Each spike can be used for 30–60 days, depending on the season. The reviewer pics on the right are all of the same plant — the top one shows how this magical stuff helped the rather sad dude perk up in just 10 days, and the bottom one shows that he's completely come back to life three weeks later!

46 Products You'll Wanna Thank For Simply Existing

Promising review:"I always kill my plants but I decided to try again. I just bought five houseplants, and three of them were marked down because they were looking pretty puny. Since I tend to kill them anyway, I figured I would give them a try and save some money.I put one of these spikes in each plant and they all looked so much healthier and happier after just a couple days.I also added one spike to the only houseplant that I've had for years without killing (I was beginning to think it was artificial) the leaves looked healthier almost immediately. I'm very happy with this product and it was a great price." —victoria

Get 24 spikes from Amazon for $2.79.