Avoid the need for weed preventers by keeping your lawn healthy. Once established, only water your turf once a week during the growing season. Up to 1 inch of water during this watering session allows roots to search deeply for moisture to create strong grass. Shallow grass roots die in stressful conditions, like drought, and allow weeds to grow in thinned spots. Allow your turf to grow to a healthy height as well, typically between 1 and 3 inches, depending on the species. Long grass blades mean the grass can produce enough energy to stay healthy and compete with weeds. In short, healthy and well-maintained grass has less problems with weed growth.
Spreading seed is an inexpensive way to grow a lush lawn, but exposed soil between germination and establishment makes it vulnerable to weeds. Although chemical weed preventers have different mixtures and instructions, you should not apply them while seeding or immediately afterward. You must allow one to four months between applying this type of chemical and spreading seed.
Chemical weed preventers, also called preemergent herbicides, are usually granules or liquids, but both require water to work. As the preventer soaks into the ground, it leaves a residual film in the top 1-inch of soil. Because most seeds germinate at or just below the soil’s surface, these preemergent herbicides remain active against any germination processes for up to four months, depending on the chemicals involved. Organic weed preventers work in a similar way. With many weeds being members of the grass family, all seeds, including desired lawn species, fail to germinate and sprout after you’ve used a weed preventer.
Cool-season grasses are usually seeded, as opposed to warm-season grasses that usually need to be grown from sod or plugs. Because cool-season grass seeds germinate best in fall, apply your chemical preventer in spring to actively kill off weeds in spring and summer. In general, temperatures between 65 and 70 degrees Fahrenheit are good for weed preventer application. Hot days often cause the chemicals to vaporize into the atmosphere, reducing their effectiveness. By the time fall seeding weather arrives, the chemicals are no longer active and the grass seeds will be able to sprout.
Even if you time your weed preventer and seeding periods correctly, you need to do the job right to get an even lawn with no bare patches. Apply seeds uniformly across your yard using a drop spreader on a mild fall day. Spread up to 1-inch of organic mulch over the seeds to conserve moisture and encourage germination. Water the seeds at least twice a day for short, 10-minute sessions. You do not want to wash away the seeds, but they need consistent moisture to grow. Hand pull any weeds that appear while the grass seedlings develop. Do not apply any chemicals for weed control.
Writing professionally since 2010, Amy Rodriguez cultivates successful cacti, succulents, bulbs, carnivorous plants and orchids at home. With an electronics degree and more than 10 years of experience, she applies her love of gadgets to the gardening world as she continues her education through college classes and gardening activities.
Grass struggling to grow from a new establishment cannot smother weeds. Because there is no grass seed that kills weeds, it may be necessary to use herbicides on weeds so that your grass has a chance to populate the planted area. Your new grass needs time to establish itself before any herbicides are applied – you could possibly kill off your new grass with too much chemical exposure.
Battling weeds in your yard is an ongoing fight, especially if you have bare, patchy areas in your lawn – weed seeds quickly germinate in the sunny, exposed soil, preventing your turf from populating the space. You cannot smother weeds with a new grass establishment, whether from seed, sprigs or sod, since both species will compete for soil resources. Grass clippings spread on weeds as a mulch, however, may curb weed seeds from germinating. Practice consistent maintenance on your established lawn, such as proper mowing, to help deter unwanted plants.
You cannot smother weeds with a new grass establishment, whether from seed, sprigs or sod, since both species will compete for soil resources.
Watering and Mowing
But you need to carefully remove any portion of perennial weeds from the ground. Leftover root parts broken off from the main weed easily proliferate into new pesky plants. You may need to repeatedly hand-weed the turf of these perennials, especially if they had a chance to spread seed.
Applying a 2- to 3-inch grass clipping layer across your weeds does not typically smother them – weed foliage still has ample sunlight and soil resources to grow steadily. This smothering mulch technique, however, does help you prevent weed seed germination. Seeds that do not have access to sunlight cannot properly develop into hardy seedlings.
One of the best ways to smother weeds is to keep your soil healthy for thick grass growth. In general, your grass needs a soil pH value range between 6 and 7. With a slightly acidic range, some weed seeds cannot survive in these conditions. Proper fertilizing approximately three times each year keeps the soil prime for grass growth as well, according to the University of Rhode Island – sunlight cannot reach the soil where weed seeds germinate if the grass shades the soil. A fertilizer with a 3-1-2 ratio of nitrogen, phosphorus and potassium is sufficient for most grass species.
Some weed species are bound to invade your turf, so it is critical to remove these sprouts as soon as you find them, recommends University of Maryland. Neglecting even one weed causes stress to your grass as it steadily grows. Annual weeds do not create extensive root systems – hand-pulling them directly from the soil typically removes all traces of the plant.
While you may think lawn maintenance and frequent use of your mower is to keep your neighbors happy and pests away, think again. It actually helps your grass stay strong. When you forego mowing, and your grass grows to excessively high levels and goes to seed, you're doing more harm than good. Much of the grass seed that pops up on the tips of the blade may actually be sterile-so don't expect bare patches to miraculously fill in. And, when you do mow, you're not following the one-third rule, which lawn maintenance professionals know to be "not cutting off more than one-third of your grass blade during a mowing session." If you hack the mower blade through the tender grass and cut off more than one-third of the stem, it will significantly weaken your grass.
Weeds are pesky. They grow quickly and can be tough as nails to remove and dissipate from lawns. When you let your grass go to seed, you're actually letting weeds grow, eliminating any control you had over them. Mowing frequently cuts the weeds down and weakens them in their ability to grow back. Letting them rise high and proud in your yard will ensure your grass will be filled with more broadleaf weeds and creeping Charlie than ever.
Creating the flowering seed is a lot of work for each blade of grass. When you let your lawn go to seed, you're letting it divert energy it would normally use to grow strong and healthy, and let it instead concentrate on flowering. It will also signal to the grass that it doesn't need to produce as many beneficial rhizomes, leading it to stop repairing itself, and essentially making your lawn look worse.
Sometimes, you just don't want to pull out the lawn mower. It happens. Mowing grass can be tedious and time consuming, and it's tempting to let your grass grow"¦and grow"¦and grow. Unfortunately, your grass will eventually go to seed and the long blades won't just be tough on your mower; they'll also be tough on the entirety of your yard. Letting your lawn go to seed won't be the same as planting new grass seed that creates a brand new lush lawn. There are three specific dangers in letting lawns go to seed.
The next time you think you'll let your grass go to seed while on vacation, or are tempted to let your front yard turn into a prairie, remember these three dangers. If necessary, look into hiring lawn services to take care of your yard.