Crabgrass. The very name of this creeping weed gives creeps to many lawn carers. The feisty, unsightly, aggressive grass seems to appear out of nowhere and smothers the domesticated turfs we put so much effort into.
It is no wonder that you feel ready to reach for just about anything to destroy it. However, as people are becoming aware of the dangers of synthetic pesticides, many are wondering how to get rid of crabgrass naturally?
Does crabgrass instill a degree of terror in you? I don’t blame you. I’ve felt this way myself when I would find crabgrass suddenly lurking around in the hidden corners of my yard.
However, people usually fear what they do not know.
Let’s get to know crabgrass better so we would fear it less, and most importantly, to learn how to conquer it naturally, without any risk for health or the environment.
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- What is Crabgrass?
- Why is Crabgrass Bad?
- Why Kill Crabgrass Naturally?
- How To Combat Crabgrass Naturally
- Crabgrass Prevention
- Killing Crabgrass Naturally
What is Crabgrass?
Crabgrass is actually not one species of grass, but an entire genus called Digitaria, consisting of more than 30 species!
Luckily, there won’t be 30 different species of crabgrass invading your lawn. Only two of them are very common and considered weedy in North America – the Large Crabgrass (Digitaria sanguinalis), and Smooth Crabgrass (D. ischaemum).
However, since they act pretty much the same, we will call both of them by the singular unifying name – crabgrass.
Crabgrass grows in a creeping fashion, with runners spreading radially from the center. The circle that single crabgrass can form can reach up to 12 inches (30 cm) in diameter. Its Latin name comes from the word digits, aka fingers, which tells a tale about the look of its flower clusters.
Those flowers are not just for fun and easier plant identification. Each tiny flower produces a seed. And a single crabgrass plant is capable of producing 150,000 seeds per season.
Yes. One plant. 150,000 seeds.
But seed explosion and vigorous growth are not the main reasons behind crabgrass infestations. The key is that crabgrass predominantly appears in poorly maintained lawns, which is really important for the rest of our crabgrass story.
Why is Crabgrass Bad?
Crabgrass is not bad per se, it’s just not a desirable grass species to have on your lawn, even if it’s a mixed-species one.
Despite being a tough, resilient grass, and very nutritious forage for cattle, the way crabgrass grows makes it highly unsuitable for forming lawns. It is unable to form a uniform cover; instead, it grows in bumpy clumps (sounds cute, but it isn’t!). Its aggressiveness is also a drawback for having it as a cover in gardens.
There are several reasons why people don’t want it on or near their lawns.
Crabgrass Growth Habits
This type of grass grows – or to say it better, it creeps – horizontally from one center, so it looks unsightly. On top of it all, it grows aggressively, so if left unchecked, it will smother the original turfgrass.
Crabgrass Seed Production
As said before, a mature crabgrass plant can produce over 100.000 seeds which can remain viable in the soil for almost a decade. That means that if you let the momma crabgrass seed, you may end up with a persistent weed problem for years to come.
Crabgrass Longevity – Or the Lack of It
Crabgrass is an annual weed and it dies completely at the end of its life cycle. While that may sound like a good thing, because who wants the same weed to return year after year in the same spot, dead crabgrass will turn yellow-brown and spoil the consistent look of a perennial green lawn.
Besides that, crabgrass that was allowed enough to naturally die has already produced tens or a hundred thousand seeds that will germinate the moment they get some spring sunshine and warmth. And it is precisely these bald spots where the mother-plants have died that are the ideal for the sprouting of the new crabgrass generation.
Why Kill Crabgrass Naturally?
There are many commercial synthetic weed killers (herbicides) on the market, which are surely efficient in killing weeds, including crabgrass. However, using chemicals on crabgrass is far from an ideal solution.
Here is why you would want to avoid using regular weed killers for crabgrass.
Herbicides Might be a Remedy, But Not the Solution
Remember the common saying “treat the disease, not the symptom”, which is the epitome of good health care? The same applies to lawns stricken with crabgrass.
Crabgrass invades thin lawns, cut too low, underwatered, under-fertilized, and poorly drained. Essentially – whenever there is a poorly maintained lawn, crabgrass will eventually start to take over.
Therefore, using weed killers is not a final solution to the problem. As long as the conditions are not right, it will keep returning. It’s a bit like trying to treat a broken arm with painkillers.
