I grow zinnias every year in my Northern Virginia garden. Zinnias are probably one of the easiest flowers to grow from seed in this area. These warm season annuals can be sown directly into a container or on the ground after the last frost. They need full sun, good air circulation, and they are not particular about the soil. The flowers attract butterflies and bees; deer do not bother the plants.
The only hitch is that some species are prone to powdery mildew. Our hot and humid summer is an ideal environment for this fungal disease that creates a white coating on the plants. It does not kill the plants but makes the foliage unsightly. However, there are some zinnias that are resistant to powdery mildew.
Narrow-leaf zinnia, Zinnia angustifolia or Z. linearis, is a foot tall, bushy plant with narrow leaves and small, single, daisy-like flowers. The flowers are about an inch wide with single-colored petals such as orange, red, pink, white, or yellow. Because of its compact size, it makes an excellent window box or container plant and can be used in the garden as a border plant. These are small but you cut a bunch and put in a small vase.
Mexican zinnia (Z. haageana) is like narrow-leaf zinnia in shape, size, and foliage. The flowers are a little larger and can be single, semi-double, or double petals. Each flower has more than one color – usually a spectrum of sunset colors: red, orange, burgundy, yellow, and cream. I discovered them when I purchased Renee’s Garden Persian Carpet mix, which I love. There are other flower blends such as Aztec Sunset, Jazzy Mix, Old Mexico, and Soleado. Again, small flowers but a bunch can be cut for small vases. These are excellent for containers and as border plants.
There are two series of zinnias that have been bred specifically for powdery mildew resistance: Z. marylandica, also called Zahara, and the Profusion series. Zahara has flowers that are larger than the two previously mentioned species, about 2 to 2 1/2 inches wide. There is a wider flower color range too. The plants are taller, about 18 inches high, which is better for floral arrangements. Profusion is pretty much the same as Zahara, a taller zinnia with larger flowers. Zahara and Profusion give you a wide range of colors to pick from, these are easy to find in seed catalogs.
All of these are going to be easier to find if you look for the seed instead of a plant in a garden center. The companies below have these varieties and here is a list of more than 100 seed companies if you want to look for more zinnias.
Johnny’s Selected Seeds
Kitchen Garden Seeds