Mario Bautista
Fall is typically the time of year when homeowners spend some time improving their lawns in order to get them ready for winter and next spring’s flush of green growth. Unfortunately, many of these tasks may need to be put on hold thanks to the drought which we are currently experiencing in Greater Columbus.
Normally, Greater Columbus receives nearly 13 inches of rain during the three-month period of June, July and August. This year, just over 5 inches of rain has fallen on most parts of the region, leaving the parched soil nearly 8 inches short of normal precipitation.
The fact that we experienced several days during this period when temperatures were above 90 degrees Fahrenheit means that whatever moisture was present in the soil was lost due to increased rates of evapotranspiration. These conditions have caused most turfgrass that has not been irrigated to turn brown and go dormant. This is the normal physiological response for cool-season grass species.
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Postpone seeding turfgrass
While many homeowners like to reseed turfgrass in the spring, the ideal time to reseed turfgrass in Ohio is in late summer and early fall, from Aug. 15 through Sept. 30. This is because soil moisture levels and air temperatures during the fall are typically more conducive to germination and root development of seedlings before the soil freezes than they are in late spring and summer.
Because of the current drought, we do not recommend seeding turfgrass right now, unless supplemental irrigation can be provided from now until late fall. There simply is not enough soil moisture present in Greater Columbus for turfgrass seed to germinate and develop root systems before the soil freezes.
An additional challenge is that because turfgrass plants in nonirrigated lawns are brown and dormant right now, it is difficult to know exactly where reseeding will be needed. Once soil moisture returns, many of these dormant grass plants will start to regrow and green-up, but some plants, or even entire lawns, may not survive if they were stressed in some way before soil moisture levels dried up.
Consider drought-tolerant species
Whenever soil moisture improves and you do reseed, whether that is later this month or early next spring, you may want to consider planting turfgrass species, which are more tolerant to drought and hot weather. While many lawns in Ohio consist primarily of Kentucky bluegrass, seeding a mixture of bluegrass and fescues will result in a turfgrass stand, which will be more resilient to drought and hot, dry conditions.
Varieties of both tall fescue and fine fescue are more drought tolerant than bluegrass varieties. Tall fescue varieties are more resilient than fine fescue varieties in high-traffic areas of the lawn.
You can review the performance of different turfgrass species and varieties online at buckeyeturf.osu.edu/turfgrass-establishment-series. This website also contains fact sheets, videos, blog posts and other resources related to all aspects of establishing and maintaining a high-quality lawn.
Park the fertilizer spreader
While we normally recommend applying needed fertilizer to lawns in the fall, such applications should not be made this fall unless soil moisture is replenished. In fact, most lawn-maintenance tasks such as dethatching, aeration and even mowing can damage dormant turf plants and should not occur until soil moisture is replenished.
If rainfall becomes more frequent in September and October, fertilizer applications and other lawn maintenance tasks can be completed in November.
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Weeds survive drought
Thanks to evolution and natural selection, many weeds seem to survive quite well during periods of drought and hot weather. While desirable turfgrass species are brown and dormant right now, some weed species, including crabgrass, are green and growing.
While it is too late to apply an herbicide to clean up crabgrass escapes, you should map areas of your lawn where crabgrass is present now and plan to treat those areas next spring and summer with a preemergent herbicide.
Winter annual weeds such as chickweed, henbit and bittercress will likely begin to germinate this month, even in dry soils. These weeds can be controlled with a preemergent herbicide in September if you have locations in the lawn where these weeds flourished last winter.
Another option is to wait and see where these winter annual weeds pop up and treat them in October or November with a post-emergent herbicide.
The good news is that you may have more time on your hands this fall to do fun things, like watching Buckeyes football.
Mike Hogan is Extension Educator, Agriculture and Natural Resources and associate professor with Ohio State University Extension.
hogan.1@osu.edu
