Experts say saving your tornado-ravaged yard starts with protecting the soil and damaged trees

By Mary Jo Modica
Special to The Tuscaloosa News

Published: Sunday, June 19, 2011 at 12:37 p.m.

Last Modified: Sunday, June 19, 2011 at 12:37 p.m.

Rob Crawford is a man with a mission. A member of the International Society of Arborists and a certified consulting arborist specializing in evaluating and preserving large trees, Crawford is a veteran of urban reforestation in post-Katrina Mississippi. He visited Tuscaloosa in mid-May to consult on a restoration plan for the tornado-impacted areas of Hurricane Creek.

One of his goals is to share his experience with urban reforestation.

“As I was driving through town, I realized that this was like no tornado I had ever encountered. The devastation was more like what I had experienced in Mississippi after Katrina. New Orleans received most of its damage from flooding but Mississippi took a direct hit from the wind. I realized that I wanted to share what we learned — the things that went well and those that turned out to be mistakes,” Crawford said.

His advice for homeowners is centered first on protecting and building the soil. To protect the soil and the roots of any trees still remaining and to prepare the ground for future tree and shrub plantings, it is important to keep heavy machinery out of the area or at least off the roots. This will help to avoid compacting the soil and unintentionally removing topsoil while removing tree debris.

“When repairing the hardscape in your yard, avoid cutting into a tree’s roots with an irrigation system or sealing off the roots from water and air by placing a driveway or sidewalk over a portion of the root system,” he advised. “This only serves to weaken the tree.

“The ecosystem that our trees and plants live in begins with a healthy habitat for soil microbes. Mulching creates that habitat. The microbes digest particles of debris making nutrients available to the trees. The best way to ‘feed’ the microbes is with mulch.” 

Rob Crawford is a man with a mission. A member of the International Society of Arborists and a certified consulting arborist specializing in evaluating and preserving large trees, Crawford is a veteran of urban reforestation in post-Katrina Mississippi. He visited Tuscaloosa in mid-May to consult on a restoration plan for the tornado-impacted areas of Hurricane Creek.

One of his goals is to share his experience with urban reforestation.

“As I was driving through town, I realized that this was like no tornado I had ever encountered. The devastation was more like what I had experienced in Mississippi after Katrina. New Orleans received most of its damage from flooding but Mississippi took a direct hit from the wind. I realized that I wanted to share what we learned — the things that went well and those that turned out to be mistakes,” Crawford said.

His advice for homeowners is centered first on protecting and building the soil. To protect the soil and the roots of any trees still remaining and to prepare the ground for future tree and shrub plantings, it is important to keep heavy machinery out of the area or at least off the roots. This will help to avoid compacting the soil and unintentionally removing topsoil while removing tree debris.

“When repairing the hardscape in your yard, avoid cutting into a tree’s roots with an irrigation system or sealing off the roots from water and air by placing a driveway or sidewalk over a portion of the root system,” he advised. “This only serves to weaken the tree.

“The ecosystem that our trees and plants live in begins with a healthy habitat for soil microbes. Mulching creates that habitat. The microbes digest particles of debris making nutrients available to the trees. The best way to ‘feed’ the microbes is with mulch.”

The roots of trees still standing after the storm have been suddenly exposed to the drying effects of direct sunlight. Crawford suggests a 4- to 6-inch layer of mulch to keep the newly exposed soil cool, to add organic matter to the soil and to give trees’ feeder roots a sponge-like, air-filled medium to grow into.

When asked what mulch would be the best for the trees, Crawford recommends “shredded leaves and small branches” but discourages using freshly chipped material.

“Fresh bark, chips and sawdust tie up nitrogen in the soil as they decay,” he said. “Allow chips to compost before using them. Adding a handful of nitrogen fertilizer to the compost will speed the process along.”

He noted that “most trees don’t have a tap root but a root plate. A tree’s root plate is an extensive web of small roots that extends to the drip line of the tree (the edge of its branches), which is often 10 feet or more beyond the trunk. To adequately feed the soil, and in turn the trees and shrubs, it is necessary to apply mulch that far out.”

He advises homeowners not to “get caught up in tree phobia and cut down trees near houses. Any trees still standing are probably strong and healthy. Give them a thick layer of mulch. It is the neglected trees that will become problems.”

He also counsels patience. “It’s human nature to want to make things right, right now. But planting trees and shrubs in the heat of summer is stressful to the plants and requires a great deal of water to get them through to cooler weather.”

Lastly, Crawford encourages people to manage their wood debris wisely. “Getting rid of small branches and limbs may seem like a good idea now, but in the fall you will need to mulch newly planted trees. One of the biggest mistakes we made after Katrina was hauling away all the wood. When fall planting time came, it cost the communities thousands of dollars to mulch the new trees.”