I have several favorite shade trees, but first I want to discuss what type of trees I would not plant in my yard.

Weeping willow: One "strike" against this tree (Salix babylonica) is its size. It's way too big for the average home lot, growing 50 to 70 feet tall and wide. Another strike is its predisposition to limb breakage. A huge strike is the willow's invasive root system. It will encroach on gardens, making it hard to grow other plants, and the roots will easily clog sewer pipes, septic systems and water channels. Yet another strike is its susceptibility to aphid infestations and die-back cankers, making it a short-lived tree. A final strike is that many people are allergic to its pollen. This tree definitely should not be planted in the regular home landscape.

If you must have a weeping willow, consider a smaller type of weeping willow. Salix caprea pendula "Kilmarnock" is a weeping pussy willow. It's a small umbrella-shaped tree. Another is Salix purpurea "Pendula," a weeping purple willow that grows into a small weeping tree when trained to a standard trunk.

Poplar: Hybrid poplars (Populus spp.) should not be planted as a backyard shade tree. Purveyors of hybrid poplars tout their fast growth and ability to provide quick shade. They do grow rapidly, but have many of the weeping willow's undesirable qualities, including weak wood, invasive roots and a short life span. They also have a propensity for developing suckers from their roots.

The "hybrid" tag is not synonymous with insect or pest resistance as sometimes implied. In many cases, hybrid poplars have simply been bred for fast growth. Their roots grow rapidly, too, and the trees don't live much longer than 15 years.

Pin oak: This (Quercus palustris) is not necessarily a "bad" tree with many strikes against it -- just one big one. Pin oak is one of the fastest growing oaks and once established and growing well, it's very tolerant of flooding and urban soil conditions. However, it doesn't grow well in our region's alkaline garden soils.

Pin oak develops a problem called "pin oak chlorosis" in alkaline soils. Efforts to change the soil by adding sulfur or iron are usually unsuccessful and are not a long-term solution. They should not be planted in our region.

Red oak grows well in this area and is a good alternative to pin oak. It has a rounded crown when mature, grows relatively fast for oaks and has a rich red fall color.

Other shade trees that I would not recommend planting are weeping birch (Betula pendula) because it's subject to attack and death from bronze birch borer; silver maple (Acer saccarhinum) because it's way too big, weak wooded, has invasive roots and is prone to wood rot; and ash (Fraxinus americana and Fraxinus pennsylvanica cultivars), which are nice trees but subject to attack from ash borer and verticillium wilt.

Which shade trees would I plant in my yard?

My favorites are "October Glory" and "Red Sunset" red maple, "Heritage" river birch and red oak.

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