Nitrogen and other nutrients should be added, as needed per soil testing results, to the soil before planting tomatoes. Too much nitrogen can lead to big, giant plants with no fruit. A soil test through your local cooperative extension office will show you the amount of nitrogen that needs to be added for healthy growth.
About this Author
Bobbi Keffer attended Kent State University, studying education but soon found her true love to be in the garden. She prides herself on her frugal skills, re-using, recycling, and re-inventing her whimsical style in her home and garden.