Summary of Suggested Lawn Maintenance
Home owners have varying levels of interest in turfgrass maintenance. The more intense one is regarding fertilization, irrigation and weed control, the nicer the lawn. However, there will be more work and expense—heavily fertilized lawns are greener and grow faster but need to be mowed more frequently.
Establishment or Overseeding:
All grasses are best seeded or otherwise established just prior to their optimum growth period. For warm season grasses (Bermuda, zoysia, buffalograss) this is in Late April, May and June before the summer growing period.
Tall fescue and Kentucky bluegrass, may be seeded in the spring and fall before growth begins. The best time to seed these grasses is in the fall. New fall growth will have fall, winter and spring to establish deep roots before the stress of summer. Seeding in spring will give good germination, but there is usually not enough time to develop an adequate root system before summer. Much of the spring planted fescue will die.
Seeding or Over-seeding Fescue
HLA-6419: Establishing a Lawn in Oklahoma
PSS-2583: Choosing, Establishing, and Managing Bermuda Grass Varieties in Oklahoma
HLA-6418: Selecting a Lawn Grass for Oklahoma
Tall fescue should be mowed 2.5 to 3 inches year round. The suggested mowing heights for Bermuda is 1.5 to 2.5 inches. Taller grass produces more energy for the plants, keeps the ground cooler in the summer and reduces the likelihood of weed invasion.
Fertilization is best done during the turf grasses growing season. Fertilize Bermuda with 2-5 lbs of Nitrogen per 1000 sq ft. in divided applications over the growing season (from full green-up in late April to the first of September. Zoysia needs about half the amount recommended for Bermuda.
Fescue is best fertilized once or twice in spring (March through May) and twice again in fall, once in September and again in November, with 1 lb of nitrogen per 1000 sq ft. each application. Most of the fertilizer should be in the fall. Fescue should never be fertilized in summer, it decreases heat tolerance and promotes disease.
Bermuda needs .5 to 1 inch of water per week and fescue must have 1 to 2 inches per week, depending on the season. While Bermuda has drought tolerance, fescue will not survive the summer without rainfall or irrigation. The reference below has good information about irrigation and water needs for turfgrasses.
HLA-6610: Simple Irrigation Audit for Home Lawns in Oklahoma
The best time for dethatching Bermuda is before growth begins in March and April. Fescue rarely needs dethatching unless it is preparation for reseeding in fall.
Preemergent: Apply a preemergent to prevent summer weeds such as crabgrass between mid February and mid March. To prevent winter weeds make an application in the fall—mid August through mid September. One of the commercial brands containing dithiopyr, pendimethalin or prodiamine are good choices.
Recommended Preemergents Availability (PDF)
Postemergent Broadleaf Control: One of the many brands containing a combination of herbicides such as Weed-B-Gon or Trimec are useful for established weeds. They work best on small rapidly growing weeds. The most effective time is spring and fall, especially in fall. Mature weeds and summer dormant weeds are less susceptible to these herbicides.
Non-selective Herbicide: Glyphosate, found in Roundup and many others will kill anything green. It may be used on dormant (brown) Bermuda lawns in January and February to kill any green weed. It should never be used on zoysia or tall fescue.