Lawn damage

Asked April 9, 2020, 4:34 PM EDT

For several years now I have had spots of bleached looking grass in the front half of my yard. Last year I had the soil tested at Univ of Del and applied the fall fertilizer they recommended. But the lawn looks the same. I have not seen any mounds of dirt or underground tunnels to suggest its moles. The property is locate in northern Balto Co, just 1/4 mile south of Pa.,. See photos below which were taken a few days ago. Any ideas? Much appreciated? Thx

Baltimore County Maryland

1 Response

Your close-up photo shows two problem weeds: chickweed and nimblewill. These are two very different weeds. The overall site photo (3rd photo), however, may hold the most important clue to why these are becoming a problem.

That part of your lawn looks significantly lower. We had abnormally high rainfall in 2018 through early 2019. Many plants drown, including grass. Grass cannot sit in saturated or flooded soils. The roots die (from lack of oxygen.) If this area was too wet for too long, that may have killed a lot of the grass and opened up the soil for weeds to move into the bare areas or thin areas.

Since it is unlikely that we will have another rain event like that anytime soon (though with climate change, all bets are off), the easiest solution is to thicken up the lawn there again. The best time is late summer-early fall. Use a plug aerating machine, if possible (you can rent them) to make many, many holes, then seed. Here is our page on renovating a lawn: https://extension.umd.edu/hgic/topics/lawn-renovation-and-overseeding You can do a soil test now to get the soil ready for fall seeding.

One weed you have is nimblewill, which is a perennial. It's the one that looks like dead grass in the winter, but greens up in the summer. Here's more:
https://extension.umd.edu/hgic/topics/nimblewill

The weed with small oval leaves is chickweed, an annual that will die soon: https://extension.umd.edu/hgic/topics/common-chickweed

The chickweed is easy to eliminate by thickening up your turf.

Ellen