I thought it was a great idea—use the old carpet pad we were taking out of our "new" house to smother weeds. I thought the half inch of foam would keep out light and air, and I counted on its soaking up rain and snow and becoming too heavy to blow around. I spread it out and put rocks and pavers on the corners.

Lessons learned

1. Carpet pad does not get heavy with moisture and stay in place. The wind will lift it and move it.



2. Weeds grow better underneath the carpet pad.

In this picture, I'm lifting the carpet pad. The bright green tansymustard seedlings were underneath it; the dark green seedlings just to the right were not covered and were exposed to the cold.

I'm guessing the moisture goes right through along with air and enough light. While letting the necessities of life come through, the pad apparently provides a warm and cozy place to germinate and thrive.

I should leave some padding in place to see if the seedlings grow tall enough to push it off.





Using leaves as mulch
You'd think I'd have learned this by now, but leaves blow away.

The tansymustard is doing well here, too. I had piled leaves around this tree and had even tried to be sure they were moist enough to stay in place.

Plan B

I discovered something that gave me an idea.

It's kind of hard to tell in this photo, but when I pulled back the carpet pad here I didn't see many seedlings underneath it. I think it's because of the leaves that were trapped under the pad.

So—the pad traps the leaves in place. Rain and snow come through the pad and wet the leaves. The wet leaves weighted down by the pad smother the seedlings.

Next I am going to try spreading leaves and weighing them down with carpet pads (weighed down with more rocks, pavers, and anything other heavy item that's handy). I might have to wait until next fall to try that.

Serendipity

When I saw the lush green seedlings under the carpet pads, I thought it was unfair because I have such horrible luck when I deliberately plant seeds. But if the carpet pad works so well with weed seeds, shouldn't it work as well with flower and vegetable seeds? I'll be trying it this year.