prostrate knotweed and a compacted lawn

Asked June 2, 2017, 9:04 AM EDT

Hello - I have areas of my backyard that are compacted and overrun with weeds. I asked a friend of mine what kind of weed and she figured it is prostrate knotweed. In reading about this weed, it all fits - compacted lawn and growth habit. I read on the UMN extension site that I can manage this weed by aerating and this can be done in the Spring time and again in the Fall. My question - what do I do after I aerate? I would like to take care of this in the next week or so, but am unclear about the procedure. Aerating is easy enough but what steps should I take to make sure the lawn comes back healthy? Also note I am trying to establish a micro-clover lawn. Thanks! Annia

Hennepin County Minnesota

3 Responses

unfortunately, it's going to take more than a week to fix. It is too late to aerate (and spring aeration is not recommended in any case). If there is more weed than grass, it would be best to kill off everything with an herbicide such as Roundup or if you don't want to do that, then covering with heavy black plastic for the rest of the growing season. Aerate in the fall, prepare the area for overseeding and overseed with your clover and grass mixture..

Thanks for your response.

I understand it will take more than a week to fix. I meant aerate in the next week or so. I'm guessing to completely fix this I will need a couple of growing seasons at least.

I do not want to use roundup as I have a dog who eats everything - grass, weeds, etc, so I will cover in black plastic. As for aerating next fall, would it be best to rake up as much of the dead weeds as possible before aerating? And how long should I wait between aerating and over-seeding?

Finally - just curious - why is it not a good idea to aerate in the springtime?

Thanks again -

Aeration in the spring time allows weeds to take root, especially if you don't put a pre-emergent down because you are overseeding.