With this stretch of hot days and spotty rainfalls around the County many homeowners are all asking the same question, “Is my lawn really dead?” Check it out, in some cases, the upper portions of the turf may be dead but the crowns may still be viable. Pull up a few plants and tease apart the crowns at the base. Healthy but dormant tissue will be white and succulent; new green growth may be present. Dead crowns will be brown, straw-like throughout.
Dormancy in the Lawn – Turfgrass plants need soil moisture to sustain normal growth and development. The water use rates of cool season turfgrasses during the summer period will often exceed the rate which natural rainfall returns water back into the soil. Once the soil moisture reserves are nearly depleted, the turfgrass will begin to wilt. This condition is evident as the turfgrass turns from green to either bluish-green or gray-green. Wilt is a sign of water stress and is usually most evident during mid to late afternoon periods. A period of continual water stress that limits or prevents the growth of plants is termed drought. Once drought conditions develop, the lawn will stop all growth and development and proceed into dormancy.
Dormancy is characterized by the development of brown turfgrass. The turfgrass is not dead but instead in a condition to preserve the vital parts of the plant. By becoming dormant, turfgrasses reduce water usage and can concentrate the limited amount of available moisture into the crown, rhizomes and roots. This dormant condition will allow the turfgrass plant to survive adverse conditions for extended periods until soil moisture reserves are replenished. The length of time lawn grasses can survive in a dormant condition is contingent on a number of factors including soil moisture levels, daytime temperatures, condition of the turfgrass at the onset of dormancy, etc. In general, turfgrasses can be expected to survive in a dormant condition for up to 4 to 5 weeks with limited damage if temperatures are at or below normal. If daytime temperatures are elevated (mid-80’s or higher) consistently through the stress period, only 3 to 4 weeks of survival should be anticipated. Dormant grass is lost once the crowns, rhizomes and roots begin to dehydrate.