Weed Killers Come With Problems
Sure, you may say that simply spraying weed killers is easier than making sure your lawn is always in top condition, however, that ease may come with a price – and not just what you pay with money.
There are serious, scientifically-founded claims that glyphosate, one of the main ingredients of many commercial herbicides, is carcinogenic. In a groundbreaking court ruling, a couple was awarded 2 billion dollars in punitive damages for getting lymphoma, presumably from hefty RoundUp use over 30 years.
Although not everyone agrees on the level of damage the long-term use of herbicides can cause, the evidence is surely something to consider when deciding whether to use them or not and how much.
Simple and Safe Ways to Deal With Crabgrass
If some odd crabgrass growth does appear on your lawn, there are other ways to treat it besides using synthetic herbicides. When used properly, natural herbicides and weed remedies are safe and don’t harm the environment.
“Enough with all the talking! Let’s get to the bottom of it!” – I hear some of you in my virtual audience shout.
Due to popular demand, let’s explore the best options for killing crabgrass naturally right away.
How To Combat Crabgrass Naturally
First of all, you should know that there are two paths to take when dealing with crabgrass or any other weed for that matter. Those are prevention and removal.
As the years go by, you will likely find yourself in the need to use methods from both categories (even the best lawns can get an odd crabgrass infestation or some individual cases), so I suggest that you don’t skip chapters.
As with all other aspects of life, prevention is more efficient than the cure, so I won’t spare any words of advice on how to prevent crabgrass from taking over – on appearing at all
Maintaining a Lush, Healthy Lawn
The key way to sabotage crabgrass is to maintain a thick, uniform lawn. The lawn should be healthy, with turf in good condition since crabgrass can easily overpower weak turf. Also, there should be no ruts or bald spots, because it is precisely here that crabgrass likes to take root.
Easier said than done, right? It’s not enough to just wish for a healthy lawn to make it happen (sorry, The Gift fans).
Let’s discover a couple of tricks that will ensure you get and keep a healthy lawn.
Set your mower deck high! Most lawns are cut too low – in fact, that is officially the number one mowing mistake. The golden rule is to cut only ⅓ of the grass blade each time you mow. Giving the ideal mowing height for maintaining a thick turf being between 2 and 3.75 inches.
Plus, constant surface wetness creates an ideal ground for the occurrence of turf disease.
Seeding and Sodding the Bald Spots
As I’ve mentioned, crabgrass and other weed seeds love to nest and sprout in the bald patches of your lawn. It’s their gateway for moving in. That is why it pays off to seed or sod those patches ASAP.
When you remove crabgrass by any of the given methods, also make sure you mend the newly created baldness by sowing of seed, preceded by appropriate fertilizing.
Apply the Natural Pre-Emergent
The role of a pre-emergent agent is to stop any seeds from germinating. Since crabgrass produces so many seeds and since that is the main tactic it uses to spread around, applying the pre-emergent over your grass in the spring is well worth it.
Corn gluten is a great organic pre-emergent that will hinder crabgrass seed germination. Also, as it degrades, it releases nitrogen that feeds your already established turf.
Apply 20 pounds of corn gluten for every 1,000 square feet of your lawn.
Killing Crabgrass Naturally
Naturally, as crabgrass is so omnipresent, it will eventually appear somewhere on your property. If you discover it and get rid of it in time, it is highly unlikely it will cause an infestation. However, even if crabgrass has started to run wild on your property, there are still ways to get rid of it.
I have to admit that I’m not a fan of weed pulling. My knees ache whenever I crouch or crawl and it is, to put it honestly, tedious work.
But you know what? Sometimes the good ole’ weeding is the simplest and the most straightforward thing to do.
The good news about crabgrass is that it has shallow roots, so it’s not hard to pull or dig out completely. Additionally, it has no rhizomes that would sprout again if you happen to leave any roots behind. So in the case of crabgrass, pulling it out is worth the time and discomfort.
Of course, any discomfort will be lessened if you find and pull your crabgrass early, in the spring, when the new grass is still small enough to handle with ease.
Still, even if you discover crabgrass later in the summer when the plant’s root system is already strong, there are special weeding tools (link to Walmart.com) to make the job easier both on you and your lawn since precise pulling creates less damage to the turf that surrounds the weed.
