Learn how to keep your trees healthy and repair damage

With winter wind storms in the forecast, certified arborist and tree-risk assessor Dennis Tompkins has advice to give.

He plans to talk about keeping trees healthy and why they topple when he speaks Jan. 9 at the first lecture of the Snohomish County Master Gardener Foundation’s 12th annual Winter Speaker Series in Mukilteo.

Tompkins has helped many people decide if their trees are root-diseased and hazardous enough to be felled. He does tree assessments, appraisals, construction site monitoring and renovation pruning in south King and north Pierce counties.

He’s seen it all. And in many instances, he’s been able to save trees heavily damaged by winter storms.

Primarily, he enjoys telling people worried after a big storm to leave their trees alone.

“It’s so hard for an arborist like me to drive around and see the work of tree butchers,” Tompkins said. “There are some truly horrible pruning jobs out there.”

Aggressive pruning does trees absolutely no good, he said.

“First, never top a tree, and then prune and thin branches only selectively,” Tompkins said. “A butchered tree tries to re-establish the leaf surface and it sprouts like crazy. It’s a mess to deal with.”

A forest management graduate of the University of California at Berkeley, Tompkins has won many awards for his work and was a speaker at the Northwest Flower and Garden Show earlier this year.

In Mukilteo, he will cover tree root systems, common tree diseases and defects, how to prepare for storm season, how to deal with tree disputes with neighbors and what trees to plant for stability and low susceptibility to disease.

Tree failure in winter often happens because the soil is saturated and can’t hold the roots down when the wind begins to blow. Trees also fall down after suffering root rot for many years. Disease spreads through root-to-root contact.

“The surrounding trees might look healthy, but people need a trained eye to assess what is going on,” Tompkins said.

Trees susceptible to common root disease include Douglas fir. Western red cedar, on the other hand, is the native tree that seems most resistant, he said.

Tompkins cautions against “door-bell arborists” who work on commission and talk people into letting them cut down branches from older trees with the argument that thinned trees will let the wind blow through.

“There is no proof that it works, and if it is overdone, this pruning will stress the tree,” he said. “Way too many trees are cut down after storms. In the vast majority of assessments, I give trees a clean bill of health.”

One tree that Tompkins does like to prune is the Japanese maple.

“It’s a specialty of mine,” he said. “People like to see the exotic, twisty branches of these maples.”

Gale Fiege: 425-339-3427; gfiege@heraldnet.com. Twitter: @galefiege.

Winter Speaker Series

If you’re still looking for a Christmas gift for the gardener in your family, consider the Winter Speaker Series by the Snohomish County Master Gardener Foundation.

This popular series of talks by Northwest gardening experts is $85 for eight classes, each offering two hours of lecture, instruction and Q&A time. Sessions are 9:30 to 11:30 a.m. every other Friday, Jan. 9 through April 10, at Mukilteo Presbyterian Church, 4515 84th St. SW. Go to www.gardenlectures.com to register. For more information, call 425-357-6010. In some cases, speakers will have books and plants to sell after the session.

“We depend on ticket sales to fund our various teaching and mentoring programs (that help gardeners) throughout the county,” said Bernie Wojcik, a Washington State University master gardener.

Here’s the list of speakers, dates and lecture subjects:

• Dennis Tompkins, www.evergreen-arborist.com, Jan. 9, Are Your Trees Safe?
• Jessi Bloom, www.nwbloom.com, Jan. 23, Designing Your Oasis
• Edmonds Community College instructor Polly Hankin, Feb. 6, Hardscaping
• Far Reaches Farm, www.farreachesfarm.com, Feb. 20, Expanding Botanical Horizons
• Ciscoe Morris, www.ciscoe.com, March 6, A Tour of Ciscoe’s Garden
• Lisa Taylor, www.seattletilth.org, March 20, Vertical Gardening
• Riz Reyes, nextgenerationgardener.blogspot.com, March 27, Designing with Extraordinary Plants
• Dan Hinkley, danieljhinkley.com, April 10, Grasslike Plants for the Northwest