A wheelbarrow dumps mulch around the trunk of a tree in a front yard
(Image credit: ozgurcoskun)

Killing a tree is the farthest thing from a homeowner’s mind as they tend their beloved oaks and maples. Yet, tree pruning mistakes can be deadly for a tree, no matter how kindly intended, and we aren’t just talking about topping a tree. Incorrectly applied tree care can lead to tree stress and eventual death, including picking the wrong species for a site, improper mulching, and poor irrigation and fertilization practices.

Are you making serious mistakes with your trees? Read on for a list of seven tree care practices that may cause serious tree problems in the future.

1. Poor Species Choice

Selecting the right tree for the right place is essential. Consider both the mature height and width of any trees you may plant, as well as the preferred soil type and exposure. Select species and varieties suited to your area, picking those that are resistant to common insect and disease pests.

2. Poor Planting Practices

When you dig a planting hole, bigger is not necessarily better. A planting hole should be several times as wide as the root ball but no deeper than the root ball. Amend the soil first if it is heavy clay or sand and make sure that the first level of primary lateral roots are at or near the soil surface.

3. Restricting Trunk or Root Ball Growth

For a tree to grow, its roots must expand and its trunk enlarge. Some plants are sold with burlap or wire around the root ball or wire tags around the trunk. It is essential to remove these restrictions before planting. If you forget, the root ball will not be able to sustain a growing tree, and the tag might strangle the trunk growth.

4. Staking Incorrectly

To stake or not to stake? That is the question. Some experts advise against it but there are valid reasons for using this planting practice in areas of high winds if the site is not protected. Don’t try to eliminate all movement of the trunk or foliage, though. Rather, the goal is to prevent the root ball from rocking back and forth in the wind, damaging new roots. All staking material should be removed after a year.

5. Too Much/Too Little Water

In these times of drought, the danger of too little water for trees is well known. Every tree has different water needs and must have those needs met to thrive. Occasional deep watering is preferable to multiple superficial watering. Too much water can kill a tree faster than too little by suffocating the roots. More newly planted trees die from too much water than not enough, often in heavy clay soils.

6. Too Much Mulch

A layer of mulch is beneficial for trees since it protects tree roots from extreme weather conditions, prevents weed growth, and preserves soil moisture. In fact, mulching is often necessary. However, excessive mulching can hold in too much water around the roots. The layer of mulch shouldn’t be deeper than one inch (2.5 cm.) near the trunk but can be up to 4 inches (10 cm.) toward the outside.

7. Topping Trees

Cutting off the top of a ‘too tall' tree seems like a simple solution to the height problem. This is one of the worst tree-cutting mistakes you can make and a very easy way to kill a tree unintentionally. Trees should never, ever be topped. This practice creates an unattractive specimen and kills branches, shortening the tree’s life. Take care when selecting a tree to avoid planting tall trees under utility lines, awnings, or close to the premises.

Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.