Poa Annua control

Asked August 1, 2019, 2:11 PM EDT

I've heard that using a pre-emergent product like Halts is the best way to keep next year's crop from germinating - and that applying it August 1 and again on October 1 is the appropriate timing. Note that I do not use a pre-emergent in the spring because I don't have a problem with Crabgrass and want to be able to put down new grass seed. 1) Is the application of a pre-emergent product Aug. 1 and Oct. 1 the right approach? 2) I assume that raking leaves could destroy the pre-emergent barrier. Would frequently blowing the leaves off have the same negative effect?

Kent County Michigan

3 Responses

A publication from Purdue suggests using pre-emergent herbicide twice a year to control Poa annua. Once in Early September and in the early spring around Late March. I would think it is best to mow leaves into turf or bag them instead of raking to prevent digging into the soil and destroying the herbicide barrier. Raking in late October should not be a problem. See the following article: https://www.extension.purdue.edu/extmedia/ay/ay-41-w.pdf

Thank you for the response. One of the key points of my question was: I understand that raking will disturb the pre-emergent barrier but will repeatedly using a leaf blower do the same thing?

I would not think so it should not disturb the soil. Good question.