dots on the needles that can be scraped off with your figure nails.

Winter stress in your spruce or pines. Look for browning of needles on the south or west side of the tree.

Our native deciduous trees can also be host to a number of ailments. Keep an eye out for signs of damaged bark from wildlife feeding on, or rubbing your trees – especially young trees that have been hedged by foraging deer, elk and moose.

Winter stress is especially important on newly planted trees and shrubs. You might find die back of branches, discolored or cracking bark, or sloughing of surface bark to reveal dead tissue within the damaged area.

What do you do if you find any of these diseases, insects or stress in your trees? Unfortunately, there is no simple answer, because it depends on the tree species being impacted and the cause. However, there are some broad recommendations you can take.

Plant new trees at the proper depth. Plant so that the top of the root ball sits 1-2 inches above ground level. Planting too deep, or too shallow, stresses the trees and leaves them more susceptible to future problems.

Water newly planted trees for at least three years, or until well established. Watering is not limited exclusively to the summer months. During warm, snow-free periods of winter you should water your tree to a 2–3-inch soil depth, every couple of weeks.

Fence individuals or stands of young deciduous trees. High fencing or multi-layer fences can keep hungry wildlife from browsing on your establishing trees. Fence young trees until they are at least 6 feet tall.

Other methods for keeping your forested property healthy include pruning, or removing, trees with diseases or insects before they spread to the rest of your property or neighborhood. You can also thin stand of conifers to reduce the competition between individual trees for available water, nutrients and sunlight. This will help them be more resilient to predatory insects and diseases.

Thinning has the added benefit that if done properly, will not only leave you healthier trees but will reduce the risk of wildfire in your forest.

If wildfire mitigation around your property is a goal, consider following the National Fire Protection Association’s Firewise recommendations to create defensible/survivable space around your property. Firewise recommendations include creating a zone of little vegetation nearest your residence and reducing forest fuels as you work your way out from your home.

Finally, this spring visit with your neighbors, local landscapers, or give me a call to learn more about the health of the forest around you, and what you can do to keep your trees healthy and growing year round.

Brad Bauer is an MSU Extension–Gallatin County Natural Resource Extension Agent who focuses on natural resources management, education, and outreach. Call MSU Extension at (406) 388-3213 if you have questions about keeping your forested property healthy or stop by their office at 201 West Madison Avenue, Suite 300 in Belgrade.