Calendula, although often called pot marigold, is an entirely different plant. Both the leaves and blooms of this plant are edible and taste delicious in salads. When planted in between tomato plants, calendula is an effective natural way to control pests that feast on tomato plants. These pretty flowers also look sweet in a salad.
Carrots and tomatoes share space well. You can plant carrots when tomatoes are small and they will be ready to harvest by the time that the tomatoes are getting larger and needing more room. If you are short on space, this is a great way to increase your yield.