Crabgrass is a pesky annual weed that needs to be prevented early in the season. There are a number of crabgrass killers on the market, but applying a split application of pre-emergent herbicides as part of your early spring lawn care steps and late spring/early summer can limit the need for any post-emergent herbicides. That’s why controlling crabgrass is one of the first things we cool-season lawn care nuts do to establish a healthy lawn.
Crabgrass seeds germinate when the soil temperatures reach approximately 55 degrees for three consecutive days. A good rule of thumb is when you see the forsythia in bloom, the crabgrass is germinating. Without proper pre-emergent herbicides, crabgrass will continue to grow throughout the spring and early summer months as the ground temps approach 70 degrees. Know precisely when to apply a crabgrass preventer.
The best mode of action is applying a crabgrass preventer application in early spring (e.g. Prodiamine in early April in New England) and a second pre-emergent weed control application in early June. Crabgrass pre-emergent herbicides form a vapor barrier in the soil that inhibits the crabgrass rooting from taking place and prevents the crabgrass seedlings from growing and emerging.
I’ve treated hundreds of acres of lawns using many different pre-emergents. Below is my list of top-tested herbicides for crabgrass-free lawns.
Prodiamine is the king of crabgrass prevention. This 50 lbs. bag of 0-0-7 Prodiamine 0.37% will cover 12,500 sq. ft. at 4 lbs. per 1,000. This does not contain any fertilizer other than 7% Potassium, which is mainly used as a carrier.
Apply this best crabgrass pre-emergent herbicide in the early spring as soil temperatures approach 50 degrees. Water this in with 1/2″ of water immediately for best results. I’ve been using this for three seasons now with awesome results. In fact, my lawn was crabgrass-free all season long with a single application that I applied in early April. I personally don’t apply a crabgrass preventer with fertilizer (N-P-K) this early because the turf isn’t quite ready to be pushed, especially if you prepared your lawn for winter and applied a winter fertilizer app. However, they’re a great choice for your second or third split application (more below).
Please note that there is a maximum annual rate of Prodiamine per calendar year. So if you plan on using this in early April to prevent crabgrass and in the fall to control poa annua, keep this chart handy (cool-season grasses listed only):
|GRASS TYPES||LBS./ 1,000 SQ. FT PER YEAR|
|Tall Fescue||9.3 lbs./1,000 sq. ft|
|Creeping Red Fescue||4.6 lbs.|
|Creeping Bentgrass||40. lbs.|
For around $59 shipped, this 50# bag of crabgrass preventer is an awesome deal.
Lawn Phix Review: Prodiamine 0-0-7 has been an integral part of my crabgrass prevention program for years. It spreads easily in any fertilizer spreader (I use a Spyker 50#) and works awesome as a Round 1 prevention. We saw no noticeable crabgrass growth in the years of using 0-0-7 – even along the hotspot areas of my sidewalks and driveways.
For a second split application of crabgrass pre-emergent herbicides, a fertilizer-herbicide combo has been on my calendar – and The Andersons 21-0-10 with 0.25% Dimension is a great choice. About 8 weeks after your first Prodiamine application is when your second herbicide application can be applied. At this time, the soil temps are warmer and the grass is growing like crazy. The best time to apply this in New England would be in early June.
The 21% nitrogen is all urea, which means you will get a very fast release and quick “pop”, and the 10% Soluble Potash (K20) may help with the upcoming summer stress. Secondly, Dimension (Dithiopyr) has post-emergent qualities which can kill younger crabgrass. That’s what makes Dimension a great choice at this time of year.
Andersons Application Rates according to the label:
Use Program 1 for preemergence control at sites where the turfgrass is cut high (e.g., homeowner lawns). This program provides 3-5 months of preemergence crabgrass control. This program should not be used for early postemergence crabgrass control.
Use Program 2 for preemergence control at sites where (a) turfgrass is cut low (e.g., golf fairways) and (b) turfgrass maintenance or weed control has been conducted during the previous year. This program provides 4-6 months of preemergence crabgrass control. This program may also be used for early postemergence control at sites where turfgrass is cut high (e.g., homeowner lawns).
