I'm getting ready to plant some cuttings and also need to transplant a few old house plants that are root-bound. I've been wondering if I should add fertilizer or Mycorrhizal Fungi during the transplant. I read somewhere that it's better to wait three weeks after planting before fertilizing. What do you all think?
5 Answers
It really depends on your soil mix! If it's something like equal parts perlite, orchid bark, and biochar (which has no nutrients), I would fertilize immediately. If you're using standard potting soil, wait about two weeks before feeding. I would suggest using both to give your plants a solid start!
Typically, new potting mixes come with nutrients that last about three months, so I usually skip fertilizing right after I repot. If your mix doesn’t contain Mycorrhizae, then add it in! I personally like using Fox Farms soil as it already has Mycorrhizae and recommends no fertilizer for three months. You could also find some granular Mycorrhizae to dissolve in your watering can for a monthly boost!
I've been reading about adding fungi to planting, and you might consider taking some potting soil from an existing healthy plant. If you've got a good culture, it can spread quickly, and most likely you already have spores in your cuttings. It's interesting how these fungi can travel and help with growth!
Honestly, I'd stick with fertilizer. There's not much evidence showing Mycorrhizal Fungi is really beneficial for potted plants, and the consumer options aren't always reliable. You only need to fertilize a few times a year unless you want super rapid growth!
When you're transplanting, I recommend putting Mycorrhizal Fungi directly on the roots and then watering it in. After that, you can fertilize with the next watering if your soil mix doesn't already have nutrients added. It's a great way to boost the plants right from the start!

That’s a cool idea! It’s amazing how nature works, and using existing potting soil could definitely help with introducing those beneficial microbes.