If you are thinking of companion planting - other heat loving crops like basil are often planted near tomatoes, but this does not increase the yield. Tomatoes need both macro and micro nutrients so I use a complete fertilizer like Osmocote because it contains the calcium and other minerals that tomatoes need for maximum growth as well as the big three nutrients of nitrogen, phosphorous, and potassium. There are also different types of tomato varieties and the more compact or determinate varieties ripen sooner but than stop growing. The spreading and sprawling types called indeterminate will continue to grow until frost and these larger plants have bigger yields. Keep growing, Marianne Binetti