These really do work!!! Fill them with water and stick them in your plant pots. The soil releases oxygen as it dries out and this in turn makes the water from the globe come out slowly and gradually over days/weeks. When the globe is empty, its time to refill it, so it's obvious when watering is needed. I've even put liquid plant food mixed with the water in mine so they gradually get fed too. Obviously pushing the tube end into the soil means soil gets into the tube. So a pencil or something similar is needed to dislodge it when refilling the globe. But apart from that, they look nice and do a good job.