Tulsa trees bud early as unseasonably warm weather fluctuates
BY PHIL MULKINS World Action Line Editor
Wednesday, February 13, 2013
2/13/13 at 6:48 AM
Unseasonably warm weather tricked many Tulsa trees into thinking it was spring and time to "bud out." This worries tree experts that freezing temperatures will kill the buds and further endanger our drought-stricken trees.
Steve Grantham, certified arborist and operations director for Up With Trees, said Tuesday night's 29-degree low probably won't hard-freeze the buds but Friday night's 24 degrees might.
"This is something we deal with every three or four years, but with three years of drought it does have the potential for a cumulative effect," he said.
"A healthy tree can bud again after a hard freeze but, if these current buds freeze and die off, the trees can still go through a second line of buds but it's not going to be as prolific a leaf growth as the first line. The leaves will not grow as large and the food-making, energy-making capacity of the tree will not be as much as that of a healthy tree. A tree already damaged - by the Dec. 9-11, 2007, ice storm and three years of drought - can suffer a cumulative effect that brings the tree down.
Grantham said a healthy tree will be able to utilize other portions on its branching structure to generate second-line buds, in the real spring, to send out leaves. But a tree denied moisture by three years of trace rainfall, living off its vascular moisture storage to the point of dehydration, won't "have enough juice" to make the trip. It won't be able to grow leaves. The leaves won't be there to use sunlight, carbon dioxide and water to photosynthesize glucose - tree food - and the tree will starve to death.
Local trees hardest hit are the silver maples, the other maples, Bradford pears, any of the fruit trees and saucer magnolias; as they have shallower root systems and the intense heat dried these out more through evaporation of soil moisture and root moisture. It's also the maples that are leafing out early.
Master Gardener Dianne Nail said older trees compete with understory trees for moisture, making watering spikes and open, slow-flow hoses on the surface useful. They should run long enough for water to pond up or run off and then be moved. Perennials and shrubs must also be watered. Fescue and other broad-leaf grasses grow in tree shade and must also be kept watered or they will die and not be back in the fall, she said.
Mike Perkins, urban forester with the city's Parks & Recreation Department, said he also has seen the maple tree buds "plumping up," ahead of the other species, "but as long as the buds have not opened up they're still going to be protected by a cuticle coating that protects them to some extent. I saw an elm with open flower buds but not the leaf buds.
"So if the flower buds get damaged that's really not going to hurt the `vegetation' part of the tree. The best example is willows are the first tree to come out in the spring and usually well before any other tree. It's pretty standard for them to get nipped back and they form new growth and come right back. Now we are extremely early on lots of plants. Japanese maples often leaf out early and have 6 inches of growth when we get a hard freeze, killing back all this tender growth - but they eventually leaf back out."
Original Print Headline: Trees bud as temperatures fluctuate
Phil Mulkins 918-699-8888
Buds have already formed on trees in downtown Tulsa as more cold weather approaches. CORY YOUNG/Tulsa World