I just planted a rose and used a third of the packet of mycorrhizal fungi that came with it. Now, I'm wondering what to do with the leftover fungi since I don't have plans to plant more roses in the near future. Should I apply it around existing plants, or is it better to store it for later use? I've heard that mycorrhizal fungi have a short lifespan; should I store it or just toss it?
3 Answers
Definitely store it! Just put it in a sealed jar to keep it fresh. Avoid sprinkling it on the surface of existing plants; it's not very effective that way.
From what I've learned, mycorrhizal fungi are best when they're mixed into the soil where new plants or bare roots are going in. So, for your existing plants, it may not really be necessary. I'd recommend saving it for when you eventually plant something else like a bare root. Just keep it stored well for later!
Honestly, if you're not planting anything soon, you could just keep it in an air-tight container. Just don’t go tossing it around on top of the soil—it won’t do much that way!

Yeah, it really works best when it's in direct contact with roots at planting time, so keep that in mind!