I'm starting seeds in my basement this week and I'm using a generic seed starting mix for convenience. However, I'm thinking my little seedlings might benefit from some nutrients. What's the best fertilizer specifically for seedlings? I've heard about using seaweed powder, but I'm not sure about brands. Any suggestions? I'll be using Dr. Earth in my raised bed. Thanks a lot for your help!
2 Answers
I've tried a few different fertilizers, and I really like Neptune’s Harvest. Just a heads up though, it has a strong fishy smell, which might be an issue in a closed space like your basement. Last year, I also used Roots Organics, which doesn’t have the fishy scent and worked well for my plants that struggled due to low-quality potting soil. Honestly, starting with a good soil mix is crucial, so if you can get a better one, it might save you from having to rely too much on fertilizer. I also toss in about 1/2 cup of North Country Organics Pro Gro into a five-gallon bucket of soil for my seed flats, and it helps!
I'd wait until your seedlings have their first set of true leaves before fertilizing. Freshly germinated seedlings don’t usually need fertilizer yet, and adding it too soon can do more harm than good.

Thanks for the advice!