Zinnias are a great trap crop for flea beetles, and they attract pollinators that can improve cucumber pollination.
Watermelons can also use zinnias as a cucumber beetle trap, as long as they're planted a short distance from the flowers.
Dwarf zinnias cover the soil between well pruned tomatoes, improving soil condition and water retention. They'll also attract bees to pollinate tomato flowers!
Marigolds and calendula repel aphids, mites, whiteflies, and they'll both grow well with zinnias. Plant them together for a beautiful veg garden border!
Basil grows in the same conditions as zinnias, and they're both good companions for tomatoes and other fruiting veg. Plant them in full sun, but don't shade out the basil!
for 3 more companion planting ideas + what not to plant with zinnias