David M. Kopec, Extension Turfgrass Specialist
Many homeowners and small business owners try to maintain bermudagrass in moderate shade conditions only to end up with a poor lawn. This is because bermudagrass is actually a full sun grass. The result often ends up with spindly, thin turf which is scalped at normal mowing heights and mowing frequencies. Other warm season grasses like zoysiagrass grow too slow, or like St. Augustinegrass, will not take very low winter temperatures. Neither of these grasses like to be overseeded for the winter, as well.
A viable alternative for heavily shaded areas is tall fescue (Festuca arundinacea). This is a cool season grass which will stay green all year round provided it is grown on a deep soil, mowed and fertilized properly, and watered properly year round. Its greatest water use will be in the summer months.
Applicable uses for tall fescue in small landscape settings include:
1. small patio areas in business settings
2. small lawns in home backyards
3. heavily shaded areas in townhouses/apartments
4. shaded access areas like hotel entrances, restaurants, small professional buildings, etc.
Preferably, the area should be 1000 ft2 or less (to save water). In full sun, tall fescue will use about 30% more water than bermudagrass in the summer and about the same as 'full sun bermuda' does when fescue is grown in the shade during the summer.
Tall fescue is grown as an "all or none grass," in that it is not compatible with bermudagrass. If you have a shaded area with bermudagrass, or a small bermuda area you are changing over to tall fescue, here is the plan to follow.
Eradicate the bermudagrass:
1. Mow the bermuda high and regularly at 2.0 inches.
2. Fertilize it with 1.0 lb. of nitrogen per 1000 ft2.
3. Water the lawn like you want to keep it (avoid drought stress).
4. Spray the lawn at 10:00 am with Round-up or Doomsday. Let the product dry on the leaf. Turn the irrigation off for that night only.
5. Turn on the irrigation the next day and water as normal. Do not shut off the water.
6. In 5-10 days, (keep watering) 95% of the bermudagrass will turn brown.
7. Apply another 1/4 lb. of nitrogen per 1000 ft2.
8. Re-spray the areas which are still green with Round-up (repeat steps 4 and 5).
9. After another 6-8 days, all bermudagrass should be killed.
10. Shut off the water and let the entire lawn remain brown.
Steps 1-10 should be started about five to six weeks before overseeding with fescue.
Establishing the fescue lawn:
It is not necessary to roto-till the dead bermudagrass up. In fact, you will make a mess. Better yet, let it work for you as a stubble mulch.
1. When the old dead bermudagrass is bone dry, verticut (ren-o-thin)
the lawn in three or four directions, going about one inch deep. This opens
up the seed bed.
2. Apply the fescue seed at the rate of 8 lbs. of seed for every 1000 ft2. Don't over do it. You will end up with a weak and spindly lawn. Apply the seed in multiple directions with a drop spreader. It is important to spread the seed evenly, since tall fescue grows like ryegrass (bunchgrass habit).
3. Rake the seed in the stubble mulch you made. You may topdress it with composted steer manure for better results. Roll it afterwards.
4. Water the lawn three times daily for five minutes at 10:00 am, 12:00 noon, and 2:30 pm.
5. When the turf is 2.5 inches tall, mow it with a rotary mower to 2.0 inches.
6. Follow with a fertilizer application of 16-20-0. Apply 5 lbs. of product per 1000 ft2. Water it in.
7. Water every other day or longer and mow every time the lawn reaches 2.5 inches in the fall and winter.
8. Next spring (April), raise the mowing height to 3.0 inches and leave it there. Mow back to 3.0 inches every time the lawn reaches 4.0 inches.
9. Fertilize the lawn with ½ lb. of nitrogen per 1000 ft2 in February, March and April. Do not apply nitrogen fertilizer in Phoenix or Tucson after May 1. Instead, apply iron containing products for green summer color.
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director, Cooperative Extension, College of Agriculture & Life Sciences, The University of Arizona. The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.