Are you struggling to grow a vibrant and lush St Augustine property? Relax, you’re not alone! Many gardeners and homeowners face challenges fighting the war against weeds in their lawns. One of the most common weeds that cause significant problems in yards is crabgrass. If you’re struggling with this weed and looking for a crabgrass killer for St Augustine grass, here are the best three options.
The best crabgrass killers for St Augustine grass lawns are grouped into three categories: homemade, natural, and chemical crabgrass killers. The homemade crabgrass remedies are inexpensive, but you must apply the products multiple times for maximum effectiveness. You can also use the natural product, which kills the crabgrass without harming your St Augustine. The commercial chemicals will also help eliminate crabgrass but might damage your St Augustine lawn.
Best Crabgrass Killer for St Augustine Grass

Option 1. Chemical Crabgrass Killer
Various commercial products are available that help kill crabgrass in St Augustine grass. Most of these chemicals are selective in the weed types and grasses they eliminate. This allows homeowners to get rid of crabgrass and other weeds without damaging lawns. They include the following:
i. MSMA Crabgrass Killer: This commercial weed killer is restricted to crabgrass, Bahia grass, quack grass, dallis grass, and Johnson grass. Before you purchase the chemical for your St Augustine lawn, read the instructions carefully. Some are labelled “Do NOT use this crabgrass killer for St Augustine grass”.
Several reviews show that MSMA was once the best chemical control for crabgrass in St Augustine. However, the product is no longer available in the market due to environmental concerns.
ii. Quinclorac Crabgrass Killer: The most effective post emergent crabgrass killer for St Augustine grass contains Quinclorac as the active ingredient. However, you must use the chemical cautiously to avoid killing your lawn.
iii. Atrazine Weed Killer: Atrazine is another product widely used in the United States to help suppress crabgrass in your St Augustine grass. However, it has possible harmful effects on the environment and people.
Option 2. Homemade Crabgrass Killer
For homeowners who prefer homemade crabgrass remedies, there are various solutions available. They include vinegar, baking soda, and boiling water. Baking soda has phytotoxic effects, making it an effective crabgrass killer. For spot treatment, mix two parts of vinegar and one part of baking soda, then apply to the target weeds. Use these remedies carefully and sparingly, as they may also be detrimental to grass.
Option 3. Natural Crabgrass Killer
If you’re looking for the most environmentally and health-friendly product for your St Augustine, go for AgraLawn Crab Grass Killer. The powder contains natural ingredients like baking soda, cumin, corn flour, and wheat flour. It kills the weed to the root effectively and is safe for your lawn, provided you follow the label directions carefully
What is the best herbicide for St Augustine grass?
The most recommended crabgrass killer for St Augustine lawn is Nitro-Phos 15-5-10 with Atrazine. However, do not repeatedly use a product with Atrazine to avoid damaging your property. If you need weed and feed for your grass, apply Nitro-Phos 15-5-10 with Trimec.
What will kill crabgrass but not St Augustine?
Agralawn Crabgrass Killer and Blindside Herbicide WDG (pictured above) effectively eliminate stubborn crabgrass and many other weeds. The products are safe to be used on St Augustine provided you follow the application procedure.
Final Thoughts
Worry no more if you’re struggling with crabgrass in your St Augustine property! You can use the above options to eradicate this pesky weed and many others from your lawn.
These crabgrass killer options include chemical, natural, and homemade weed control methods. Following the application instructions carefully will finally help you achieve a vigorous, well-manicured St Augustine lawn.
