PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchCorn gluten meal (CGM) may suppress some weeds before they emerge, but it is not a reliable weed barrier or a treatment for established weeds. Its results depend on timing and weather, and the amount used for a possible herbicidal effect also adds nitrogen to the soil. Treat it as a conditional option: check the product label, local guidance, and your lawn’s fertilizer needs before applying it.
What corn gluten meal can—and cannot—do
CGM is intended to interfere with root development in newly germinating seedlings. It does not kill established weeds, so it will not clear visible weeds from a lawn or garden. Iowa State Extension describes this pre-emergent use, but reviews from Washington State University and UC IPM report inconsistent results in real-world lawns and gardens. Some research found little or no control of most turf weed species.
CGM is also a nitrogen fertilizer. That nutrient may help turf compete with weeds in some situations, but it can also feed weeds; improved turf growth is not proof that CGM reliably prevents weed emergence.
When to apply it to a lawn
Apply before the target weeds germinate, not after they appear. Iowa State University Extension and Outreach, in guidance reviewed in 2025, gives mid-March to early April as a typical window for its region—about three to five weeks before crabgrass germination. That calendar window is not universal: use local weed-emergence guidance and the product label rather than assuming the same dates fit every climate.
#1 Best Overall
- CONTAINS: Espoma Organic Weed Preventer Plus Lawn Food is made from 100% corn gluten meal. No sludges or fillers.
- USE FOR: Helps prevent weed seed establishment and provides organic nitrogen that keeps lawns a deep green color longer than conventional lawn foods. Prevents Common Weeds like Crabgrass and Dandelions.
- WHEN / HOW TO USE: Use in the early Spring to help prevent crabgrass and other weeds. Apply with a drop or broadcast spreader.
- COVERS: Weed Preventer rate for lawns: 20 lbs. per 1,000 sq. ft. covers up to 1,250 sq. ft. Feeding lawns: 10 lbs. per 1,000 sq. ft. covers up to 2,500 sq. ft.
- MADE IN THE USA: Product of the Espoma Company
University of Illinois Extension describes forsythia bloom or several consecutive days with shallow soil temperatures around 55°F as possible timing cues. These are cues, not guarantees; follow local advice and label directions.
How to apply CGM
- Check the label. Confirm that the exact product permits the intended lawn or garden use. A product sold as CGM fertilizer is not automatically labeled or demonstrated for herbicidal use.
- Check the rate and area. Iowa State Extension’s example lawn rate is 20 pounds of product per 1,000 square feet. Use the label’s directions if they differ, and do not treat this extension example as a universal product rate.
- Distribute it evenly. Iowa State notes that granules are easier to spread than meal. A broadcast spreader can help, although Illinois Extension notes that the high application rate may require multiple passes. No particular spreader has been established as necessary.
- Water lightly, then let the surface dry. Iowa State recommends a light watering followed by a dry period. Extended rainfall or irrigation may reduce effectiveness, so avoid expecting reliable results in persistently wet conditions.
- Keep it away from seed you want to grow. Do not apply where desirable grass is being seeded or overseeded. In gardens, wait until transplants and seedlings are established and follow the product label.
Account for the nitrogen
The commonly cited lawn rate comes with a fertilizer tradeoff. Iowa State Extension describes CGM as containing 10 percent nitrogen by volume; Illinois Extension describes about 10 percent nitrogen by weight and warns that a herbicidal application can provide more nitrogen than a lawn should receive at once. Those descriptions use different bases and should not be combined into a precise nitrogen calculation.
Rank #2
- 15 lb Bag – 5,000 sq. ft.
- Safe to use around children and pets
- Provides gentle feeding and deep greening
- Can be used in flower gardens and in planting beds
Check the product’s guaranteed analysis and account for its nitrogen alongside other fertilizer applications. Follow local fertilizer restrictions and do not apply more nitrogen than your lawn needs or local guidance allows.
How dependable is it?
There is no broadly applicable weed-control percentage or success rate established by the cited extension sources. Iowa State notes that results may not be obvious after one season and that repeated use may improve results in lawns, but that is not a promise of control. Washington State University’s review describes inconsistent garden results and little to no control of most turf weeds in one study; UC IPM likewise characterizes results as inconsistent.
Rank #3
- Corn Gluten Meal - Corn-derived granular material for use in lawns, gardens and established landscape areas as part of a seasonal lawn and garden routine
- Lawn & Garden Use - Granular texture makes corn gluten meal convenient to distribute over larger lawn areas with a spreader or apply by hand to smaller garden and landscape areas
- Naturally Contains Nitrogen - Corn gluten meal naturally contains nitrogen, providing a plant nutrient that can be incorporated into lawn and garden maintenance programs
- Resealable Bag - Convenient packaging closes between applications to help contain unused corn gluten meal and make storage easier in a cool, dry location
- Application & Storage - Follow appropriate application rates for your intended use and growing area, keep the material dry and avoid applying immediately before heavy rainfall
Weather, application timing, target weed, and the risk of feeding weeds all matter. If you need predictable control, do not treat CGM as a guaranteed substitute for a method suited to the specific weed and site.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Consider other suppression methods
For landscape beds, Washington State University identifies coarse arborist wood-chip mulch as an effective weed-suppression approach. For lawns, the sources do not establish one best alternative for every weed; choose an approach based on the target species, site, and local recommendations rather than assuming a single treatment fits all cases.
Quick Recap
Best Value
- NATURAL WEED PREVENTION - Effectively controls broadleaf and grassy weeds like dandelions and crabgrass before they sprout.
- VERSATILE APPLICATION - Safe for use on lawns, vegetable and flower beds, and around trees and shrubs.
- PATENTED WATER-SOLUBLE FORMULA - Delivers fast-acting, long-lasting protection against new weed growth.
- EFFICIENT COVERAGE - Covers more area with less product compared to traditional granular corn gluten-based formulas.
- PLANT-SAFE SOLUTION - Will not burn or harm existing flowers, plants, or shrubs, making it ideal for garden use.
Rank #4
- CONTAINS: Espoma Organic Turf-tone Weed Preventer Plus Lawn Food is made from 100% Corn Gluten Meal. No sludges or toxic ingredients
- USE FOR: Provides organic nitrogen that keeps lawns a deep green color longer than conventional lawn foods. Prevents Common Weeds like Crabgrass and Dandelions
- WHEN / HOW TO USE: Use in the early Spring. Apply with a drop or broadcast spreader.
- COVERS: Weed Preventer Rate for lawns: 20 lbs. per 1,000 sq. ft. covers up to 1,250 sq. ft. Feeding lawns: 10 lbs. per 1,000 sq. ft. covers up to 2,500 sq. ft.
- MADE IN THE USA: Product of the Espoma Company
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
