Zinnias are annual plants in the Asteraceae family that offer various heights, colors, and types of flowers.
Zinnias are very easy to grow and require little maintenance but offer bright, showy flowers. They attract butterflies and make excellent cut flowers. They are also deer resistant
Plant heights range from 6 inches to several feet tall. Zinnias can be grown in zones 2 through 10. They prefer well-drained, fertile soil and should be grown in full sun.
How to Plant Zinnias
- Plant in soil that is well-drained but fertile and is located in full sun.
- Sow zinnia seeds directly into the soil, after the last frost.
- Cover with ¼ soil
- Keep soil moist until the seeds germinate, in about 4 to 7 days.
- Consider adding compost to loosen and fertilize soil and to help retain moisture.
- Water from below to avoid powdery mildew
Zinnia Spacing & Thinning
Especially in humid areas, zinnias need air to circulate around the base of the plant, so thin seedlings to about 6 to 8 inches apart for shorter varieties and 12-18 inches apart for taller varieties. This can be done when the seedlings are about 3 inches tall. Keep seedlings fairly well watered until they are more mature.
Zinnias are relatively drought-tolerant, but it is a good idea to water them during extremely long dry periods. Watering at the soil level is recommended.
Deadheading
Pinch or cut off dead flowers to encourage bushier growth and more flowers. Do this generally at the base of the next closest leaf branch, being careful not to damage any leaves or buds.
Save Seeds
Zinnias will reseed themselves, but if you’d like to save the seeds to use next year, leave some flowers on the stalk until they appear dry and brown. Cut off the flowers and flake out the seeds into a bag. Generally, the seeds are attached to the base of the petals in zinnias.
Powdery Mildew
In the humid southeast, zinnias are susceptible to powdery mildew, which begins to show up in late summer. If this is a problem where you live, there are some mildew-resistant varieties to try instead of the traditional seeds—additionally, water plants at the ground instead of spraying from above to reduce mildew problems.
Powdery mildew-resistant varieties include
- Zinnia angustifolia
- Zinnia haageana
- Blue Point series
- Pinwheel zinnias
- Profusion zinnias
- Zahara zinnias
Try searching for “mildew resistant zinnias” to find other mildew-resistant varieties.
