Growing Healthy Turf in the Transition Zone

When I first began learning about turfgrass management in preparation to assist with the Turf Love program, I heard a lot about Virginia being in the Transition Zone, where “you can grow warm season and cool season turf, but you can’t grow either well” as my late mentor Bob Winters would say. The Transition Zone, shown in the map below, is a climatic region with generally hot summers and cold winters, both of which can stress warm and cool season species. 

Map of the United States showing preferred growth zones for cool and warm season species and the transition zone. 

To understand how and why both types of turf can struggle in this region, it’s important to know the basics of cool and warm season growth cycles. The ideal growing season for warm season grasses, including bermudagrass and zoysiagrass, is late spring through summer, when temperatures average 75–90 degrees. With our warming climate, this heat tolerance is an important strength to keep in mind when selecting a turf species for your property. Warm season grasses are also significantly more drought tolerant than cool season species and generally are less susceptible to pests and disease. Warm season species also tend to grow and spread more rapidly, which can be helpful to prevent bare spots in the lawn, but can also lead to encroachment into landscape beds and requires more frequent mowing in the peak of their growing season. Another important feature of warm season grasses is that they go dormant in the winter, which causes them to turn a yellowish-brown color for about four months out of the year. 

Typical growth chart for warm season turf species. 

The ideal growing seasons for cool season species, including tall fescue, bluegrass, and ryegrass, are spring and fall. While we see significant shoot growth in the spring, most cool season root growth occurs in the fall, which is the ideal time for any necessary fertilization. Cool season species are still most commonly grown in this region; however, they are not as well suited to deal with increasing average temperatures. Cool season species generally require more water for healthy growth, and most require annual overseeding to help fill in bare spots. Cool season grasses maintain their green color throughout the year, unless there is an extreme drought in the summer, and require less mowing in the heat of the summer when growth slows due to heat stress. Cool season species are also more shade tolerant than warm season turf, which cannot grow in shade. 

Typical growth chart for cool season turf species. 

While there are positives and negatives for both types of turf in this region, it’s important to understand the habitat requirements and growth patterns for both to make sure that you have the best chance of success with growing the lawn you want. Once you’ve decided on what type of turf you’re going to grow, it’s equally important to follow the appropriate management schedule for that species. Over fertilization and fertilization at the wrong time of the year can cause significant environmental harm, and often results in wasted time and money. If you’re unsure which turf type is best for your property, or if you’d like help managing your lawn, consider signing up for the District’s Turf Love program, which includes a professionally analyzed soil sample and written report detailing recommendations to support your lawn care goals. 

Read more articles in the Winter 2026 CSWCD Newsletter.