Lauderdale: Lawn care now

As summer gets ready to move into fall, there are some important lawn-care tasks to continue and new ones to be done.

We should continue to mow at the proper height depending on grass type. Mow centipede to 1 to 2 inches. Most people mow to 2 inches since home lawns are often too uneven to mow lower without scalping the grass. Since the rule of thumb in mowing grass is to only remove one third of the grass blades, mow when the grass gets 1 inches (for 1 inch mowing) to 3 inches tall (for 2 inch mowing). Make sure to raise the mowing height to 2 inches several weeks before expected frost to prevent winter injury.

The best mowing height for Bermuda is 1 to 2 inches. Mow the grass before it gets 1 to 3 inches tall. You should always grasscycle by leaving the grass clippings on the lawn. This technique will provide up to 25 percent of the lawns fertilizer needs. Mow St. Augustine to 3 to 4 inches, zoysia to 1 to 2 inches depending on variety and tall fescue to 3 to 4 inches.

Fertilization is important to have a healthy lawn, but be careful not to overdo it. Between now and 4 to 6 weeks before expected killing frost (mid-September) fertilize warm-season grasses with 1 pound of potassium per 1,000 square feet. One pound of potassium can be applied by using 1 pounds of muriate of potash (0-0-60), 2 pounds of potassium sulfate (0-0-50), or 4 pounds of sul-po-mag (0-0-22) per 1,000 square feet. This potassium application will help prevent damage to warm-season grasses from the stresses of winter and get them off to a good start next spring. This is the way to winterize your warm-season lawn. Do not fertilize any warm season lawn with a high rate of nitrogen containing fertilizer after August.

Fertilizing at the wrong time and with excess nitrogen is one of the reasons we have so many problems with centipede. If you have already fertilized centipede with a fertilizer containing nitrogen there is no need to do it again. Do not apply nitrogen containing fertilizers to centipede after August. Bermuda can be fertilized in August at the rate of 8 pounds of 12-4-8 or 6 pounds of 16-4-8 per 1,000 square feet. Use half that amount on St. Augustine or zoysia in August. To give Bermuda one final push for good fall growth it can be fertilized at half the August rate in September. Bermuda grass is the only warm-season lawn I would recommend any nitrogen on in September.

Watering hasnt been needed much this year. About 1 inch of water should be applied when irrigating. The best irrigation timing is the early morning when the grass begins to turn a bluish gray color indicating drought stress. This method conserves the most water.

Insects are a concern in lawns but rarely a problem. If you have Bermuda grass, be on the lookout for fall armyworms now. They are rarely found in high-maintenance lawns, but where they are found they can do serious damage quickly. Look for discolored areas, large numbers of birds feeding in lawn areas and more closely in the lawn for fecal pellets. These insects are not true worms but caterpillars that can be green, brown or black with a Y-shaped marking on their head.

Treatment for fall armyworms is only needed if you find an average of 1 per square foot of lawn area. If detected at these levels, lawn insect-control products labeled for home lawns include those with pyrethroids (active ingredients ending in thrin like bifenthrin) or trichlorfon (trade name Dylox and often found in 24 Hour Grub Control Products) can be used following label instructions. Please always follow label instructions for safe handling and application of all pesticides. Do not apply to lawn areas where bees are actively foraging on weed flowers.

Weeds are always a hot topic. No matter what weeds you have, now is not the best time for post-emergence control. Summer annual weeds (like common lespedeza or crabgrass) are more easily controlled from April to June. Perennial weeds are easier to control from October to November and April to May. Winter annual weeds can be controlled from November to March.

For prevention of annual bluegrass and winter broad-leaf weeds, a late August to September application of pre-emergence herbicides containing benefin, trifluralin, dithiopyr or pendimethalin can be used. Do not apply a pre-emergence herbicide if you plan on over-seeding in the fall. These products are often sold as crabgrass preventers but are labeled for late summer and fall application for prevention of winter weeds.

Continue reading here:
Lauderdale: Lawn care now