   Staking Young Trees - December 26, 2001 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Should you or should you not stake a newly planted tree? The answer depends on many factors. If the tree is in a commercial or park setting, then a tree may need staking for protection. Top-heavy trees, which are common in many container nurseries, require staking to prevent breakage and to strengthen the trunk. In moderately windy areas, a newly planted tree may need additional support simply to prevent it from blowing over. So, if trees need staking, why doesn't Mother Nature stake trees in the forest? To begin, lets review the natural history of a native tree. A seed of a suitable tree species germinates and develops into a sapling. For the first year or two, a wild-grown sapling puts most of its available energy into growing a substantial root system and resembles a shrub. This allows the tree to anchor and support itself while also exploiting a large volume of soil from which it can draw water and mineral nutrients. Once the root system is established, the tree can start to expand its energy collection system (leaves and branches) growing taller and wider. Where those branches grow, the energy produced by leaves above that point is directed back down that branch to increase the trunk girth in the area where that branch attaches to the trunk. Over time, lower branches are shaded by the upper branches, eventually causing the lower branches to die off. As this happens, the tree shifts from being a shrub to a tree. In nature, no stakes are needed. The top of the tree is supported by a well-developed root system and substantial trunk. Now, lets shift the setting to a residential landscape where, as always, the owner wants fast-growing, long-lived, trees to make summer shade and/or compliment the surrounding landscape. The nursery has several trees of suitable species to choose from and the owner purchases the appropriate trees for that landscape. What do these trees look like? They are in 5 or 15-gallon containers with a small stake tied directly to the trunk with horticultural tape. These trees have a root system that is confined to a very small space and no side branches below four or five feet above the soil level. Growers prune off the side branches to give the plant a tree-like appearance. These trees have small trunk diameters and must be staked to support the top and prevent trunk breakage. The nursery industry is not to blame for these spindly trees. Rather, consumer preferences perpetuate these cultural practices. The average consumer wants that tall, straight tree that looks like a miniature version of the adult. They do not recognize that a shorter, shrub-like tree with a stout trunk is a better choice than an "instant tree". Short, stout trees will still have their side branches and should not require staking. However, until consumers become educated, the trees available will reflect popular preferences and therefore require staking. First, a tree should be planted correctly (see Cooperative Extension Publication AZ1022 - Planting Guidelines: Container Trees and Shrubs). Begin by driving two wooden tree stakes on either side of the tree perpendicular to the direction of the prevailing winds. Make sure that stakes are driven at least six inches into undisturbed soil. To determine the height to place the ties, remove the nursery stake from the tree and hold the trunk with one hand a few inches above the ground. If the trunk leans over, move a few inches up the trunk and try again. Continue until you find the lowest point at which it will not bend. Place ties about six inches above this point. Attach only one tie to each stake. The old-fashioned "wire threaded through a piece of garden hose" tree tie system is outdated and can be harmful to the tree if left on too long. Rubber tree ties have been on the market for several years now as well. These have the advantage of stretching if they become too tight. However, they can still girdle the tree slightly if left untended. A new product, called ArborTie, is a polypropylene webbing that is tied around the tree using a unique knot and nailed or tied to the wooden stake. The knot prevents the webbing from tightening around the trunk. This is the best tree tying system that I have seen. Whichever tie system is used, it should have the ability to move slightly from side to side. This allows the trunk to build reaction wood, which strengthens the trunk with time. The tops of the stakes should be cut off below the canopy after tying to prevent rubbing on the lower branches. Inspect the stakes and ties periodically to prevent damage and assess the need for stakes. Generally, the stakes can be removed after on year. The underlying goals are to increase trunk diameter and promote root growth into the surrounding soil. Use care not to over-irrigate as this often limits root growth and allows the root ball to move with the trunk. By correctly planting and staking a young tree, you will be more successful in establishing young trees in your landscape. Better yet, watch for those stout trees that have had their side branches pruned from the trunk. The University of Arizona Cooperative Extension has publications and information on suitable tree species and plant selection. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/. |