Trees under stress from lack of water, ice storms, wind damage

SIKESTON, Mo. -- The last several years have been hard on trees.

Any time there is a period of dry weather, there are some landscapers who spend a lot of time on their lawns but take their trees for granted, according to David Bizzell of Bizzell Lawn Care and Nursery.

Things are now beyond just being a bit dry. Bizzell said the U.S. Department of Agriculture is listing the area as being in a drought.

"We've had a lack of rainfall really since the middle of May," he said. "We need to deep water these trees until we get adequate rainfall. The recent rainfall only penetrated about an inch or an inch and a half. We're not finding moisture down at four feet when we're digging."

The damage to lawns is obvious, but those unfamiliar with trees and shrubs may not realize those plants are also suffering from the drought, especially since they have endured some severe weather over the last few years.

Bizzell said it all started with the strong winds from Hurricane Ike in September 2008.

"We had a lot of storm damage," he said. "Then we had the killing freeze in late spring of 2008. That killed off leaves and then the trees had to use stored reserves in the root system to push the secondary buds. That taxed the trees heavily."

Before they had a chance to fully recover, the January 2009 ice storm hit trees and shrubs again, and hard.

"We're still seeing the effects of it," Bizzell said. "It's called a 'mortality spiral.' What you look at is one or more catastrophic events that make a tree draw on its reserves puts a tree under undue stress."

Bizzell said fewer leaves means a tree or shrub has a diminished ability for photosynthesis.

"With a reduction of photosynthesis, they don't build stored reserves back. So every event after that has the possibility of killing the tree or shrub," he said. "If your trees are already under stress due to the drought and all the past occurrences, you will have a greater chance of losing those trees due to a lack of moisture."

And replacing a lost tree can take a long time.

Even starting from bare earth, "it takes about two to three years to get a healthy lawn established," Bizzell said. "But with a hardwood tree you are looking at 12 to 15 years before you are beginning to see the benefits of shade."

Softer wood trees, such as tulip poplars, mature a bit faster and can provide shade benefits after eight to 10 years, he said. It can take 20 years for a tree to grow to a height of 40 feet, he said.

Bizzell recommended area residents who have a tree in their yard should place a sprinkler under the tree and water it two or three times per week, depending on the size of the tree and the type of soil.

"For large shade tree, you could run that sprinkler an hour and half three times a week for the next few weeks," he said. "That will help to hydrate the root cells because they tend to collapse when they dehydrate, just like a human."

Bizzell said the largest percentage of a tree's roots are in the top 18 inches of soil.

"Those are the feeder roots that draw in the essential elements and moisture," he said.

Mueller said while it is late in the year, some trees may need some trimming to get rid of weaker branches so they aren't further stressed by losing them to a winter storm.

"I still have some pruning I have to do on my dogwoods," he said.

Mueller cautioned against trimming too severely this time of year, however.

"You don't want to have a lot of scarring on the tree going into winter," he said, as trees mend themselves better in warm weather.

Bizzell recommended fertilizing trees in the late winter, preferably in February.

"You need to do it very cautiously under supervision so you don't burn the root system with the application," Bizzell said. "And make sure you are supplying that moisture all the way into winter so the ground doesn't freeze up with the roots being dry."