Trees at risk as summer drought continues

As northwest Missouri's dry spell continues, trees across Nodaway County are beginning to show signs of deep thirst.

While a bucket of water or a garden hose may seem like the obvious answer, Adam Stone, the arborist at Northwest Missouri State University, warns that making sure trees get enough water is not as simple as it seems.

"It is really important to water, but it is also really important to not over-water," Stone said. "Watering too fast causes it to run off, and the roots don’t get any moisture."

The most crucial part of the root system is the first six inches down, Stone said.

Making sure that part of the root system stays moist is a good step toward helping the tree survive.

He suggests watering slowly, no more than twice a week, to keep both native and ornamental trees and shrubs healthy.

One simple irrigation system requires merely drilling small holes in the side of a five-gallon bucket as close to the bottom as possible.

After filling the bucket the water should drain out slowly. Move the bucket around the tree to make sure the root system gets a good drink.

Drought can severely stress trees, but Stone said a lack of water can actually have benefits in the long run, including the spreading of root systems.

"You want the tree to stretch its roots out," Stone said. "It actually helps some of them out when they get stressed, they get stronger."

Trees native to this area, such as oaks and maples, have adapted to northwest Missouri's varied weather conditions and can usually handle the occasional dry summer. Ornamental and non-native trees are a different story, and slow watering can really make a difference.

Pruning should be avoided, though removing dead branches is usually OK.

Some trees in this area are beginning to show signs of thirst. These can include the shedding of leaves, leaves turning brown at the tips, and leaves fading from their norm;al deep green to a pale yellow.

Of course, the signs vary with the species, and Stone said many evergreens don't exhibit signs of dehydration until it is too late. Watch pines, spruces and firs closely, he advised.

Wilting at the leaf tips is another symptom of a drought-sick tree, Stone said, a sign that the tree is storing more water in its trunk.

"Wilting isn't necessarily a bad thing," Stone said. "A lot of plants wilt. It's a defense mechanism, and trees can bounce back. It can be caused just by heat, but it is a sign that they need water. Again, do not over-water."

Aside from watering, mulch can have a good effect on tree health in dry weather.

Stone suggests using hardwood mulch, such as cedar. It is important that mulch not touch the base of the tree where it can cause the bark to rot.

"You want doughnuts, not volcanoes," said Stone, referring to the shape of the mulch ring. "Keep it one or two inches from the base and four inches deep."

The drought is also causing problems with disease and insects, including spider mites on evergreens such as spruce trees. To cut down on these problems, Stone suggested hosing down the tree during the early morning hours.

Another option is chemicals. Stone said that if you suspect trees or shrubs of having an insect problem, the best option is to call a licensed specialist. If you don't know one, ask for referrals at a local greenhouse or plant store.

Carolyn Schroeder, president of the Maryville Garden Club, said that special care should be given to perennials and garden vegetables. Also plants with shallow roots, such as strawberries, should be watered frequently.

She said that young plants are the most vulnerable, and that even though the plants may look like it is to late to save them, do not hesitate to try.

"Some of them may not be looking their best right now," Schroeder said. "But care now will keep them alive for the future."