We recommend these organic fertilizers:
Blood meal or fish meal for nitrogen
Bone meal or bat guano for phosphorus
Wood ash or kelp meal for potassium
Dolomite lime for calcium and magnesium
Epsom salts for magnesium and sulfur
There are also commercially available soil blends that already contain the proper mix of these types of ingredients.
For first-time growers, we recommend avoiding commercial fertilizers like long-release granular fertilizers. These can be used, but you need to have a good understanding of how they work and what your plants need.
We also advise against using nutrients designed for indoor weed growing—they are generally composed of synthetic mineral salts and can damage soil bacteria.