KENNEWICK -- I'm often asked about the best trees to plant in our area, but usually not about the worst trees to plant.

My reasons for deeming a tree "the worst" is its extremely large mature size, susceptibility to disease or insect pests that are difficult to impossible to control, invasive roots and weak wood prone to breakage from wind and ice.

So what trees do I advise against planting on the normal home lot? Here goes ...

Silver maple (Acer saccharinum)

Silver maple is a common older tree in our area, planted in years past because of its fast growth. However, with fast growth comes weak wood and invasive roots. Silver maple is also a very large tree when it reaches maturity, much too big for today's average home landscape. Plus, as silver maple ages, surface roots become a significant problem, lifting sidewalks and making lawn mowing difficult.

Ash (Fraxinus americana and Fraxinus pennsylvanica cultivars)

Ash trees are well suited to our soils and perform quite well until they are attacked by the ash borer which has become prevalent in our region. There is no practical control for ash borer, so the longevity of an ash tree in a home landscape is questionable.

Quaking aspen (Populus tremuloides)

Who doesn't like the trembling leaves and the spectacular golden fall color of aspens? Many folks love this tree until it's been growing in their landscape for a couple of years. That's when the aspen roots start sending up suckers, lots of suckers. According to research, aspen roots are start suckering when they are about two years old and a quarter-inch in diameter, plus aspens develop extensive root systems. This explains how native aspen stands grow larger and regenerate themselves after forest fires. In home landscapes this ability becomes a nightmare.

Hybrid poplars (Populus sp.)

Hybrid poplars are created by breeding two or more poplar species together. Because poplars are some of the fastest-growing trees in northern temperate zones, plant breeders have worked at creating hybrid poplars that are very fast growing for pulp, energy, and lumber production. However, the title "hybrid" doesn't equate to a good landscape shade tree. Poplars and hybrid poplars tend to be short-lived (15 years or less) because they are prone to trunk canker diseases. They also have shallow, invasive roots and weak wood. Depending on the hybrid they may also produce cottony seed masses and root suckers.

Willows (Salix sp.)

There are a variety of large, fast-growing willows planted as shade trees in home landscapes. This includes weeping willow (Salix spp.); the Austree willow, a cross between Hankow willow and white willow; and corkscrew willow. These are nasty trees with very aggressive roots that spread out as far as the tree is tall and farther. These roots proliferate where water is available and can damage irrigation lines, sewer lines and septic system drain fields. Willows also have weak wood, shallow roots and are prone to canker disease. All of this contributes to making them relatively short lived shade trees (30 years).

While some trees are not well suited to the normal home landscape, most trees have some redeeming value. Willows will tolerate fairly wet soil, where many other trees won't. Poplars and willows with invasive roots can be used to stabilize soil on river and stream banks.

Fast-growing trees can serve as temporary windbreaks until slower growing species have a chance to grow. However, the trees on my "worst list" should usually be avoided. There are many other better choices for planting in your landscape.

* Marianne C. Ophardt is a horticulturist for the Washington State University Benton County Extension.