A Weed-Free Lawn, In Just Three Key Steps

Your lawn can be self-weeding—and a self-weeding lawn has just got to be the ultimate in any homeowner’s dream world. The best part is, it’s not all that difficult to obtain. There are only three steps necessary, but each is important in making your lawn self-weeding—and it does take patience.

First: Seed your new lawn, or renovate your old one with new, improved named grass varieties—and do it in the late summer to early fall, NOT NOW. There are bluegrasses, several fescues and perennial ryegrasses to choose from, and each has its pluses and minuses. Blends and mixtures are readily available, and several local garden centers have “house” blends or will create a blend that will provide the best chance of success. These are suitable for the establishment and maintenance of disease- and insect-resistant lawns that are vigorous enough to crowd out seedling weeds before they get a start.

Second: Have a soil test taken so you know how much lime and fertilizer are needed. Don’t guess. These new grasses are well worth the extra care to see that good, healthy roots develop deep into the soil.

You should maintain a soil pH of about 6.5 with the use of limestone, and the lawn grasses must be fertilized with enough but not too much of the right fertilizer for your soil. Two to three pounds of nitrogen a year per 1,000 square feet is a common recommendation, but most lawns can now do very well with as little as 2 pounds of nitrogen per 1,000 square feet a year, especially when you recycle your grass clippings by using a mulching mower (or insist that your lawn company does).

When these conditions are made right, lawn grasses are healthy, and weeds simply cannot compete.

I’ve seen public park and school athletic fields that are properly fertilized and over-seeded regularly, and they look great without the use of herbicides.

Third: There are other cultural practices that must be made right. These include clipping height and irrigation.

Close mowing and improper watering both keep roots near the soil surface, and this is detrimental to vigorous turf. The use of lawn fertilizers in the spring also is a bad practice, since this encourages blade growth at a time when you need to be encouraging root growth.

Mow frequently at a height of 2 to 3 inches, depending on the type of grass, and water infrequently but deeply to encourage the type of turf and root development that will keep weeds from ever establishing.

Weed killers are just not needed on a self-weeding lawn, but should the need arise, virtually all weed control can be done as spot treatments, with the possible exception of crabgrass control.

The objective of chemical weed control is the elimination of the largest number of weeds with the fewest possible repeat treatments (unless you’re in the business of selling and applying herbicides). This means that the proper chemical must be used at the right growth stage of the weed, at the correct concentration, to achieve control at the right time of the year. There must be adequate coverage of the weed for effective penetration into the soil or onto the plant. For soil-active weed killers, the chemical must be properly placed and distributed within the upper soil layer or root zone.

Perennial weeds, such as dandelions, can be a bit more difficult to control than annual weeds, such as crabgrass. And don’t be duped: There is no point in trying to control crabgrass once it has set seed during the summer. Sure, you can kill the existing plant, but what’s the point? Next year’s seeds have already hit the ground and are eagerly looking forward to next spring.

The key to crabgrass control is the word “pre-emergent.” This is an herbicide that kills the plant just as it germinates. While most people and lawn care companies will use chemical pre-emergents, there is an organic one available that is derived from corn gluten (a corn processing byproduct) that, if used correctly for several years, can reduce your crabgrass by close to 95 percent. Better still, it also acts as an organic fertilizer.

Weed identification is very important. Some weeds are easy to control, while others are difficult. The first step in proper use of an herbicide is to be certain that the weed is accurately identified and you (or your landscaper) know that the chemical weed killer purchased will give effective control of that weed. Purchase a lawn care booklet, or go online to find a picture key that features lawn weeds. Check at the garden center for charts and leaflets that contain pictures and sketches of common weeds. Know your weeds before trying to control them, and know when to control them.

Some of the more difficult weeds to control are wild onions (aka wild chives) and nutgrass. In both cases, homeowners are always baffled when they believe they’ve pulled them all out, only to find that these two weeds return with a vengeance. This is because when they are yanked out of the ground, you are usually leaving behind the tiny bulbs and nuts, the important reproductive parts of the plants, which you’ve just stimulated to regenerate.

Chrysanthemum weed (aka mugwort) also is a difficult perennial weed that usually grows on the periphery of the lawn and in open spaces. Pulling this darling out rips up the roots, and each tiny bit of root left behind grows a new plant.

I think that in all three cases the appropriate use of an herbicide is the best control method.

Among the easiest weeds to control are crabgrass and dandelions. Crabgrass responds really well to a pre-emergent, so long as it’s applied at the right time, which out here is usually mid- to late April. And dandelions respond well to 2,4-D, an herbicide that’s been around for as long as I have; 2,4-D and its relatives do have critics, and some of you may not want to use it. But years of research, some of it very recent, indicates that when used correctly it’s both safe and effective.

When using any herbicide, read and follow the label directions exactly as printed. Don’t think that if it says to use a half ounce to a gallon of water, using a full ounce to a gallon will act twice as fast or kill twice as much. In all likelihood, such indiscriminate use will kill your lawn and weeds alike.

In the vegetable garden, mulches are the best bet for weed control, especially in organic gardens. Don’t skimp—mulches need to be a couple of inches thick to be effective. Corn gluten also can be used in the vegetable garden as a pre-emergent, but remember that it also will prevent many of your vegetable seeds from germinating. This is an important consideration with seed crops like lettuce, carrots and others.

In the flower garden or border, mulches are also critical, but many gardeners use a herbicide with the trade name Preen. Preen is a pre-emergent brand as well and can be bought under that name or as the less expensive generic, Treflan (Preen’s active ingredient).

And remember, the object is always … to keep growing!