By Blake Jackson
Wisconsin’s hot and dry summer weather has placed significant stress on plants, and grasses are showing the effects in different ways. According to Bruce Spangenberg, a horticulture outreach specialist with the UW-Madison Division of Extension, some grasses have turned brown and appear dormant, while others remain green and continue growing. These differences reflect how individual grass species respond to heat and drought.
Grasses naturally differ in height, growth pattern, leaf color, thickness, and the way they produce flowers and seedheads. Another important distinction occurs internally: grasses are classified as either cool-season or warm-season plants based on the temperatures at which they photosynthesize most efficiently.
Cool-season grasses perform best during the cooler conditions of spring and fall. When summer temperatures remain in the 80s and 90s, their growth and food production slow considerably, and some may become dormant. Most Wisconsin lawns contain cool-season varieties, including Kentucky bluegrass, perennial ryegrass, and fine fescues.
It is also common to see different shades of green within the same lawn. Variations may result from different cultivars or differences in growing conditions. Grass growing in shaded areas, for example, may remain greener than grass exposed to full sunlight.
Warm-season grasses, by contrast, thrive when temperatures reach the 80s and can photosynthesize efficiently during hot weather.
Zoysiagrass is the primary warm-season lawn grass found in Wisconsin, but it is not widely planted because it remains dormant through much of spring and fall.
Wisconsin also has many native warm-season ornamental grasses, including little bluestem, big bluestem, switchgrass, Indiangrass, prairie dropseed, and side-oats grama. Their preference for warm growing conditions does not mean they lack winter hardiness.
Growing-season preference and the ability to withstand cold temperatures are different characteristics.
Some warm-season annual grasses are considered weeds. Crabgrass, foxtails, barnyardgrass, and goosegrass thrive during summer, often competing with cool-season lawns and garden plants. Fortunately, because they are annuals, these unwanted grasses typically die when cooler fall weather arrives.
Photo Credit: pexels-enginakyurt
Categories: Wisconsin, General