When do I apply corn gluten to prevent crabgrass?
Last year with your help, I had a beautiful lawn in spring and into the summer months. Then around August the lawn started dying in certain locations, large areas. I did not know what was causing this, so i sent you's an email explaining the problem and the dianosis was grubs. So this past weekend I started raking up much of the dead carpet-like grass. I ran a mantis tiller with aerating blades and loosened up the soil. I broadcasted pennington pa state mix grass seed with jonathan green mag-i-cal and Scotts starter fertilizer which are the same products I started with last year. Now i would like your help on the application of corn gluten to prevent crabgrass and if i can apply in time before they appear. Thank you!
Philadelphia County Pennsylvania
Unfortunately corn gluten works the same way as other pre emergent herbicides by inhibiting the growth of all seeds. Thus the application of corn gluten at this time could negate all the work you have done with your recent seeding. My recommendation would be to continue to build a strong, thick turf through the balance of the year and attempt spot control of any crab grass that appears during the summer to reduce self seeding of crab grass. Fall is typically the best time to reseed or over seed which you might consider later this year to continue to build a strong, thick turf and crowd out weeds. Next spring you can apply corn gluten to prevent crabgrass and other annual weeds. Please note that timing of the corn gluten is critical. The ground temperature needs to be 55-58 degrees in the top one inch of soil for 4-5 consecutive days. This typically occurs between mid March and Mid April in your area. The application then needs to be watered in and then you need a couple of days of dry weather to prevent the crab grass and other weeds from establishing a root system. You may need to repeat the corn gluten application for a few years to increase its effectiveness. Good luck with your effort.