How to control worm populations?

[enantiomer2000]

I live in a townhouse with a private yard that is completely enclosed with concrete. On both sides of the private yard are planters built into the concrete. My problem is that whenever it rains, hundreds of worms come up out of the soil and throw themselves onto the concrete floor where they die. I find myself having to scrape them off the ground quite often in the rainy season. The planters do have drainage, but I think it may not be enough.

I researched toxins to reduce the worm population, but they seem dangerous. If it was a few (or even a few dozen) worms coming out of the soil, I wouldn't mind so much, but I kid you not there are hundreds.

Any ideas on how to address the situation? Totally new to gardening so please excuse my ignorance.

[rainbowgardener]

The problem isn't really the worms, it's the soil. The fact that you have lots of earthworms in your soil is a good thing. They only come out in the rain because they are drowning, otherwise they would much prefer to stay in their little worm caves. So it sounds like there's not enough drainage, that the water stays in the soil too much when it rains.

If you can work on the drainage, that should take care of the problem. You may need to find a way to divert some of the rainwater away from the area, make some irrigation channels, or just improve the soil if it is too much clay. Sometimes if you have hard clay soil with a layer of good loose soil above it, you get a "bathtub" effect, where the water hits the clay and won't go anywhere and just fills up the soil above it. If that is the case, taking rebar or something and poking some holes down into the clay should help.

[dirtyfingers]

Have any fishing buddies?