Zinnias are annuals, meaning that they go from seed to flower to seed in one growing season, so they will not come back up the following year. Zinnias like to be grown from seed right in the garden bed – but the seeds can also be started indoors 4-6 weeks before you’re ready to plant them outside. Transplant them while they are young and do so carefully as they don’t like their roots disturbed. They are sensitive to frost, so if direct seeding in the garden do so after the last chance of frost has passed.
Zinnias are really low maintenance. Since they’re fast-growing, they shade out most weeds. They don’t require much in the way of fertilizing (just an occasional well-balanced mix), and they don’t need mulching. Deadheading them helps to produce more flowers. (and who doesn’t love more flowers?) Zinnias grow and flower best in full sun. Water at the base of the plant to avoid powdery mildew from forming on the leaves if they don’t dry out properly. Water early in the day, so the plant has a chance to dry in the warm sun and not sit overnight drenched in water.
One reason to plant zinnias year after year is that they are butterfly magnets. The big flowers act like landing pads for nectar seeking butterflies. (as well as hummingbirds.) Try zinnias with red or hot pink flowers to get the biggest draw.