What kind of fertilizer should I use for yellowing leaves?

Question

My basil leaves are fading in color and I think they need fertilizer. We’ve had a lot of rain recently
and I think all the good stuff has leached out. Should I use epsom salts for plants diluted in water (for nitrogen), cow manure, crushed eggshells (for calcium) or a slow-release granular fertilizer like Osmocote?

Answer 1

We don't recommend certain brands, but a general, all-purpose slow release fertilizer works well. You can also use fish emulsion or diluted water-soluble fertilizer.

Here is more:
https://www.gardeningknowhow.com/edible/herbs/basil/fertilizing-basil-plants.htm