Timberlines

By Shelly L. Van Landingham, Forester

Folks in Southeastern Colorado normally plant trees in the spring, which is perfectly fine. But fall is also a good time to plant trees, given a few guidelines.

A good rule of thumb for fall planting in SE CO is to finish planting by the end of October, so you are more than likely to avoid very cold, hard freezes. This is not to say that we never see cold, hard freezes in October—make sure to monitor the forecast before planting. The biggest question people have about fall planting is, "will freezing weather in the fall damage or kill a newly planted tree?". Usually, freezing weather that kills off leaves will not damage the tree unless the ground freezes. If the ground freezes soon after a tree is planted, root damage will probably occur and the tree will be harmed.

As a general rule, evergreens are at the highest risk when planted in the fall because their needles are exposed to the elements in the fall and winter. Evergreens give off water (transpiration) from their needles all winter. It is important that they are well watered in the fall before the ground freezes. Evergreens planted in the fall probably need a little more protection from the elements: if possible place wind protection around the tree (you can use wooden shingles for small trees).

Mulching will increase a new tree’s chance of survival. Fabric (water-permeable) weed barrier and woodchips are great mulching material. Mulching at least one foot beyond the tree’s rootball with a weed barrier square and/or woodchips will give the tree competition free space (from grass and weeds), and extra soil moisture to become established. The ends of the weed barrier can be held down with rocks or by mounding soil. Woodchips can be placed over the top of the weed barrier, providing even more protection for the tree. Make sure that woodchips are kept at least 2-5 inches from the base of the tree and are no deeper than 4 inches. Cut weed barrier back from the trunk as the tree grows. If this is not done, the tree will grow into the weed barrier, which will girdle the tree and eventually cause death.

Winter watering will increase a new tree’s chance of survival. Immediately after planting a tree, water it deeply, obtaining 12 inches of soil moisture. Check soil moisture weekly under mulch (throughout the year) to determine if water is needed.

Consider the following when planting a tree (any time of the year!). Avoid planting large tree species under utility lines. Determine how high the utility lines are and choose a small tree for planting. Consider the climate zone: Minimum temperature (between hardiness zones 4 and 5), and how much moisture we receive each year (averages between 12-14 inches). What is the light requirement of the tree: does it like more shade or full sun or a combination? What type of soil is on your property (the NRCS can help landowners determine their soil type). Consider insect and disease problems that are in this area (Colorado State Forest Service can help you with this) and what kinds of trees are more prone to problems. Are you looking for shade, aesthetics, windbreaks or screens, boundaries, or a combination of these factors. In looking at a potential location for a tree, consider future growth, size and shape of trees before planting.

Trees suggested for Southeastern Colorado. Deciduous (Larger): Hackberry, Western Catalpa, Liberty Elm, Lacebark Elm, Honeylocust, Kentucky Coffee Tree, Bur Oak, Linden Varieties, Japanese Pagoda Tree, Bigtooth (Wasatch) Maple, Mulberry varieties. Deciduous (Smaller): Crabapple and apple varieties, Hawthorn varieties, Goldenrain Tree, Ornamental Pears (preferably Aristocrat), Japanese Tree Lilac, Winterberry Euonymous, Purple Leaf Plum, Red Bud. Evergreens: Juniper varieties, Eastern Red Cedar, Ponderosa Pine, Austrian Pine, Colorado Blue Spruce, Mugo Pine (smaller). Please contact Shelly at 719.384.9087 for more tree and shrub types.

For more information visit the CSU Cooperative extension website: www.ext.colostate.edu/ptlk/1707.html Service In Action Sheet 1707 Fall Planting.