Begin by incorporating a lot of compost into the soil, as well as 2 to 3 pounds of a complete fertilizer, such as 15-5-10, per 100 square feet. Ft. Use an organic fertilizer such as blood meal, well-rotted manure, cottonseed meal, or bat guano if you prefer. Burpee’s Big Boy Tomato Food works well with eggplants as well.