By Charly SHELTON

The drought may be over and the hills may be green, but the lasting effects of a five-year water shortage can still be seen in the trees of California. With reports of huge trees toppling over becoming more and more commonplace, it is safe to say that we are not done losing plant life yet.

“[The trees] become stressed and in many cases, the stress brings on different kinds of root rotting diseases and organisms,” said William McKinley, certified arborist. “And these organisms begin to attack and feed on the root tissue and eventually they reach a point where they’ve actually invaded what we call the root collar, or the base of the tree. So when trees lose enough of their woody structural roots that bear the tree’s load then they become susceptible to uprooting and falling over.”

Some trees are more at risk than others. For instance, white birch trees are threatened and dying in great numbers because they need more water than the average tree, said Larry Moss, landscape architect. Redwoods face a similar battle. Even with outdoor watering allowed now that the drought is over, it may not be enough if done incorrectly.

“Often, irrigation systems are designed to water very shallow and this doesn’t promote deep root growth, and that can be a susceptibility factor,” McKinley said. “You have incompatible landscapes, like turf grass and ground covers planted underneath the trees and these types of landscaping affect the trees’ overall health and vigor because they steal away important water and nutrients which normally would be dedicated to trees. So you get trees developing very shallow root systems and on top of that then you have these invading disease organisms infecting the root systems of the trees.”

Add in to this an external force, like the windstorm that blew through last week, and trees can be prone to fall and possibly cause property damage or injury to bystanders. This becomes a more important issue than just wanting an aesthetically pleasing place to hang a hammock, it becomes a safety issue.

To help fight the chance of a tree toppling on your property, there are good tree health guidelines to follow. Deeply watering trees can make a huge difference. Not just spraying the ground for 10-15 minutes, once a day, as most homeowners commonly do. McKinley said that longer watering times on fewer days is the key. Water for at least 30 minutes, once or twice a week, to get the water percolating down for deep root growth. Mulching is also important.

“Where you have ground cover particularly, and turf, wherever you can pull that back away from the trunk of the tree out toward the edge of the tree branches, what we called the drip line, that’s recommended,” McKinley said. Moss added that clearing away the ivy, which often likes to creep up the side of a tree, growing in the bark, is a good practice. A radius of three feet from the tree, or six feet wide total circle, will help the tree get the water and nutrients it needs. Cover the ground with wood chips or organic mulch to protect the roots and the exposed ground.

‘That simulates the kind of natural environment the trees are genetically programmed to live in, what they’re accustomed to, because basically they’re forest animals and we use them in artificial landscape settings that don’t really emulate natural forest like environments,” McKinley said.

  Charly Shelton, Mary Okeefe