5 ways you may be harming your trees

Are you harming your trees? Here are 5 ways you might be.

Trees are generally hearty, robust plants. They can withstand and even continue to thrive through many different adverse conditions. Yet you may be doing or not doing things that could be harming your trees without realizing it. 

Here are five fictions about ways that people often care for their trees and the facts behind how these activities may actually be harming them.

1. Covering or building over trees to hide ugly roots is OK

You have a tree with large, gnarled, unsightly roots that stick out of the ground. You’d prefer to not have to look at them, mow or trim around them, or catch your foot on them when walking through your yard. It’s fine to build a structure over them or cover them with something so you don’t have to look at or trip over them.

Fact: The answer to this varies, but generally this should be avoided. While it might be OK to cover roots with a deck, boardwalk, or similar structure, be sure to give the roots clearance to continue growing. Never cover roots with concrete or cement. This prevents roots from growing larger and longer, which is necessary as the tree matures. Covering over roots with cement or concrete will stifle the tree’s ability to find the increased nutrients and water it needs. Also, roots will often eventually push through concrete or cement, resulting in cracking or heaving from beneath.

1. Planting trees close to each other won’t affect them

You’d like to plant some trees close together so you can create your own mini-forest, a clump of trees for privacy or shade, or just because you like a particular tree variety.

Fact: Trees need their space. Planting trees very near each other will force them to compete for resources, like nutrients and water from the soil below for their roots and sunlight from above for their leaves. Also, their roots can become intertwined and obstruct each other. While your trees may continue to grow, typically none of them will thrive in these conditions, so their growth will be slow or very limited.

1. Using screws, staples, or nails in a tree doesn’t harm them

You are planning to build a makeshift ladder from 2x4s or planks nailed to your tree’s trunk for your kids to climb into your backyard tree. Or perhaps you want to hang a sign, bird feeder, or similar item from your tree, so you secure it with screws or large staples.

Fact: As with covering over a tree’s roots, this one depends. You should never extensively drill into a tree. However, mature, healthy trees can often withstand very minor drilling, small nails, or staples. Yet trees that are weak due to drought, disease, pests, or other reasons, and trees with thin bark should not be nailed or drilled.

1. Spreading mulch too close to a tree’s trunk is good

You’re planning to lay a nice thick bed of mulch around the foot of your tree to help give your landscaping a better appearance. Plus you’ve also heard that mulch helps hold moisture in and spread it out, as well as keep weeds down, which is better for your tree.

Fact: A thick layer of mulch does hold in as well as create moisture, but this often results in decay beneath it. Decay weakens bark and roots, which will compromise the tree’s strong foundation, which, if severe enough, can even lead to the tree being uprooted and falling over in high winds, which will not only kill the tree but could damage your property or cause harm to people.

1. Girdling a fruit tree helps it yield more fruit

You want to encourage your fruit trees to yield more fruit, so you “girdle” them by removing a thin ring of bark from their trunk. 

Fact: As you’ve probably guessed by now, girdling is certainly on the list of actions that can seriously harm or even kill your trees. Removing bark is a critical blow to the tree: without bark, the tree’s flow of critical nutrients from the leaves down to the roots is interrupted. Cutting the roots off from the tree’s food source can cripple and often kill a tree.