Top 10 tips for long-living trees

NEVADA, Mo. —Trees, like people, have a life span. They live, they flourish, they die. University of Missouri Extension agronomy specialist Pat Miller offers her Top 10 practices for prolonging the life of your tree.

1. Don’t plant too deep

Planting too deeply can cause roots to encircle the tree and eventually girdle and choke it, Miller says. “This invisible killer often doesn’t cause a problem for many years.”

Dig the hole only as deep as the soil ball. For more information, see the MU Extension guide “How to Plant a Tree” (G6850), available for free download at www.extension.missouri.edu/G6850.

2. Pick a site suited to the tree

Plant trees where roots can grow unhindered. Trees with sidewalks, houses and streets covering their roots will struggle to survive, Miller says. Roots need water and air.

Some trees do best in partial shade while others may prefer full sunlight, she notes. The MU Extension publication series “Selecting Landscape Plants” offers tips on choosing the right trees for your yard. Go to www.extension.missouri.edu/TreesShrubs.

3. Don’t burn brush or leaves too close to your tree

“A fire near the trunk can damage the tree’s vascular system,” Miller says. “Because heat rises, a fire built out from the trunk but still under the canopy of the tree will damage the upper branches.”

4. Use proper pruning techniques

“Topping” a tree—drastically cutting back its main branches—can greatly shorten the life of a tree and create flushes of weak growth at the branch ends.

Proper pruning and training of a young tree will prevent narrow crotches, which leave trees vulnerable to storm damage. “Good pruning techniques also will promote healing of wounds and deter disease,” Miller says.

For more information, see the MU Extension guide “Pruning and Care of Shade Trees” (G6866) at www.extension.missouri.edu/G6866.

5. Don’t let trees get too thirsty

While healthy, well-established trees can usually endure a dry spell with no ill effects, an extended drought like the one that parched the Midwest last summer can deplete a tree’s supply of subsoil moisture.

“While it is often believed that large trees have huge, deep root systems, most of the roots that take up water and nutrients are in the top 18 inches,” she says.

Drip irrigation can help you conserve water while reducing stress on trees. Learn more from “Irrigating Trees and Shrubs During Summer Drought” (G6879) at www.extension.missouri.edu/G6879.

6. Remove strings, wire or plastic from the tree before planting

Over time, these can girdle the tree, causing it to die, Miller says.

7. Avoid compacting root zone soil

“Compaction in the tree root zone from construction equipment reduces the ability of the soil to hold air and water,” she says. “Often people build a house on a wooded lot only to find that years later the construction process has caused the trees to slowly die.”

Before construction starts, check out the MU Extension guide “Preventing Construction Damage to Trees” (G6885) at www.extension.missouri.edu/G6885.

8. Don’t crowd the tree

Raised beds around a tree can suffocate the roots and damage the trunk, Miller says. Do not change the soil level around a tree if possible.

9. Easy on the mulch

Mulch should be applied in a 2- to 3-inch layer in the drip line area around the tree. Mulch should not touch the bark. “Think mulch doughnuts, not volcanoes,” Miller says.

10. No weed eaters

“Ban weed eaters from your possession,” she says. “ O.K., maybe you can own one, but never let it be used near a young tree. The vascular system of a young tree is just under the thin bark layer. If the vascular system layer is damaged, it can girdle the tree and kill it. Mower decks can do similar damage.”

For more information on lawn and garden topics, go to www.extension.missouri.edu/LawnGardenNews or contact your local MU Extension center.