News Release
May 21, 2007

Landscaping Tips: Successful tree planting strategies

By Tom Heald, extension educator, UW Cooperative Extension Service

It isn’t easy growing trees and shrubs in Wyoming – one look at the prairies suggests they aren’t in the cards!

But residents can successfully grow trees and shrubs and, to make the effort worthwhile, the University of Wyoming Cooperative Extension Service (UW CES) suggests the following planting strategies.

1. Location, location, location! This real estate term says it all when determining where to plant a tree or shrub.

Never plant trees too close to a home or outbuilding. No matter how small they are when planted, trees grow. They can interfere with the integrity of a foundation, and the long-term health of the tree can be compromised. Larger tree species should be planted at least 20 feet from a foundation, and all but the smallest shrubs should be kept at least 5 feet away.

It’s a good idea to measure the site before planting, and locate trees based on their mature size.

As corny as this sounds, look up before planting! If there are utility lines above the planting site, move the tree. In 10 years this will pay off.

Wind is a serious problem for most of Wyoming, and planting locations should be carefully considered so snow drifting won’t become an issue.

Before digging, call “One Call Wyoming” at (800) 849-2476 to have a representative visit the site to ensure underground utility or natural gas lines are not in the way.

2. Site preparation. Prepare the planting site by spading or rototilling an area at least two times the diameter of the root ball (example: if the root ball is 2 feet across then the area to be tilled will be 4 feet).

Dig the hole only as deep as to the top of the root crown – the area on a tree where the roots start to grow. Planting deeper may result in the death of the tree. Trees need water, nutrients, oxygen and good drainage to remain healthy. When root systems are buried too deep, less oxygen is available and often less water. In heavy clay soils, water may not drain properly, and deeply planted trees could succumb to root rot, a disease characterized by root decay.

3. Amend the soil? The research is fairly clear – don’t! Adding peat moss or aged manures into the planting soil mix provides no benefit to the trees. Research has shown that, in some cases, this can actually hurt a tree’s ability to survive and flourish. Getting the tree acclimated to the soil is important.

4. Remove all man-made items from the rootball. Things like wire, burlap and string need to be removed once the tree is in place but before backfilling begins. If left, these materials can cause severe root girdling as the tree matures.

5. When watering, think in thirds! After the tree is in the hole, backfill the hole with soil until it is about one-third full, gently pack the soil and then add water. This helps eliminate air pockets. Make sure all air pockets are filled in with water. Continue this process until completed, but don’t tamp the soil. Air pockets should be eliminated without packing the soil.

6. Fertilizing. It seems natural to add fertilizer to a newly planted tree. After all, that’s the common strategy in the garden. Adding fertilizer to a newly planted tree, however, can actually harm it! The tree needs to adapt to its new site, not produce a crop and, unlike a tomato plant that may get a full dose of fertilizer, a tree has many more years to grow and produce.

In general, one can begin to fertilize trees the year following planting, typically in late May or early June. A soil test done with the assistance of a UW CES office will help determine a tree’s fertilizer requirements. Contact information for offices is at http://ces.uwyo.edu/Counties.asp or in the white pages under county government.

7. Mulch the tree area. Next to proper planting depth, mulching is one of the most important steps to ensure trees and shrubs remain healthy.

Use coarse textured mulch like wood or bark chips, or rock. Usually, wood mulch is preferred but, in high-wind areas, pea gravel to fist-sized rocks may be needed.

Mulch does extraordinary things like allowing longer retention of soil moisture from the drying effects of the sun and wind. By applying mulch to the surface, water usage can be cut up to 75 percent.

Mulch reduces the compaction of soils around a tree allowing roots to easily grow into the soil. It keeps soils cooler in the summer and offers insulation in the winter, and it also helps to keep grass and weeds away from trees, eliminating potential damage caused by weed trimmers and lawn mowers.

Two to 4 inches of mulch is ideal, but do not mulch within 6 inches of the trunk; this will help avoid root rot.

8. Not all trees need staking, but if the tree is exposed to wind, use wide, belt-like straps, not rope or wire through a hose, to avoid damage. Allow the tree to sway slightly as this will promote strong roots.

9. Water newly planted trees frequently until the roots become established. To determine if watering should occur, poke you finger into the soil to see if it’s still moist.

For more tree plantings tips, see the UW CES bulletin Landscaping: Recommended Trees for Wyoming, B-1090, at http://ces.uwyo.edu/PUBS/B1090.pdf.

Contact: Robert Waggener, Editor
Phone: (307) 766-3571
E-mail: robertw@uwyo.edu

###