PopoMyers
Free Ranging
It does not slow drip. I have 2 of them, and if the soil gets too dry, or is not tamped down in each level, the water goes through the soil quickly. I plug the hole with my finger when filling. Sometimes, I'll put a scoop or two of soluble fertilizer in, then fill. Sometimes, I've had to run water into each level. I have both filled with strawberries.I don't have a Greenstalk but I've read up on them. If I remember correctly you need to dump water into the top quickly, like pouring it out of a bucket. Creates some kind of vortex action I believe.