Use Program 3 for preemergence control at sites where (a) turfgrass is cut low (e.g., golf fairways), and (b) turf maintenance or weed control has not been conducted during the previous year. This program provides 4-6 months of preemergence crabgrass control. This program may also be used for early postemergence control at sites where turfgrass is cut low (e.g., golf fairways)
|PROGRAM||Program 1||Program 2||Program 3|
|Northern||1.2 lbs.||1.7 lbs.||2.3 lbs.|
|Transitional||1.7 lbs.||2.3 lbs.||3.4 lbs.|
|South||2.3 lbs.||3.4 lbs.||4.6 lbs.|
|Coastal South||3.4 lbs.||4.6 lbs.||4.6 lbs.|
Lawn Phix Review: I am a big fan of Andersons. The homogenous blend spreads nicely through a broadcast spreader ensures even coverage. Following up 2-3 months after my 0-0-7 application provided full-season coverage. The 21% nitrogen also provided a timely feeding and nice green-up, while the 10% potassium helps with the stresses of summer months. I saw no crabgrass breakthrough. It also did not interfere with my overseeding in September.
Dimension 2EW is a great liquid option as it provides excellent pre-emergent control of crabgrass. This product can also control other annual grassy weeds such as Poa Annua, Dallisgrass, and Goosegrass, and even broadleaf weeds like Chickweed, Purslane, and Spurge. And like The Andersons with Dimension, 2EW can also kill crabgrass in the early stages.
The application rates for Dimension 2EW 0.28-0.73 oz. per gallon per 1,000 sq. ft. Do not apply more than 0.73 oz. f Dimension 2EW per 1,000 sq. ft. per application, and no more than 6 pints of Dimension 2EW per acre per year (2.2 fl oz per 1000 sq ft).
The cost for 64 oz. the container comes to $2.28 per ounce ($146 for 1/2 gallon at the time of this published date) which equates to $0.64 – $1.66 per 1,000 sq. ft. After spraying Dimension 2EW herbicide, water in with 1/2″ of irrigation or rainfall within 6 hours of application.
Use our free Dimension Calculator to get your application right.
Lawn Phix Review: This was used on one of my client’s larger lawns (18,000 square feet) and provided great coverage. I saw no visual crabgrass when I used the maximum rates of Dimension 2EW. This is a great product for larger lawns, or those willing to pay a higher upfront price tag for a more long-lasting product. It’s in my rotation for larger lawns and new clients later in the season.
Prodiamine 65WDG is the best option for crabgrass preventers for those on a budget. Quali-Pro is a reputable company that makes highly effective products at a very affordable price. Their products are generic versions of the more expensive brand names – this one being generic Barricade. The “65” refers to the 65% active ingredient, prodiamine; the “WDG” means Wettable Dispersible Granule which is easily mixed and dissolved in water to make a liquid sprayable herbicide.
In addition to controlling large crabgrass and smooth crabgrass, Prodiamine 65WDG is labeled to also control Foxtails, Henbit, Johnsongrass, Woodsorrel, and more.
This 5 lbs. container can cover just over an acre at low rates. Below is a table of the Prodiamine 65WDG application rates for cool-season lawns. You can also use our free Prodiamine Calculator to make sure that you get your application right.
|GRASS-TYPE||OZ. PER ACRE||OZ. PER 1,000 sq. ft||SQ. FT. COVERAGE|
|Tall Fescue||1.0 – 2.3||0.36 – 0.83||22,000 – 9,600|
|0.5 – 1.5||0.185 – 0.55||44,000 – 14,700|
|Fine Fescue||0.5 – 1.15||0.185 – 0.42||44,000 – 19,100|
|Creeping Bentgrass||0.5 – 1.0||0.185 – 0.37||44,000 – 22,000|
Lawn Phix Review: The same Active Ingredient (AI) as the 0-0-7 crabgrass preventer, but in dissolvable and sprayable form. The yellow WDG ‘pellets’ need to be accurately measured on a small scale/yield. I was cognizant to keep shaking the sprayer to keep the chemicals suspended in the tank. I tested this product on a smaller section of our lawn and saw no visible crabgrass throughout the growing season. Overall, a great option for those with a smaller budget, and who don’t mind weighing out the solid product and mixing.
For more options, the same Sunniland 65WDG product is sold on Yard Mastery in a smaller 5 oz. bottle.
To finish of this list of the best crabgrass pre-emergent herbicides and preventers is Pendulum 2G. This herbicide contains an active ingredient Pendimethalin – which is the same chemical that is found in Scott’s Halts (a fine alternative).
For 2-4 months of coverage, apply Pendulum 2G at rates of 2.3 lbs. per 1,000 sq. ft. For longer coverage (6-8 months) apply up to 4.6 lbs. per 1,000 sq. ft. per application. At these rates, a 40 lbs. bag will cover between 8,700 – 17,400 sq. ft. of turfgrass. Pendulum 2G also controls the emergence of both grassy weeds and broadleaf weeds such as Oxalis, Poa Annua, Purslane, and many more.
