It is what it says - your plant has a chance to going to day 2 instead of day 1. It does work on plant beds but not all the plants may get the growth - it is not a guarantee. I tried it once on mine and all the plants ended up on different growth cycles - it was just a pain. I rather have all the plants ready on the same day - makes it easier than having to check each plant every day. Esp. when you have more than one plant bed.