Turf grasses are divided into two categories based on the temperatures they prefer. Cool-season grasses grow best in the spring and fall, with optimum growth when the temperature is between 60 and 75 degrees F. Warm-season grasses grow best in the summer, with optimum growth at 80 to 90 degrees F. Delaware is in the transition zone. Our winters are too cold for warm-season grasses and our summers are too hot for cool-season grasses. Since we are in the northern part of the transition zone, we grow primarily cool season grasses but they may go dormant in hot, dry summers.
Tall Fescue – The turf-type tall fescues are excellent for Delaware. While they take a little while to establish or recuperate, since they are a clump-type grass, they are extremely wear-resistant, drought-, heat- and salt-tolerant, and moderately shade-tolerant. Tall fescues have few disease problems and require less maintenance than other grasses. Kentucky bluegrass is the first grass to brown out in the summer and tall fescue is the last. Especially for a new lawn in Delaware, tall fescue is the best choice.
Other cool-season grasses include: Kentucky Bluegrass, Perennial Ryegrass, Fine-leaf Fescues, Bentgrass
Zoysiagrass – This is the only warm-season grass grown as a lawn in Delaware. Zoysia is easy to identify because its leaves are covered with stiff hairs. It remains brown well into the spring and turns brown again with the first fall frost. Zoysia is very aggressive and is often a bone of contention between neighbors. The best place for zoysiagrass is at a beach residence where it is viewed only during the summer. Zoysia does require less mowing and some people are happy with a lawn that is only green for 4-5 months out of the year.
Since no one grass has a full list of desirable characteristics, we use blends of grasses to achieve versatile lawns with fewer shortcomings. Tall fescue and zoysiagrass are usually not mixed with other grasses.