Zinnias are part of the aster family. Which actually surprised me as you can find wild aster growing in abundance in fields, ditches and along old railway lines. They withstand hot summer temperatures (and cold apparently too). They are grown in fertile, well drained soil in an area with full sun but as long as they have sufficient water will grow in soil that is poor quality as well. They will reseed themselves each year if you allow them too. You can also harvest the seeds in the fall and use them to plant in the Spring.
Zinnias attract and benefit pollinators. They are pollinated by insects, typically bees and butterflies. Their bright colors draw pollinators to a garden which makes sense seeing all the bees that were buzzing around the flower patch! Monarch butterflies, in particular, love zinnias and pollinate them and use them for food and egg-laying habitat. A wonderful plant to go beside milkweed for our at risk Monarchs.
By planting Zinnias in your veggie garden you deter cucumber beetles and tomato worms. They attract hummingbirds, which eat whiteflies before those flies can damage tomatoes, cucumbers and potatoes. An all around fabulous plant! So make sure you plant some seeds next Spring!