If your lawn is overtaken with flowering dandelions, ugly tufts of crabgrass, or sprawling ivy, it may be overwhelming at first. If you’re currently facing this situation and want to know how to get rid of a lawn full of weeds, the following guide will walk you through all the steps of weed identification and effective strategies for weed control in lawns.
There are several options for how to get rid of weeds without killing grass. Whether you’re facing a host of broadleaf weeds or invasive grasses, a holistic lawn solution will promote grass health and eliminate weeds.
Different Types of Lawn Weeds
The first step in restoring a weed-infested lawn is determining what weed types are currently overrunning your yard, as well as the life cycles of these weeds. If you’re looking for a way to reclaim your lawn covered in weeds, this knowledge is essential.
As the name implies, grassy weeds are part of the grass family. Because of this, many tactics for killing grassy weeds may be harmful to desirable grasses. Grassy weeds can be identified by the following traits:
- Blade-like leaves with a central ridge but no visible veins.
- No flowers. Grassy weeds do not produce flowers or attract pollinators.
- Long, hollow stalks with wheat-like seed heads at the end.
Dandelions, ivy, chickweed, and clover weeds are all members of the broadleaf weed family. These species cover a wide range of growth patterns and can be resistant to traditional weed treatments. Here are some traits to look for when identifying broadleaf weeds:
- Veined or lobed leaves, similar to garden herb and vegetable plants.
- Flowers and pollinators. Almost all species of broadleaf weeds flower in spring and/or summer.
- Dead flowers that have turned to seed heads. A common example would be the dandelion’s transformation from yellow flower to fluffy, white seed head.
Weed Life Cycles
When deciding how to clear a yard full of weeds, it’s essential to know the life cycles of the plants you’re fighting. Different tactics, herbicides, and seed-control measures work best against weeds with different life cycles.
Weeds that persist year after year are known as perennial weeds. While these plants may appear to “die-off” in the fall or winter, they are merely entering a period of dormancy before reviving in the spring.
Emergent weed killers are an effective means to kill perennial weeds in your lawn.
Common examples of perennial weeds are:
- Broadleaf weeds such as dandelions, clover, and ground ivy.
- Grassy weeds, such as bermudagrass, quackgrass, and orchardgrass.
Weeds that grow in a single year, drop their seeds, and then die are known as annual weeds.
Pre-emergent solutions, which prevent seed germination, are often the best way to kill annual weeds.
Common examples of annual weeds are:
- Broadleaf weeds such as chickweed and pigweed.
- Grassy weeds such as crabgrass and foxtails.
Biennial weeds live for two years. In the first year, they grow leaves and root systems. Then, in the second growing year, they produce flowers and seeds before dying, much like annuals.
Because biennials exist in a middle ground between annuals and perennials, emergent weed-killing methods and pre-emergent seed-halting measures can both be effective.
Common biennial weeds include:
- Broadleaf weeds like thistle and poison hemlock.
- Note: There are no true biennial grasses or biennial grassy weeds.
How to Get Rid of a Lawn Full of Weeds
The goal of a homeowner is to learn how to kill weeds and grow grass. There are also multiple methods for getting rid of weeds in your lawn. Below we will discuss:
- How to kill weeds using herbicides.
- How to kill weeds the all-natural way.
- How to improve lawns and gardens to create a weed-resistant yard.
Read on for step-by-step guides on how to revive a weedy lawn.
Step-by-Step Guide to Killing Weeds with Herbicides
Kill Isolated Weeds
For weeds in isolated areas, the best lawn weed killer is spray bottle herbicide. Broadleaf-specific herbicides will kill plants such as clover and dandelion while leaving grasses unharmed. However, broadleaf-specific herbicides often won’t kill grassy weeds.
Some grass-killing herbicide sprays may also harm lawn grass, but if you are treating isolated patches with a spray bottle, this is less of a concern. See step 2 for information about selective herbicides that kill broadleaf weeds and grassy weeds while preserving turf grass.
