Windstorms make local trees a danger

Last January, the Sisters Country was hit by one of our periodic windstorms. Shingles were torn off homes by the strong winds that roared through here, and in some cases trees went crashing down on homes and property.

If you don't want to see that happen to your trees, you may want to check on their health.

Firs, ponderosa pine, aspen and old cottonwoods have adapted pretty well to the wind. But some are wind-thrown, the tops broken out, trunks cracked and split and uprooted.

One of the most insidious problems ornamental firs can suffer from in this area is Schweitzii root rot. This slow tree-killer infects mostly Douglas fir, but can also get to other conifers in your yard.

There are visible signs of a problem.

Darin Stringer is a private forester who enjoys working with a variety of clients throughout the Northwest, among them Deschutes Land Trust. He says that having "cow-pie" conks under any of your trees is bad news; the tree is dying (see photo at right).

When fresh, the conks are yellow-green, with a velvety cap, then known as the velvet-topped fungus. The fungus ages rapidly to a yellow-brown and at maturity has that "cow-pie" look.

There is no cure for a tree that is dying from root rot. It is best removed before it topples over on your property.

Sometimes a property-owner can cause problems by providing too much TLC. Over-irrigating trees can induce root rot, cause an unbalance in the soils affecting a tree's growth, eventually encouraging a variety of fungi to alter the health of the tree and its growing process.

Most conifers in the Sisters Country are adapted to dry growing conditions in summer; soaking them with irrigation water could do more harm than good.

An over-irrigated tree could also develop serious physical problems without showing symptoms the average person would recognize. If you should look up at that towering Doug fir in your backyard and notice the top thinning or dying back a little; not much growth on the ends of the limbs in summer, or a few red needles in summer, it's probably a good idea to have a professional forester come out and take a look at your old friend.

Stephan Fitzgerald, silviculture, wildlands fire and educational specialist for the OSU Extension Service based in Redmond, spends a great deal of time inspecting trees throughout Central Oregon.

"I see Western gall rust as a serious problem for ponderosa and lodgepole pine," he says. "It's a disease that weakens the main stem of the tree and could cause it to fall in a high wind." He also points out that,"homes located in forested areas adjacent to Sisters may be in jeopardy - especially those with big trees on the southwest side of a home - our big storms often come from that direction."

Both Fitzgerald and Stringer point out that limbing and topping can also affect the stability of a tree. Firs and pines are shaped by nature to handle wind, lopping off the top to enhance a view of the mountains could induce decay and rot, as well as deform the tree in such a way that it is less flexible in wind and can suffer catastrophic breakage.

Our glamorous old black cottonwoods are usually short-lived (20 to 30 years), although sometimes they reach 400 years of age. These silver-leafed beauties are favorite wind-breaks and shade trees in the backyard. The scent of a cottonwood in spring is delightful, and the wispy "cotton" that fills the air is a sure sign that the nights will be warmer.

Often, however, these big poplars may have been damaged in their early years and hidden rot got going, a problem one cannot see until the limb breaks or the tree topples over. Older limbs on cottonwoods can rot inside, causing them to weaken. In a windstorm they can break and fall on the roof of your home or car.

Native and exotic birch trees are becoming more popular for landscaping, and in many areas have reached a size where they could cause damage to a structure should they blow over. There are many different species of birch trees that vary in bark color, growth and resistance to pests and diseases, and they use water like our native quaking aspen.

There is a sad piece of news facing those who have imported local and exotic birch trees onto their property: the bronze birch borer, agilus anxius, is infesting ornamental birch in the Willamette Valley. The infestation may weaken or kill them, leaving a risk of them blowing over.

The insects that are infesting the birch could - and most likely eventually will - strike the birch trees planted in Sisters. You can ask someone like the extension service forester or private tree consultants to keep an eye on your costly birch landscaping to help you keep them healthy - and off the roof of your home.

Providing a little common sense, TLC and health checks for the trees about your property will provide you with an opportunity to relax when the next windstorm comes roaring through the countryside.