Richard Bogren, Gill, Daniel J.
For Release On Or After 02/26/10
By Dan Gill
Although our lawns are still dormant this month, you can begin now to plan your strategy to have an attractive, healthy lawn this summer. Since the grass is still dormant, most lawns look relatively bad, so don’t judge yours too harshly at this point.
You should go ahead and identify areas where grass has died out completely and only bare soil remains. These areas will have to be repaired in April or May. Otherwise, wait until late April or May to evaluate your lawn and make final decisions on any repair work that will need to be done.
Several common causes of lawn thinning include insect and disease problems, heavy traffic, poor soil fertility and too much shade. Poor maintenance, such as improper mowing and watering, also can be factors. One or more of these problems may be affecting your lawn, and the situation may stretch back well into the past.
Winter weather does not stop the lush growth of winter weeds in lawns. Most cool-season weeds will not cause significant damage to a healthy lawn, so control is generally not critical (control is more important for cool-season perennial weeds, such as dollar weed and clover). I would, however, recommend that you mow your lawn now and occasionally hereafter to keep cool-season weeds growing in the lawn from flowering and setting seed. This will reduce annual, cool-season weed problems next year.
You may apply a lawn weed killer now if you choose. A number of commercial lawn weed killers available control a wide variety of weeds. Make sure you choose one that is labeled safe to use on the type of grass you have. You should know what kind of weeds are growing in your lawn – you might take some to the nursery with you for identification – so you can check the herbicide label to make sure the product will control them. Follow label directions carefully to avoid damaging the turf or landscape plants. Two applications generally provide the best control.
Whatever weed killer you choose, do not use a weed-and-feed. It’s too early now to fertilize your lawn, and it will still be too early in March when lawns begin to green up. Research shows that turf grass does better if you wait until early to mid-April to make the first application of fertilizer to your lawn. If you have a weed problem that you need to deal with now, use a weed killer without fertilizer.
One of the more common lawn diseases is brown patch, particularly for St. Augustine grass. This disease is caused by a fungus that thrives in cool, moist weather and causes areas of brown grass that can grow quite large. Most damage occurs in the fall, and there is no need to treat dormant grass now.
This disease can kill the grass, but it is more common for it to weaken the turf – causing the affected areas to green up poorly in the spring – and make the lawn more susceptible to weed encroachment. Should rainy weather this spring encourage new outbreaks (noticeable after the lawn greens up as new, rapidly expanding brown areas), active brown patch can be treated with a lawn fungicide such as Immunox and others.
Chinch bugs are not active now, but they may have damaged your lawn last summer. These bugs are primarily a problem June through early October, and if areas of your lawn died during that time, the likely cause was chinch bugs. Unfortunately, these insects often kill the grass outright, and you will most likely need to replace the turf if it hasn’t greened up by May.
Lawn areas that have been damaged by wear and tear from dogs, children or foot traffic can be helped with extra care. In early April, use a garden fork to loosen the compacted soil in bare areas, fertilize the lawn – including the damaged areas – and water the lawn regularly to encourage growth. Keep traffic in the area to a minimum until the turf has filled in. If the area is large, you may want to loosen the soil and lay new sod for faster coverage. Keep in mind that if heavy traffic continues, the grass will be damaged again.
One of the leading causes of decline in turf quality is shade. As trees age, they grow larger and create more shade in the landscape. Often, areas where grass once grew well become too shady for grass to thrive. Ultimately, landscaping the shady area with shade-loving shrubs, herbaceous perennials and ground covers will provide the best long-term solution.
Finally, this is not a good time to fill in lawn areas because the grass is not in active growth and will remain covered by the fill for many weeks. Wait to fill lawn areas until May through September. Grass will only grow reliably through one to two inches of fill. If you need to fill deeper, you may have to replace the turf in those areas. Don’t forget that trees also can be injured or killed by excessive fill deeper than 2 inches covering large areas of their root systems.Rick Bogren