Stake Trees Properly to Prevent Damage

Staking is, in the minds of many, an essential component of the tree planting process… but have you ever thought about why we stake trees? What are we trying to accomplish? Is it always necessary? Are our staking methods actually a benefit to the tree, or are our good intentions causing greater harm?

Why to Stake

A new landscape tree has a fairly small root ball, relative to the trunk height or canopy fullness that it supports… Sometimes so much so that it may need a little extra support to stabilize its root system as new roots become established in the surrounding soil. In addition, a tree planted in an exposed, windy location can benefit from stakes to prevent it from uprooting in the wind. At the same time, many trees can hold themselves upright without this additional support, especially with proper planting and when placed in protected locations. 
tree that was staked too tightly or too long
According to the International Society of Arboriculture, “Studies have shown that trees estab¬lish more quickly and develop stronger trunk and root systems if they are not staked at the time of planting.” It is best to leave a tree without stakes, unless it just really needs the extra support.

A common misconception is that a tree needs stakes to keep the trunk from bending over, which is rarely the case unless the tree just has a flimsy trunk or a loose root ball. We also often see people apply stakes, tied rigidly along a length of trunk, in order to direct the growth of a tree. While this can help in the short term with young trees, it can also cause harm. 

Here are some tips for maximizing the benefits of tree stakes, without damaging the tree in the process.

Attach Stakes Loosely

Newly planted trees may need stakes to keep the wind or the weight of the canopy from causing them to uproot and fall over, but attaching stakes rigidly to the trunk can have the opposite of the intended effect. When a tree is not given the flexibility to sway naturally, it fails to develop trunk taper, or strong and flexible wood growth along its trunk. If a tree is not accustomed to any movement, when the stakes are removed the trunk is weak and not prepared to face nature’s forces. Rigidly staked trees will often flop over after stakes are removed (such as in the photo above), or even break in half in a strong wind rather than swaying and recoiling the way trees are designed to do.

When attaching staking materials, give the tree a little push. If it has some give to move in the wind, this is the correct tension. If the tree won’t budge, you might want to loosen the ties a little bit.

Use the Right Materials

Many staking materials tend to rub against or dig into bark tissue and cause damage that can severely compromise a tree’s condition. Such materials that are discouraged from use include bare wire, rope, and garden hose. Urban Forestry recommends using flat nylon webbing in securing stakes to a tree for best results. The flexibility of the material and lightweight, soft, broad surface area spread across the bark reduces the risk for girdling/rubbing. When attaching staking materials to the trunk, create a loose loop so that the material is not too tight around the bark.

Let the Tree Grow

With young trees, branches do not always grow in the direction we want, or a leader may have a lean to it. The same logic for not attaching staking materials too tightly applies to recommendations against correcting a lean by rigidly splinting the trunk with a stake. Leaning trunks will normally straighten up as they grow, and over time as the trunk increases in size the original lean will be less noticeable. The best way to avoid crooked branches or bent trunks is to select a specimen that has good structure to begin with, and be sure to check for leans during the planting process. Apply water to the hole when it is partially backfilled to help the soil settle in around the root ball. This can help to prevent a lean from developing later as the tree settles, and can also help to anchor the root ball better. Bent/crooked branches may often be addressed through pruning, by selecting the most favorable trunk leader or removing branches with poor form.

When purchasing a tree from a nursery, bamboo stakes are often secured to the trunk with tape in order to maintain a straight main leader in the tree. It is generally recommended to remove these materials at the time of planting if the trunk is not too flimsy to stand upright. Leaving the bamboo on the tree can prevent the development of trunk taper, and the tightly attached materials can also girdle the trunk as it grows.

When attaching staking materials, loop them loosely around a branch union on the lower half of the tree. Attaching materials too high on the trunk can restrict movement or cause the canopy to bend down toward the stake.
Trunk girdling caused by staking materials

Take Stakes Off Sooner Than Later

All the benefits of tree stakes can be undone by simply leaving them attached for too long. As a trunk grows in diameter, it will grow around and be girdled by staking materials that encircle it (see photo to left). Trees that are restricted in movement by stakes will develop less trunk taper than trees that are free to sway in the wind, and will thus have weaker tissue and greater susceptibility to breakage or bending. It’s best to remove staking materials as soon as the root ball is anchored enough to stand up without them (usually after about one year), so that the trunk may begin building optimal taper. 

Overall, Urban Forestry recommends only staking trees when it is really necessary, using soft and flexible materials tied loosely enough to encourage natural movement in the trunk, and removing them as soon as the root ball is anchored enough to support itself. In the end, pay attention to how stakes are affecting your tree, and take action if you notice girdling, rubbing, or restricted movement.

View more topics from the Summer 2017 issue of Edmond Tree Mail