Treat Full-Lawn Weed Invasions
So, you have a yard full of weeds? Perhaps there’s even a mix of broadleaf weeds and grassy weeds. After all, it’s not uncommon to see clover, dandelions, and crabgrass all competing for space in the same yard. Never fear, there’s a solution for you.
For immediate weed-killing results, we recommend applying a herbicide containing Quinclorac, which kills many species of broadleaf weeds, while at the same time, eliminates grassy weeds. It’s also safe to use on most species of desirable turfgrasses. Professionals use it to maintain golf courses and athletic fields.
Begin a Herbicide Schedule
We recommend applying your herbicide of choice twice per year. The first application should be in spring between late-May and late-June. The second should be in fall between mid-September and early-November.
Quick tip: Water your lawn before applying herbicide. This allows herbicides to adhere to weed leaves and pulls herbicides into the soil to attack root systems.
Prevent Future Weeds from Sprouting
Even if you’ve rid your lawn of all visible weeds, this doesn’t mean more weeds won’t arrive. Emergent herbicides won’t harm seeds and any unsprouted weed seeds are a threat to lawn health.
In order to stop weeds before they sprout, apply a pre-emergent herbicide containing isobaxen. It will prevent both broadleaf and invasive grasses from sprouting. April is typically the best month to apply a pre-emergent herbicide. Waiting any later will allow seeds to sprout, and pre-emergent herbicides won’t kill living plants.
Quick Tip: Don’t apply pre-emergent herbicides if you have recently seeded your lawn or if you plan to seed your lawn within the next 3 weeks—it will prevent grass seeds from sprouting.
Step-by-Step Guide to Killing Weeds the All-Natural Way
Spot-Treat Weeds with Vinegar
Because hand-digging weeds is time-consuming and not always effective, it pays to mix an all-natural weed killer yourself. The recipe and technique are as follows:
- Fill a spray bottle with vinegar that has 10–20% acetic acid (This stronger vinegar is available at most hardware and garden stores).
- Add a dime-sized portion of dish soap.
- Shake the bottle to mix the contents.
- Thoroughly spray the leaves of any weeds and grasses you wish to kill.
The dish soap helps the vinegar adhere to the leaves, destroying them. Unfortunately, you may need to apply several applications because vinegar won’t kill the entire weed plant.
Quick tip: This mixture will also kill desirable plants and grasses, so be sure to apply it to weeds only.
Use Natural Weed Killers to Control Lawn Invasion
Stopping weeds that have overtaken an entire lawn is no easy task. Applying vinegar can work in isolated areas, but may not work when you want to fix a lawn full of weeds. What you want to do is kill weeds, not grass.
There are several natural weed killers that target broadleaf weeds specifically. Fiesta and Iron-X are iron-based weed killers. A.D.I.O.S. is another popular natural weed killer. It targets broadleaf root systems to kill weeds. Keep in mind, all of these options are emergent weed killers, meaning they will only kill weeds that have sprouted.
You can also use these natural weed killers in your yearly lawn care schedule. Simply apply them to your yard in spring and summer, as you would with a chemical herbicide.
Employ Natural Methods to Stop Weeds from Sprouting
Looking for a natural way to stop weed seeds from sprouting? Cornmeal Gluten is the answer. It dries out seeds, preventing them from germinating and taking root. Most natural pre-emergent weed killers contain Cornmeal Gluten (also known as Corn Gluten Meal or CMG).
Be sure to apply Cornmeal Gluten in spring (when soil temperatures are around 50℉) to prevent seeds from sprouting. Corn Gluten Meal dries out seeds, stopping them in their tracks. It will stop broadleaf seeds as well as grassy weed seeds. However, if applied too late, CMG will act as a natural fertilizer, so start early!
As with chemical pre-emergent herbicides, CMG doesn’t discriminate. It will also stop grass seeds from sprouting. Do not apply if you have young grass seedlings (wait until they are mature enough to have been mowed 2–3 times) or if you plan to seed your lawn within the next 3 weeks.
