If you’re looking for a flower that’s both easy to grow and will provide big color in your garden, look no further than zinnias. Zinnias come in a range of mature heights, making them suitable for planting in containers and flowerbeds and for use as a cut flower. You can find a variety in virtually every color of the rainbow except for blue. Because they are so easy to grow and produce such vibrant flowers, zinnia seeds are a great choice when gardening with children.
There are a few different types of zinnias, and some are more common than others. Zinnia elegans is the type most often found in gardens, and range in height from eight inches to four feet. They are available with single, semi-double, and double varieties. Some popular cultivars include the light green ‘Envy,’ the rounded ‘Ruffles,’ and the twelve to fourteen inch ‘Small World.’ Zinnia augustifolia is less commonly found, but is gaining popularity for its heat tolerance and resistance to powdery mildew. Colors are generally white, orange, yellow, or red. Good cultivars include ‘Crystal’ and ‘Swizzle.’ The least commonly found is Zinnia haageana, or Mexican zinnia.
Because zinnias grow so fast, they can be sown directly in the garden, or you can start them indoors four to six weeks before your average last frost for the earliest flower display. For sowing outdoors, wait until all danger of frost has passed, then sow in rows or groups in soil amended with compost. Keep evenly moist. Once leaves have emerged, thin to recommended spacing. To start indoors, fill a container with good quality, pre-moistened soil mix, then either sow in rows or two or three seeds in each pot. Cover with ¼” to ½” of soil and mist or water lightly. Cover with plastic to retain moisture and place in a sunny location or under a grow lamp. Remove plastic cover once seeds have sprouted and keep evenly moist. Transplant once all danger of frost has passed. For flowerbeds, follow recommended spacing instructions; for cut flowers, space them a little closer together to produce longer stems.