What steps do I take to revitalize a dethatched lawn with a moss infestation?

Asked May 25, 2017, 5:24 PM EDT

I just dethatched a lawn with a moss infestation. The lawn has plenty of sunlight and drains well. I still have a lot of moss. In what order do I reseed, lime and fertilize? How much lime should I use? Is there an all-in-one product that will provide enough lime for the soil pH, iron to kill off the moss, and nutrients for the grass?

Clackamas County Oregon lawns and turf moss in lawn horticulture

1 Response

Thanks for consulting Ask An Expert on your home lawn question. I’m sorry to say there is not a “one-and-done” for your situation. But, a couple of weekends should do it.

What you are doing is lawn renovation. There are several approaches, and, by doing the dethatching, you are about halfway there already.

At this point, I would start with killing the moss. This can be done with an iron-containing product from your local nursery or garden center. Once the moss is dead (it will turn black), rake it out.

Now, I refer you to the Oregon State University publication, Practical Lawn Establishment and Renovation.” The part on renovation begins on page 16, and states:

“Apply seed and fertilizer as you would for a new lawn, and mulch the seeded area lightly with peat moss, sawdust, compost, or other material. Once seeded, treat the lawn just as you would a newly seeded lawn.”

You can apply lime at the same time as fertilizer, if the fertilizer does not contain urea (see back of product label). Without a pH test, it is difficult to recommend an amount to apply, but five pounds per 1,000 square feet would be a reasonable amount.

We are getting close to the end of the window for putting down lawn seed, so don’t delay.

Another publication that might interest you is “Practical Lawn Care for Western Oregon.”

Enjoy your lawn this summer.