I suspect they work pretty good, but for me they are way over-priced. I have considered trying to make something equivalent, but haven't figured out a good way to do it. Maybe Global Warming will kick in and give us an extra warm spring with a much earlier last frost date. (grin)

MM

I used them one or two years. They need support from the inside, or they collapse on the plant. They spring leaks in the separate cells. I suppose they worked well, but for my money, I'd rather use plastic jugs with the bottom cut out. The jugs I use every year, while the wall-o-waters are lying dusty on a garage self waiting to be culled.

I've read about 2 liter soda bottles being taped together and used like w-o-w. I haven't tried this and don't know if it works, but it's an idea.