I’m suspicious of organic weed killers. It seems to me that they are either very ineffective, or actually pretty toxic. (Vinegar at high conversations is nasty stuff.)

I saw this organic weed killer, and just ignored it at first. Someone else later recommended it, so I went ahead and bought the recipe and gave it a go.

Two hours later, here were my weeds. The brown is were I applied the weed killer. I was surprised at how quickly it work.

The weeds continued to turn brown and die back. Here’s my thoughts on what I think is going on. This suffocates the plants, plugging up the stomata, preventing the plant from transpiring or getting air. It worked better when the plants were in full sun.

There are limitations to this: it had to be applied pretty thickly to be effective, and just isn’t practical for large areas. It also works as a contact herbicides, so it isn’t going down into the roots like a traditional systemic herbicides like roundup. The bindweed it “killed” grew back in a couple weeks.

I think I mostly prefer chickens, cover cropping, sheet mulching and hand wedding to this method, but it has its place.