By DR. DIANE RELF

By DR. DIANE RELF

Extension Consumer Horticulturist

Many home lawns have heavily shaded areas where it is early to establish or maintain quality turfgrass. The competition for light, nutrients and water creates stresses that weaken turfgrass plants and reduce their growth potential. The fact that shade attracts people during the hotter periods of the year adds to the problem by increasing soil compaction in the area.

Trees that develop a shallow, fibrous root system, such as sugar maple, are ektremely competitive with turfgrass for moisture. In addition, research has demonstrated that certain trees, such as the silver maple, excrete toxic substances that have a negative influence on Kentucky bluegrass growth.

Shade from the Tree Causes

Variety of Problems

Trees with heavy shading potential in the form of many large leaves and thick branches, such as some oaks, maples, and sweetgums, create a poor environment for turfgrass. Trees, such as honey locust, that have more of an open canopy, allow more light to reach to the grass.

The shade canopy tends to moderate temperature fluctuations by lowering daytime temperature and keeping it warmer at night by preventing release of the heat. This moderating effect on temperature helps humidity remain high both day and night. This relatively constant temperature in the presence of high humidity and subdued light creates conditions conducive to fungal activity.

The turfgrass growing in this environment produces succulent, thin cell walls and elongated leaves that are heat, drought and disease susceptible. In addition, the reduced sunlight leads to decreased food production and a plant that is less able to recuperate from foot traffic, mower damage, or plant pests.

Since shade is a poor environment for turfgrass, it is essential to develop a good management program in shady places.

First, select shade tolerant grasses. The fine-leaf fescues are consid