Corn Gluten Vs Preen To Suppress Weeds

Question From: Attica, Michigan, United States
Q: Nancy- I am going to take you up on your offer to answer questions. I am already making plans for next spring and remember that most of last spring was pulling hairy bitter cress out of my year old ground cover . [There is still a lot of area to fill in with ground covers and it covers a long slope of my back yard]. Hopefully, there will be less of it next spring but to make sure I'd like to put down a pre-emergent herbicide. Is it too late to do any good this fall? I WILL put something down EARLY next spring . I would rather put down corn gluten than Preen if they work equally well and last equally long [I've read Preen last about 3 months. I can't find found information of duration for corn gluten]. Is there another pre-emergent you can recommend? Thank you for sharing your years of experience.

A:
Rita, Here is the answer from my turf pro regarding the use of corn gluten. Use a minimum of 10 pounds per 1000 sq feet. Timing is key 
When the forsythia in your yard or neighborhood are in bloom is a good indicator. 
 Best Nancy and Happy Yardening

 

You will get about 75% control with corn gluten. Repeated use will eventually suppress the weeds in an ornamental setting. Corn gluten should give you about the same length of 75% control as the Preen. I have commercial applicators who have used corn gluten with good success. One advantage of corn gluten is it is also a good long lasting fertilizer and will give your desired plants a good shot of nutrients. It is such a short lived plant with a possible 3 crops per year I would apply a couple of apps 8 weeks apart. Should give your desirables a good slow release fertilizer feeding.