Lawn Phix Review: Worked as expected on my client’s 8,000 square foot lawn. A good all-around grassy weed preventer. I also applied Pendulum to my side yard – approximately 3,000 square feet – this fall to help prevent Poa Annua outbreak next season.
It is important to know that these crabgrass preventers will affect your grass seeds from germinating, too. Whether you’re overseeding a lawn or filling in some bare spots, applying these products will not just prevent crabgrass and other weeds, but also your good grass, too. Consider using Tenacity (Mesotrione) when spring seeding to help prevent emerging crabgrass. When not seeding, apply these and other crabgrass preventers sooner than later – before crabgrass seeds germinate (55 degrees).
Crabgrass Pre-Emergents on Amazon
Pre-Emergent Herbicide Overview
Prodiamine (Barricade) Pros
- Long lasting – up to 9 months efficacy
- Inexpensive (particularly generic)
- Best to apply early in the season
- Great crabgrass control and other lawn weeds
Prodiamine (Barricade) Cons
- Needs to be watered in quickly
- Will lose a lot of efficacy if not watered in within 14 days
- Not a great broadleaf weed control
- Breaks down with exposed sunlight (photodegradation)
- Note for aeration and overseed: it’s a good to lower your height of cut (HOC) a couple of weeks prior to allow more sunlight to the soil. This will help ensure the pre-emergent is out of the soil
Dithiopyr (Dimension) Pros
- Better than Prodiamine at preventing broadleaf weeds
- Post emergent qualities that can kill younger crabgrass
- Apply later in the season – great option for your second/third of your split application
Dithiopyr (Dimension) Cons
- Root pruner of good grass (KBG, TTTF, PRG)
- Ensure roots are well-established before applying
- More expensive than Prodiamine
- Less efficacy than Prodiamine (3-4 months)
- Takes higher rates to control crabgrass
- Breaks down more so with water and heat
Crabgrass Preventer vs. Crabgrass Killer
I’ve seen other websites recommending the Green Gobbler Weed Killer. Please note that this is not a crabgrass preventer or a grassy weed preventer – it is a liquid crabgrass killer. On top of that, it is non-selective (20% vinegar). This means, while it can act as post-emergent crabgrass killer, it will also eradicate everything else it touches, like your good turfgrass – akin to glyphosate.
Remember: pre-emergents (in this post), are used as a preventative. When a crabgrass preventer is applied at the right time (early spring and early summer), pre-emergent herbicides help prevent crabgrass and other grassy weeds from emerging and growing.
Crabgrass killers attack the established plant and kill it post-emergently. Use these selective herbicides to kill visible crabgrass and other grassy weeds.
Best Crabgrass Preventer Summary
- Best Granular Preventers
- Best Liquid Preventer
- Best Fertilizer Combo
- Best Budget Preventer
Crabgrass Pre-Emergent Herbicides FAQ’s
When should I apply a crabgrass preventer?
The best mode of action to prevent crabgrass is by applying a split application of pre-emergents. The first application of Prodiamine or Pendimethalin should be applied in early spring before soil temperatures reach 55 degrees. The second application should be applied approximately 8 weeks after. In Massachusetts for example, this would be in early April and early June.
How long does crabgrass preventer last?
Depending on the product and application rates, crabgrass pre-emergent herbicides can last between 2-3 months at low rates, to upwards of 8-9 months at maximum rates. It is important to water in these herbicides with 1/2″ of water immediately after applying.
When should I apply Halts crabgrass preventer?
Scott’s Halts contains the active ingredient, Pendimethalin. At max rates, Pendimethalin can last up to 8 months. The best time to apply this pre-emergent in early spring before soil temperatures hit 55 degrees – just as the forsythia bloom.
Can I apply fertilizer with a crabgrass preventer?
Yes. Many pre-emergents also contain fertilizer all-in-one. Many Step 1 fertilizers will contain high rates of Nitrogen and lower Potassium numbers with a crabgrass preventer. If you apply in early spring, you may want to skip the fertilizer until later when the grass begins to actively grow. For applications in late spring and early summer, an all-in-one like 20-0-10 is a great choice.
What are the best crabgrass preventers?
To prevent crabgrass and other grassy weeds, you will want to look for selective herbicides that have the following active ingredients:
* Prodiamine (Barricade)
* Dithiopyr (Dimension)
* Pendimethalin (Pendulum, Halts)