Drought affects all turf areas differently
We are fielding a number of calls like “Why is my lawn is turning brown while my neighbors isn’t, even though neither of us irrigate?”. On any given turf area or in a neighborhood, we can see a wide variety of responses to the current drought. Following is a list of factors that will affect how fast a turf shows droughty symptoms or dormancy:
Species: Tall fescue is one of the last to show drought symptoms, many days to weeks following bluegrass or perennial ryegrass. Since dormancy is a survival mechanism, Kentucky bluegrass and perennial ryegrass tend to survive drought better. (Actually Dr. Yiwei Jiang here at Purdue is trying to understand why cultivars respond differently to drought);
Mowing height: Higher the mowing height, deeper the roots and the better the ability to find water lower in the soil, but the higher mowing height has to be established in the spring;
Compaction/heavy soils: Compacted soils force shallow rooting;
Sodded lawns tend to show drought faster than seeded lawns because sod tends to have less root density than seeded lawns of the same cultivar and species, primarily due to soil texture differences between sod field and lawn;
High fertility or heavily irrigated will show drought symptoms faster;
Spring fertilizer vs heavy fall fertilizer: Better rooting with heavy fall fertilizer;
Shade from an abiotic source like a building tends to keep area cooler and turf will retain color longer;
Shade from a biotic source like a tree will compete with turf for the water and turf always loses;
Heavy traffic areas tend to show dormancy faster;
Thick thatch leads to shallow rooting in the thatch and very rapid drought symptoms;
Insect (grub) feeding or patch diseases also enhance dormancy symptoms.
Send corrections, suggestions, and comments to biehlj@purdue.edu