Step-by-Step Guide to Create a Weed-Resistant Lawn
If you find yourself asking, “how do I improve my lawn full of weeds?” the answer is right under your feet—grass. Healthy grass is a natural weed-fighter. Strong roots and thickly growing blades stop weeds from sprouting and prevent sunlight from reaching pesky seedlings.
Feed Your Lawn
You can prevent weeds and fertilize your lawn simultaneously by applying one of the best Weed and Feed fertilizers on the market. These combine herbicide with fertilizer as a one-stop product.
If you want to fertilize your lawn naturally, most home and garden stores carry organic and natural fertilizers formulated for lawn health. Additionally, aged chicken manure, as well as compost including alfalfa or horse manure are great natural options.
Whatever fertilizer you choose, make sure that it is a “slow-release” fertilizer. Slow-release fertilizers introduce nutrients into the soil over a 6–8 week period. This promotes the growth and long-term health of your grass.
The average lawn should be fertilized twice per year (spring and fall). Over-fertilization, especially with the use of quick-release fertilizers, can backfire. “Burnt” dead patches in your lawn can result, and dead patches are prime territory for weeds to take root.
Aerate Your Lawn
Most lawns become ripe for weed takeover because the grass is unhealthy and can’t fight back against the invading weeds. The most common culprit of sickly grass is poor soil quality.
Aeration is one of the best ways to improve soil quality. It is great for decompacting hardened soil, integrating sod soil with the dirt beneath, and clearing out thick thatch that might be choking the life out of your grass. An aerator can be purchased or rented from most hardware stores.
Aerate your lawn in the growing season (typically in April). This will allow your grass to take advantage of the improved soil. Don’t worry, aeration won’t interfere with any weed-killers you’ve applied.
Water Your Lawn (The Right Way)
Your lawn needs 1.5 inches of water per week. As a rule of thumb, the average sprinkler delivers about 1 inch of water in 1 hour. Below are some guidelines for proper lawn watering.
- Water deeply 2–3 times per week. This allows water to penetrate the soil and encourages grass root growth. Deep roots allow grass to survive droughts and heat.
- DO NOT water daily. Watering for a brief period each day encourages shallow root growth, leading to weak grass that is likely to yellow or die during the summer heat.
- Subtract rainfall. If your lawn is getting water from natural precipitation, alter your watering schedule accordingly. Overwatering can be detrimental to your yard’s health.
Use Good Mowing Practices
Grass, like all plants, relies on sunlight for growth. It collects sunlight through its blades. The optimal grass height after mowing is 2.5 inches.
By mowing at one of your mower’s top settings you will ensure that your grass has long enough blades to maintain good health. Low mowing puts stress on your grass and weakens it, making it much easier for weeds to invade and thrive.
It may be tempting to mow grassy weeds like crabgrass at a low height in an attempt to chop seed heads. However, this is ineffective. Crabgrass will begin to grow horizontally and even produce seed heads at ground level. Continue optimal mowing practices even when dealing with weeds.
Protect Your Garden
Your lawn is one thing, but your garden is another. Often, invasive weeds and grasses emerge in flower beds where desirable grass isn’t present. These grass-free areas can serve as a beachhead for weed invasion.
To keep your garden weed-free, use mulch or rocks to cover the ground between your garden plants. This will inhibit weed growth and save you the trouble of combating harmful weeds.
When creating an all-natural and chemical-free yard, it’s important to consider the garden as well. Many commercial mulches include chips from chemical or pressure-treated lumber. During rain or watering, these chemicals leech out of the mulch and contaminate your soil. If you wish to avoid this, purchase organic mulch. Alternatively, consider using rocks, pine needles, or straw instead.
Maintaining Your Weed-Free Lawn
The best weed killer for lawns is a plan that combines several weed treatments. The main components of any good lawn weed control plan are:
- Identify the weed type(s) in your yard
- Kill existing weeds
- Prevent new weeds from sprouting
- Promote lawn health to keep weeds out
As long as you take steps to address these four points, you will reclaim your lawn, keep it weed-free, and see your grass grow healthier than ever before.