by OCMGA Master Gardener Vicki Schilleman
Everyone wants the perfect sea of smooth green lawn with nary a hint of weed, bare spot, or discolored grass. Alas, easier said than done! However, here are 5 steps that will help create a beautiful and naturally weed-resistant lawn.
- Prepare the soil. Though they are seldom thought of that way, expanses of mown grass are actually very intensive gardens. Loose, fertile soil of the right pH is even more important for good lawns than it is for tasty tomatoes or lavishly blooming shrubs.
- Invest in the best seed, use enough of it, and plant it at the right time. The first defense against weeks is a turf that is thick enough to prevent them from getting the light they need to sprout and grow. The grass won’t be thick if you’re stingy with either quality of quantity, and it won’t fill in properly unless you give it a proper start.
- Think long term. Be sure the seed mixture comprises grasses that will be long lived, such as red fescues and bluegrasses. There should be only a very small amount of rye grass, if there is any at all. Rye grasses grow quickly, helping the lawn to look good fast and preventing the growth of some weeds. But because they are up so quickly, they steal nutrients, water, and light from slower-growing but more durable types. As a result, newly established turf has a lot of rye in it. This is fine for a short while. But even perennial rye dies out within a few years, and when it does it leaves a whole lot of room for weeds to move in. A sprinkling of rye can be used if you are the impatient type. But you’ll have better long-term weed control if you go for the slow stuff and hand-weed for the first year or so while the good grasses are settling in.
- Adjust the mower to the season. No matter what height you like your lawn, letting it get a bit shaggy in summer — a good 3 inches tall — will cut down on weeds. The taller gras provides more shade, keeping the grass roots cool and healthy while making it harder for weed seeds to sprout and find the light.
- Don’t water if there’s a drought. This may seem counterintuitive, and it isn’t entirely true: if you have an endless supply and can water the lawn thoroughly, by all means go ahead. But if water is limited, you’re much better off letter the lawn go dormant than trying to give it “just enough to stay alive.” Grasses naturally lie low and turn brown during droughts. They aren’t dead — they’re just sleeping. A small amount of water won’t be enough to keep grasses green, but it will keep the lawn green, because the watered weeds will thrive
Organic Weed & Feed
For those of us who become frustrated at the growth of weeds in our lawns when we’re using organic fertilizers, there is one help: corn gluten meal, a by-product of corn milling. It is quite high in nitrogen, which makes it a good fertilizer for grass. And it will prevent weed seeds from growing.
But — there’s always a but — that’s it. Corn gluten kills by drying up the baby sprouts as soon as the seed cracks open. It has no effect on perennial weeds (other than to encourage them) or on annual weeds that are already growing.
Furthermore, it must make good contact with the weed seeds in order to kill them, not a problem on bare soil but a tricky proposition if the grass is reasonably thick. It works best when the soil is warm, by which time many annual weeds have long since been up and about. And it lasts for only about six weeks, so you have to apply it frequently.
All that said, corn gluten is a relatively benign fertilizer, and it can help control annual weeds if you use it faithfully, from spring to fall, for a couple of years. It is nontoxic and, in home-garden quantities, safe for the environment.