Since crabgrass has… well, crab-like roots which spread a lot, it would be best to use a claw weeder. Alternatively, you can try to use a pitchfork.
Here is a short instruction on how to pull out the crabgrass or other similar weeds:
- First, water your lawn for a while to soften and loosen the soil.
- Uproot the crabgrass by using your hand or a weeder of your choosing.
- Put the crabgrass in a bag (especially important if it is already seeding).
- Add the appropriate rooting fertilizer to the now-bare area.
- Reseed the spot with your standard favorite turfgrass variety.
However, there are simply times when there is too much crabgrass to be pulled out one by one. That is when you can move to Plan B.
Or Plan C, or D.
We have plenty of natural crabgrass-killing plans for you.
Killing Crabgrass With Baking Soda
Common baking soda acts as a contact herbicide, chemically destroying plant leaves over a few days.
Simply apply baking soda on the moist crabgrass patch and wait.
You will need to make the grass wet so the powder could stick to the grass blades. Remember, this is a contact herbicide, so no contact equals no weed killing.
The crabgrass blades will start turning brown and black, and in a few days, you will have yourself some dead crabgrass. You can repeat the process if needed. For best results, uproot it and seed or sod the new grass as soon as possible.
Caution: Baking soda acts as a general herbicide, meaning it will damage all plant leaves it comes into contact with. Be careful not to spread it over the turfgrass.
Killing Crabgrass With Vinegar
Vinegar will dissolve the cell walls of the plant you spray with it, effectively killing it. Unfortunately, you can’t use your regular kitchen vinegar, as the vinegar’s strength needs to be at least 20% for it to be efficient against weeds.
On the bright side, specialized products are available – you can buy industrial-strength vinegar in the form of organic herbicide. This vinegar’s strength is 30% which makes it ideal even for tough weeds.
The only drawback of using vinegar products is, expectedly, the strong smell of vinegar – but it will go away quicker than you may think at first.
As with baking soda, be careful not to apply the vinegar-based solutions to other desirable plants.
Sun-Baking the Crabgrass
Although crabgrass is a warmth-loving plant, there is only so much heat it can take. Solarizing is a simple technique where you use airtight plastic wrapping to basically cook the weed trapped underneath it.
Not only that this process will kill the mature weeds, but it will also kill the seeds, which makes the method ideal for large, mature, seeding crabgrass patches.
Because of that, solarizing is superior to the typical black plastic cover method (see the vid at the end of the article) which deprives plants of sunlight, eventually killing them – but not the long-viable seeds too.
Unlike manual removal, solarization enables you to get rid of entire patches at once (you just have to wait a while). The best thing about this method is that you can get rid of very large patches of crabgrass with a one-time effort (plus some waiting). The downside is that solarizing affects all plants – so all the turfgrass that ends up trapped underneath the plastic wrap will die too.
Here is how to solarize the pesky crab weed:
- Wait for really sunny and warm weather – late spring and summer are the best times for solarizing, but you can also do it earlier.
- Cut the crabgrass with your mower as short as possible.
- Water the crabgrass area (and don’t save).
- Take an unpunctured, whole piece of plastic sheet and cover the crabgrass area.
- Leave it that way between a month and a month and a half.
Burning the Crabgrass
It may sound a bit over-the-top, but killing it with fire actually does apply to weeds – crabgrass included. Torching weeds with a specialized weed burner or torch is a natural, chemical-free, and quite a theatrical way to destroy crabgrass.
There is no need to reduce the crabgrass to ashes. All you have to do is expose it to the flame for a few seconds, and that will be enough to kill the plant by fatally damaging its cell structure.
Weed burner is suitable for individual plants and incidental appearings of crabgrass, but trying to burn large patches of weeds would be impractical and not so efficient.
Although some sources will recommend using a heat gun or a blow torch, I recommend sticking to the specialized weed burners. These torches are easy to control, they are designed for use on weeds, and are quite safe – as long as you’re following the safety guidelines and you are using the protection equipment.
I hope this article has helped you to find out how to get rid of crabgrass naturally, and that now you feel empowered to deal with it. You can choose between many weapons and approaches.
Before reaching for synthetic weed killers which may damage your health and the environment, why not try these natural options and see if they work.
And do they truly work? Please share your experience with killing weeds naturally in the comments and help the knowledge spread.