Don't pile 'mulch mountains' on tree trunks

December 04, 2008|By JEFF RUGG/Creators Syndicate

Q: We recently had a couple of trees planted in our yard by a company. When they were done, they did not stake the trees. My husband called them and they said that they don't stake trees anymore. We want an outside opinion and were wondering what you think they should do. And one other thing: They only put down a few inches of mulch. How much is proper?

A: Well, my suspicion is that they are right. If the trees were growing in the proper-sized container or had a properly sized root ball for a balled and burlapped tree, and they were planted correctly, then they should not need to be staked. If they were bare-root trees that didn't come with soil around the roots, then they probably do need to be staked.

Many trees have been staked improperly over the years, causing more damage than benefits. Quite often the wires or rope were tied too tightly. Any tree that has an artificial support will tend to grow taller without growing a sturdy thick trunk. It will also not grow as many roots, since they are not needed to hold it into the ground. When the supporting wires and stakes are removed, the tree can't support itself and it breaks in half or flops over to the ground.


If a tree is to be staked, it should be tied so that it can sway all the way from the ground to the top. It should be able to support itself, but have the stakes and wires available to keep it from blowing over. The stakes should be removed when the roots take hold and it can stay in the ground and stand up on its own.

For a small tree, especially if it is bare root, a single stake is fine. It should be driven into the hole before the tree is placed. Set the stake slightly off-center. Its final height should be about three-fourths the height of the tree. Plant the tree. Loop the wires around the tree and stake using a covering to protect the bark from the wire. A strap of cloth is better than the wire at protecting the tree. Place one strap near the top of the stake and another one at the lowest branch.

Plant a container-grown, small ball or burlapped tree as normal. If staking is necessary, two stakes should be driven in solid ground next to the hole and opposite each other. The top of the stake should be about two-thirds the height of the tree. The straps should be tied at the top of the stakes and looped around the tree.

Very large balled and burlapped trees can be protected from blowing over by using three guy wires. In this case, stakes are secured in the ground outside the root ball. Wires are run to the tree at about a 45-degree angle and loosely secured around the trunk.

In no case are the stakes and wires meant to be holding the tree in place or pulling it up to make it straight; they are just there to prevent the tree from blowing over. They must not be tight.

For trees planted in the fall, most guy wires and stakes can be removed by the Fourth of July. Trees planted in the spring can have them removed in the fall. Tree growth will be reduced if they are left in place longer than a year.

Let's discuss mulch on tree plantings. Right now, much of the country is going through a really bad phase of improperly installed mulch around trees. The correct amount is a 2- to 3-inch layer covering the root ball, and possibly a little bit wider. There should be no mulch on the tree trunk. The proper shape for the mulch is a doughnut-shaped ring, not a mountainous pile. A thin layer of mulch helps keep the root area moist, while also allowing air into the soil. It helps prevent weeds, and as it decays, it provides more organic matter to the soil, if it is organic mulch.

It should never, ever be piled up on the trunk of the tree. Please read that last sentence over again and again. Memorize it. Whenever you see mountains of mulch piled on the trunk of a tree, you should be saddened. It is ugly and is slowly killing the tree.

There is absolutely no excuse for this bad practice. Wherever you see it done by a company that is getting paid to do it, you know that they are unprofessional. Apparently, such companies are getting paid by how much they install and not by doing the job right. They should pay for the replacement of the trees that will die under their care, and they should remove the mulch down to the proper level on their own dime.

This bad practice causes several problems. Tree trunks are supposed to be growing above the ground, not buried in it. They may last a few years, but they will rot and get diseased from being buried this way. All mulch should be removed from the trunks of all trees.

The roots of plants need air in the soil. Being buried by huge piles of mulch (even as little as 6 inches) will suffocate roots. Some trees have the ability to send out roots into the mulch mound as though it were a soil layer. Unfortunately, the mulch dries out too fast and these roots die, wasting growth that would have been good if it had been in the ground and spreading out away from the tree rather than being stuck in the mulch pile.

Mulch mountains hide mice, voles and insects that eat tree trunks. Without the mulch piled on the tree, the rodents and termites would be more exposed and less likely to kill the tree by eating the bark.

Thick piles of mulch are compost piles that are not getting turned. Therefore, they have anaerobic breakdown of the organic matter. This leads to the release of toxic and smelly chemicals that kill roots.

It sounds to me like you picked a reputable and knowledgeable tree company and that they did the proper job.

E-mail questions to Jeff Rugg, Kendall County unit educator, University of Illinois Extension at

Copyright 2008 Creators Syndicate Inc.

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