Young trees may need both support and protection. You can use stakes to hold up their trunks or anchor their roots and to protect them from damage. If a tree is planted in an exposed area, it may need protection — especially from lawn mowers — until its bark has grown thick enough to protect it. Older trees that have been transplanted to a new location may need support while their roots grow into the surrounding soil. And the trunks of trees grown in containers may not be able to support the weight of their tops without support.
Trees With Weak Trunks
Trees that are allowed to grow in one spot from seedlings seldom need support at any point in their lives. Many nursery trees, however, are pruned to look like miniature versions of mature trees, with all the branches coming from the top third of the trunk and the bottom two-thirds bare. The lack of branches on the lower portion keeps the trunk from expanding as it should. Then, to make the trunk nice and straight, it is tightly tied to a stake from the time it is very small. In addition, the trees are often grown packed tightly together. This is done partly to save precious space in the nursery, but also to make the trees grow taller than they would if the sun could reach all their leaves.
All these practices lead to a slim, weak trunk that cannot support the weight of the top of the tree. When a newly purchased tree is cut from its stake, it usually flops to one side, sometimes far enough to touch the ground. The tree must be supported in the landscape until the trunk grows strong enough to hold itself upright.
But this support should be seen as a temporary crutch, not as a permanent aid. One aim in staking the tree should be to encourage the trunk to grow strong. This can be done in two ways. One way is to allow temporary branches to grow from the trunk. These can be headed back to keep them small until they are no longer needed. These branches encourage the trunk to grow in girth and to grow thicker at the base, tapering toward the top. This taper makes the trunk strongest where it needs strength. The branches will also help to protect the trunk while its bark is thin by keeping animals and people away from it.
The other way to encourage the trunk to grow strong is to allow it to move in the wind. Tie the tree to the stake at only one point, as low as possible, so that it flexes and bends in the wind. This bending stresses the trunk, causing it to grow thicker and stronger where it is stressed, much as exercising your muscles make them larger and stronger. If the trunk is so weak that it will not remain upright when tied at only one point, tie it at several points to a flexible pole, such as a 1/8-inch iron rod, then tie this pole to the stake at one point. The pole will support the trunk but still allow it to bend.
Staking to Support the Trunk
Place two stakes on opposite sides of the tree, at right angles to the prevailing wind. If you have to use only one stake, place it between the plant and the prevailing wind. Using two stakes, both with ties around the trunk, helps keep the trunk from rubbing against its support. The stakes should be only tall enough to hold the tree upright. Tie the tree only at one level.
Locate the ties on the tree as low as possible to allow it to move in the wind and build up its strength. Find the right point to tie the tree by holding the tree with one hand and bending the top over. Make the tie at the lowest spot that keeps the tree upright.
The stakes should penetrate 18 inches into the ground; add that 18 inches to the distance between the ground and the tie point when you calculate the total stake length. Insert the stakes so they press tightly against (but don’t go through) the root ball.
Place the ties as close as possible to the tops of the stakes to prevent rubbing against the trunk. If the stakes are too long, cut them off a couple of inches above the ties. If you are using a single stake, make the tie in a figure-8 pattern so the trunk is less likely to rub the stake. Use rubber, nylon webbing, polyethylene tape, tire cording, or some other suitable tie material. Wire, even when covered with garden hose, harms the trunk if left on too long. Use rustproof tacks or staples to hold the tie firmly on the stake.
Exceptionally spindly tree trunks the won’t support the tree even with a tie, may be further supported by tying a spring steel wire to the trunk with plastic ties. Wrap the top of the wire with plastic to keep it from gouging the trunk.
A cross brace made of a 1×4 board at the bottom of the stakes will help keep the stakes upright in extremely windy locations.
Trees With Weak Root Systems
Often, the trunk is strong enough to support the tree but the root system is too small to hold it upright. This is especially the case in a windy location. If the wind is not too strong, thinning out the top of the tree so that the wind doesn’t have so much to push on will substitute for staking. If staking is necessary, a few short, stout stakes will brace it until its roots grow into the native soil and anchor it. Drive 3 stakes equidistant around the tree and about 1/3 as high as the tree. Tie lines from the tops of the stakes to the trunk to support the tree. You can also use guy lines to support trees. See below for instructions.
Or, if you are using three stakes to protect it, simply use stronger and longer stakes and tie the tree to them about one-third the distance up the trunk.
Here, too, the staking is a temporary measure. Your aim is to help the tree root quickly so that the bracing can be removed. Bending stresses the roots as well as the trunk, causing them to grow thicker and stronger. To allow the roots to be stressed, tie the tree to the stake with flexible ties. These can be nylon ropes or wire rope with compression springs in them. Compression springs are available from hardware stores; they allow the wire to stretch a little, then become firm.
Another thing you can do to help the roots grow strong is to feed and water the tree correctly. If you live in an arid climate, check the root ball regularly after it is planted, and water whenever it is only slightly moist. You will find that the tree requires frequent watering for a few weeks after planting, but then the need for water drops. This happens when the roots begin to spread through the soil so that they are getting water from a larger soil volume. At this point, gradually change your watering practices so that you water deeply and thoroughly but infrequently. Allowing the soil to dry out somewhat between waterings encourages the roots to explore more widely and deeply for water.
Using Guy Lines to Support Large Trees
Large trees transplanted into a landscape may need support for the first year to keep them from blowing over. But stakes can’t provide enough support for large trees. Use three guy lines instead, spaced equidistant from each other and 5 to 10 feet from the trunk of the tree. Nylon webbing or nylon rope makes excellent guy lines. If the guy lines are not readily visible, tie rags to them or run the lines through PVC pipe to avoid tripping hazards. Attach the lines to a collar, made of a soft material such as 3-inch nylon webbing, around the tree’s trunk.
If inflexible material, such as wire or steel cable, is used, add a compression spring to each wire to provide flexibility and allow the trunk to move in the wind. Attach the guy lines to 2×2 or 2×4 stakes or to pins or sticks buried in the ground. In lawns, drive short iron pipes flush to the ground at right angles to the guy line. Attach the line to a pin such as a long eye-bolt and drop the pin into the pipe. The pin can be easily removed for mowing.
Trees That Need Protection
Stakes can serve a third function for young trees: they can protect the trunk. Until the bark grows thick and tough, it is susceptible to tearing. Since the sap flow is through the thin tissue between the bark and the wood, a tear in the bark reduces the flow of sap, stunting the top of the tree to some extent. Three or four conspicuous stakes around the trunk keep lawn mowers and tricycles from endangering it.
Staking to Protect a Tree Trunk
Drive 3 or 4 short (about 1 foot long) stakes 6 inches into the ground. Space the stakes a foot away from the tree and equidistant from each other. The aboveground part of the stake should be clearly visible. join the stakes with nylon rope, or twine with pieces of cloth tied to it to make it visible. Another approach for maximum visibility is to run a wire through a plastic pipe between the stakes.
Tree trunks can also be protected from lawnmowers in other ways. See Trees in the Lawn for some ideas.
Remove the Stakes
One of the most frequent, and most visible, errors in landscaping is to forget about stakes and leave them until they rot. Stakes are like crutches — they are temporary support meant to aid the tree only until it can stand on its own. They can harm the tree if used too long. Remove them as soon as the tree is strong enough to support itself.