Many of us who still have lawns want them chemical-free. We also want them to be weed-free, especially without crabgrass, one of the annual lawn spoilers that can take over a patchy lawn. We are right now in an important window of opportunity for using an organic treatment, corn gluten meal as a lawn weed suppressant. Corn gluten meal inhibits the roots of emerging weeds, crabgrass, plantain, and dandelions* by drying them out. Timing is important. To use corn gluten as organic weed control, you need to do it very soon: at forsythia bloom time, which is around the next week or so. This information from SafeLawns.org is helpful on how to use corn gluten:
The majority of weed seeds — especially the dreaded crabgrass seeds — germinate during a very short window in late winter and early spring depending on the climate. The general rule of thumb is to apply the corn gluten just as the forsythia plants break into bloom in the North.
Pre-emergent is an important part of the equation: it must be done when weed plants are barely there. Getting the corn gluten on too late will actually help weeds with developed leaves and good roots, by fertilizing them. So you need to find that perfect Goldilocks time. Look to the forsythia, and apply liberally.
Remember that if you want to keep your lawn and garden organic, hand pulling is always best and will always be part of lawn maintenance, especially on existing weeds. Whether or not your timing is right, corn gluten meal does provide organic nitrogen, so it will help your grass no matter what.
*Personally, I don’t mind dandelions in the lawn. They offer benefits to pollinators as one of the first blooming flowers.