Grassy weeds are considered some of the most difficult weed control problems to deal with in lawns. Biological similarities between grassy weeds and the grass you have on your lawn make it challenging for weed control manufacturers to produce effective weed control products. Broadleaf weeds, on the other hand, have biological aspects to them that are much more different than what you see in lawns and grassy weeds. This provides weed control manufacturers a wider array of bio-targets to go after when creating a pre or post-emergent herbicide for broadleaf weeds. Because of these factors dealing with grassy weeds can be quite problematic. In lots of cases, applying herbicides to kill grassy weeds will also result in killing healthy lawn and turf, and therefore the best solution to preventing grassy weeds is before they start by regularly using pre-emergent herbicides. There are also selective herbicides that can be used to target certain grassy weeds in lawns, that won’t kill your grass, but these products can be expensive and difficult to apply.
What Are Grassy Weeds?
Grassy weeds are types of invasive species that resemble grass and turf. Crabgrass and dallisgrass are two notorious examples of grassy weeds that can overrun healthy turf. These types of weeds crowd out healthy, desired species and compete for water, nutrients, and sunlight. Grassy weeds can spread very quickly if not eradicated within a reasonable amount of time.
Common Examples of Grassy Weeds
Crabgrass can be tricky to identify because it can adapt to its environment to some extent. When it first emerges, crabgrass can resemble miniature corn stalks. Its leaves are typically wider than 1/4,” and it grows quickly in shoots out from the stem, which then grow out as separate branches. As the stems get larger, they appear to form a sort of star pattern. As crabgrass matures, it sends out shoots or runners to establish more territory. It can put down roots at each node as it spreads, making it more difficult to remove the weed as it spreads. At each node, it can grow more branches up and out, which then has the potential of smothering out existing healthy turf.
Dallisgrass is a grassy weed will that will continue to reemerge in your lawn year after year because it is a perennial weed. This weed is often confused with crabgrass with bright green foliage. Like crabgrass, dallisgrass sends out runners where it continues to spread and invade healthy turf. At each node, it can put down more roots so it can continue to grow if one root gets cut. It has no problem growing in low lying clumps on lawns that are mowed but can get up to 14-inches tall. This weed is notorious for crowding out desired grass.
Annual Bluegrass or Poa is another common grassy weed frequently found in Georgia. This undesired lawn guest is an annual grassy weed, meaning when the weather turns cooler, it will die instead of merely going dormant. However, this does not necessarily make it easier to eradicate in turf. Bluegrass can thrive in cooler, shady, damp spots. Once the weather turns hot and dry, however, this type of grass will often die, leaving dead, brown patches in your yard. It also forms dense patches that can withstand short mowing heights.
Yellow nutsedge or Yellow nutgrass are also among some of the most problematic weeds and are common in Georgia. These perennial weeds are difficult to control because it reproduces underground through a series of tubers. A single plant can produce several hundred tubers, making it an extreme threat to surrounding turf. It is most noticeable in the summer because its leaves grow faster than the turf in the hottest summer months. However, in the spring and fall, it is more difficult to spot because it tends to grow at around the same rate as surrounding grass. Its leaves are arranged in groups of three, making it easier to separate from other healthy lawns.
Weed Control of Grassy Weeds in Turf
Grassy weeds present a particular challenge to both homeowners and lawn care companies because of the types of treatments they require. There are a limited selection of weed control products that can single out specific species of grassy weeds that won’t harm existing healthy turf.
Pre-emergent herbicide applications are among the best ways of battling grassy weeds by stopping them before they start. Pre-emergent treatments should be done based on grass type and include applying an herbicide that activates in the top layer of soil. Pre-emergent weed control treatments aren’t a miracle cure, however, and need to be followed up with other treatments. It is also important to note that when applying pre-emergent herbicides, you will be unable to start seeding your lawn (if you need to fill sparse spots) after the pre-emergent chemicals have been used.
Post-emergent treatments are applied after weeds have already been established. The sooner they are treated, the better. Post-emergent weed control treatments utilize herbicides to broadly treat or spot-treat weeds. There are a few different post-emergent treatments:
Systemic herbicides are typically used for treating perennial weeds. These weed control products are applied directly to the plant where it is absorbed and moves throughout the plant for maximum elimination.
Contact herbicides may be used on annual weeds. When it is applied to the foliage, it shrivels up and dies. For many annual weeds, killing off the foliage is enough to eliminate the entire weed.
Weed control treatments may also be classified into selective and non-selective treatments. Selective treatments are most often used on grassy weeds because contact with other healthy plants is unavoidable. Non-selective treatments are only used for broad-spectrum weed control.
Long-term Lawn Care For Grassy Weed Avoidance
To keep your lawn healthy, there are certainly some steps to help avoid the emergence of grassy weeds. A complete lawn care plan can help tackle those pesky weeds and keep your lawn healthy, lush, and the envy of every neighbor in town. Cultivating a thick, dense, high-quality turf will also help prevent the emergence of grassy weeds, and utilizing the services of a professional lawn care service that provides weed control can certainly help. To help keep grassy weeds at bay, take the following steps:
1) Apply pre-emergent weed control according to the instructions on the package. This will prevent weeds from developing.
2) Fertilize. This is particularly important as your grass wakes up from winter dormancy and begins to come to life for the season. During this time, it is essential to add another application of pre-emergent weed control according to the instructions, as well. A broad-acting herbicide may be a good idea at this point as well as a long-lasting fertilizer that will nourish your lawn.
3) Water less frequently but for more extended periods in the morning. A good, deep watering will encourage deeper roots for your grass. This also allows the soil surface to dry out completely between watering, which is an excellent deterrent for grassy weeds.
4) Mow to the proper height. Close-cropped lawns may look inviting, but they are also more susceptible to crowding out of healthy turf as weeds take hold. Longer grass, however, can make it difficult to completely dry out the top layer of soil and also cultivate more weeds. The ideal height to mow is between 2-2 1/2″ long.
Grassy weeds are the bane of many homeowners’ existence. For those who have little to no experience with these invasive weeds, it may appear to be a normal part of taking care of a yard. It isn’t until healthy turf begins getting crowded out and walking barefoot on the lawn becomes physically painful that many novices even know there is a problem. Once grassy weeds start to rear their ugly heads, there is often already an established problem. It can be eliminated with a lot of time, patience, and persistence. Of course, contacting a reputable lawn care company to help fight the battle of grassy weeds can give you the proper weed control you need.