Reseeding a lawn filled with crabgrass

Asked September 16, 2017, 9:42 AM EDT

Both front and back lawns (under 2,000 square feet) are a mix of fescue, rye, and wonderful crabgrass). I'd like to start over but I've read about several different re-seeding methods. I've tried thatching and overseeing and top dressing the bare areas with Scotts lawn soil. That did (and didn't) work. I'm tempted to spray and kill the whole lawn (thus getting rid of the crabgrass) to start all over (it's an old, nature lawn). What's the best approach? By the way I used Scotts Northwest seed variety which has encapsulated fertilizer and in most areas it germinated last fall). Ant suggestions would be helpful even for future reference!

Washington County Oregon

1 Response

Thanks for your questions about your lawn. I say "questions" because it's a combination of "out with the old" and "in with the new!" The answer to the first has 2 options: the organic method and the chemical method, both of which are explained here. Of course, since you have such a large lot, you might want to use one approach in one place and the other in the other space.

Although the thought of black plastic covering all or some of your lawn space might seem unattractive, you can also cover it with sheets of cardboard, and hold it down over the winter. (Some people ditch the plastic, and go straight for the cardboard.) One of the disadvantages of plastic is that it prevents water and air from reaching the soil underneath, and important microbes might not be able to survive the winter, which makes your soil less healthy when you remove it.

The second part is covered very thoroughly in this Extension article, which has a link in the first one. I think you've probably missed the 'sweet time' in the fall to re-seed, especially since it's going to take you a few days (or weeks) to get rid of what you have (unless you hire it done ASAP). And leaving bare soil through the winter is hard on the soil, since the winter rains compress it and drive out air. So, you might want to concentrate on getting rid of the old now, covering the space, and wait for reseeding in early May.

Hope these are helpful to you. Good luck!