April 15, 2010
by Charlie Neumeyer
Victoria County Master Gardener

edited by Charla Borchers Leon,
Victoria County Master Gardener
Editor's note: Last week's column looked at some of the problems in our lawns that were caused by drought, flood, bugs and fungi. This week's Part II focuses on how to repair, or in extreme cases, replace our lawns
A typical St. Augustine yard with dead runners and roots because of either drought, insect or fungus damage, is bad enough that it will have to at least be re-plugged in dead sections, if not re-sodded completely. Weak grass stands are an invitation to weedy yards. each night.
This yard is infested with annual bluegrass taking over a weak St. Augustine grass that was lost last year, probably because of drought. It is extremely invasive with no good control once it is established, except to destroy it by pulling, tilling or spraying with glyphosate (Roundup, which will kill all grasses) and then replanting.
Chickweed, curly dock and Carolina geranium have infested this weakened St. Augustine yard. As with thistle and clover, these broadleaf plants can be controlled by either pulling, chopping or spraying with a broadleaf herbicide approved for your grass species.
No matter the method, all dead grass should be added to the compost bin.
If you have determined that you indeed have a dead lawn, not just one that is still dormant, now is the time to begin the repair process. The first step is to remove all of the dead plant material. You can accomplish this in a couple of ways.

Use your own mower - The least expensive method will be to use your own lawn mower.

Although, normally, Texas AgriLife Extension Service does not recommend removal of clippings from the lawn, this year may be the exception. If you have a very thick, dead turf, you will want to use the bagger on your lawn mower.

Lower your lawn mower a notch or two and make a pass over the dead area. If you are not using the grass catcher bag on your lawn mower, rake up the clippings.

Lower the mower another notch or two and make another pass, again bagging or raking the clippings.

Keep mowing lower until you have removed all of the dead turf closely down to the soil level. Do not try to remove too much at once. You will just clog up the mower.

Rent equipment - Another option is to rent a de-thatcher from a lawn and garden center. Using a de-thatcher probably will require less time on your part, but you will still have to rake up all of the dead plant material.

A third option is to rent a sod cutter. This machine uses a blade to cut strips of the sod that can then be rolled up and removed. The blade depth can be adjusted so that only the plant material, not the soil, will be removed.

No matter the method, all of the dead grass should be added to your compost bin. If you do not currently have one, now is a good time to start.

Or check with your neighbors to see if anyone needs some clippings for their compost pile.

Re-sod, Plug or Re-seed?

Now that you have a clean canvas, you need to decide how you want to proceed. There are three common ways to re-plant lawns: putting down sod, putting down plugs, or seeding a new lawn.

The most expensive will be re-sodding the entire lawn. The positive aspects of installing new sod over the entire lawn are obvious. You have a completely covered, green lawn and the feeling of instant satisfaction.

You can also be assured that you will have thick, new turf by the end of this growing season.

A second option is to take the pieces of sod and checkerboard them across the lawn. It does cut down on the expense because you are planting about half the amount of turf, but controlling weeds in the areas with no sod can be a problem.

A third option is to take the pieces of sod and cut them up. Using a machete, straight hoe or a hatchet, chop the sod rectangles in to 4- to 6-inch squares and plant them in a checkerboard pattern. This also will decrease the amount of turf needed, but again, weeds may become a problem.

With any of these methods, the application of a pre-emergent herbicide will be helpful.

A broadleaf herbicide approved for your grass variety will be useful for any weeds that may appear.

Appropriate watering is, of course, essential to the establishment of the new lawn.

If you are interested in seeding your yard, St. Augustinegrass is not recommended because it takes a long time for it to get established, insufficient research on recommended varieties and unavailability of seed.

Sowing Bermudagrass seed is an option, though, if you are not planting in shaded areas. Local lawn and garden stores carry Bermudagrass seed and the Internet offers many sources.

If you choose to seed, do not use a pre-emergent herbicide, as it will prevent the germination of the Bermudagrass seed also. Before sowing the seed, use a grass rake to loosen up the soil surface. Follow the label for application rate. As with the sodded lawns, frequent watering during establishment is essential.

Spot Problems

If you have determined that your lawn generally survived and is starting to green up, you may notice some smaller circular areas that are not rebounding as quickly as your lawn in general. This may be caused by an infestation of brown patch.

If the stolons are green, but the blades of grass are dead, this area of your lawn will come back, but it will take longer.

To remove the dead plant material, just take a leaf rake and rake through the area from a couple of different directions. This will clean the infected area and neaten it up a bit.

If you have small areas where the stolons and roots are dead, you must remove the dead grass before repairing the area. Once the area is cleared, you can purchase sod and fill the area in entirely or you can dig plugs from healthy areas in your lawn and plant those in the affected area. Again, keep the area well-watered.

Other Tips

Weeds are very opportunistic and can become a major problem in weak turf. It is too late to apply a pre-emergent for spring weeds, but a broadleaf weed killer will take care of dandelions, thistles, clovers and other weeds. Just follow the directions on the label.

Poanna, or annual bluegrass, has been especially virulent this year. It is very prolific and sprouts many seed heads growing only four to six inches tall. Mowing can help control it. A pre-emergent applied in October will help control this pest for next year.

And finally, a local turf grower has suggested that it may be helpful to use a fertilizer with a lower percentage of nitrogen (the first number on the bag). This will help the plant develop a better root system and put less stress on the grass.

But the best advice is to follow results from a soil test

1. Remove dead thatch or grass without damaging the living stolons.
2. Do not leave excessive dead plant material on the lawn.
3. Replace with recommended grass variety.
4. See 3-year local grass variety demonstration results
5. Control weeds.
6. Use a balanced fertilizer to stimulate root growth.
7. Fertilize and water as needed.
8. Be patient. Recovery may take some time.

April 26 - Rainwater Harvesting
May 10 - Xeriscaping
June 14 - Cacti and Succulents
July 12 - Mulching and Composting
August 9 - Planting a Fall Vegetable Garden