Summer 2019 delivered hot, dry weather with sporadic rainfall. With fall approaching, now is the time to adjust your turfgrass management program to promote a smooth transition into dormancy and green-up next spring.
The height of the warm-season turfgrass growing season spans from May to October. Given average conditions — regular rainfall and moderate temperatures — Bermuda grass, zoysia grass, St. Augustine grass, centipede grass and other warm-season species respond quickly to cultural and maintenance practices such as mowing, fertilizing, aerating, topdressing and weed management.
From mid- through late summer, rainfall across Georgia has been variable, with some areas receiving average rain and other areas experiencing drought. Moisture stress in turfgrasses can be recognized in the early stages by a dull, bluish-gray cast. Additionally, take note of footprints and tire tracks in the turf that do not rebound.
For areas with a lack of rain, applying irrigation can help spur grass growth.
Follow these tips from University of Georgia Cooperative Extension for managing turfgrass as it transitions into dormancy:
- Raise the cutting height within the recommended mowing range
- Do not apply nitrogen-containing fertilizers
- Modify herbicide programs during high temperatures and moisture stress
- Water deeply and infrequently
- Mulch clippings versus bagging them, or “grasscycle”
- Use water-conserving and drought-tolerant turfgrasses
Raise cutting height
Turfgrass stress can be reduced by using a sharp mower blade and raising the cutting height by a half inch or to the tallest allowable height of the recommended mowing range during drought. A clean cut reduces moisture loss through wounds and minimizes entry points for disease. Taller shoots promote deeper roots and a dense canopy can help to reduce ground surface temperatures and conserve moisture. Grasscycling can also help to conserve moisture.
Avoid nitrogen applications
As grasses move into dormancy they need to “harden off.” Nitrogen fertilization encourages new shoot growth, which directs plant sugars and other metabolites away from storage organs (e.g., rhizomes, stolons and crown). These storage organs and sugars provide energy for the grass to green-up the next spring. By allowing the plant to harden off and accumulate sugars in the storage structures, the grass is better able to survive winter stresses and recover next year.
Modify herbicide programs
Many herbicides act upon plant growth processes and can be less effective during periods of drought when weeds are not actively growing. In addition, certain herbicides may cause damage to drought-stressed turf or nontarget landscape plants due to volatilization and drift during high temperatures. Review pesticide labels for specific information regarding temperature requirements, watering requirements, and proper application.
Water deeply and infrequently
The optimum watering schedule can be roughly determined by observing the number of days that pass between signs of moisture stress. Apply sufficient water to saturate the root zone to a depth of 6 to 8 inches.
Clay soils and sloped areas may require staggered watering intervals to allow time for water infiltration between cycles and to prevent runoff. Irrigating in the early morning conserves water by reducing evaporation and drift. A good practice is to align watering schedules with drought-management rules so, in the event of a declared drought, the appropriate watering program is already in place. The 2010 Water Stewardship Act permits lawn watering between the hours of 4 p.m. and 10 a.m.
Use water-conserving and drought-tolerant turfgrass cultivars
The UGA Turfgrass Breeding Program continues to make excellent strides in developing improved cultivars with low water use and high drought tolerance. For new installations, or where turfgrass replacement is needed, look for improved cultivars such as ‘TifTuf’ Bermuda grass. Visit www.GeorgiaTurf.com for more information on selecting turfgrasses.
