Now here is a flower group that has so many colors, so many sizes, so many bloom shapes… there is truly a type of Zinnia for everybody! They are easy to grow from seed, fast-growing, and sun-loving. Zinnias hold a special place in my heart, as they were my grandmother’s signature flower. She had rows upon rows of tall, gorgeous, colorful Zinnias each and every year! Learn how to grow and care for Zinnias right here with our detailed guide.
Table of Contents
Basic Facts
| Common Names | Zinnia |
|---|---|
| Botanical Name | Zinnia elegans; Zinnia angustifolia (shorter variety) |
| Family | Asteraceae |
| Zones | Grown as an annual. Collect the seeds from the dried flower heads, store them over the winter, and plant them in the landscape the next year. |
| Flower Colors | Reds, Oranges, Yellows, Purples, Violets, Pinks, White, Various bi-color varieties |
| Height & Spread | Anywhere from 6″ to 4′ high, depending on variety. |
How to Grow and Care For Zinnia
When to Plant Zinnias?
Zinnias are most often started by seed directly planted in the landscape. Wait until all danger of frost has passed before sowing seeds in the ground. If you are instead planning to buy Zinnia plants from the garden center, wait until late spring to early summer, as Zinnias thrive in warm to hot weather.
What Type of Soil Do Zinnias Like?
Not especially picky about soil type as long as it is well-draining.
Do Zinnias Need Sun or Shade?
Zinnia plants will do best in Full sun.
How Often to Water Zinnias
Although Zinnias are drought-tolerant when established, they should still be watered regularly for best performance. Water at soil level so that you can avoid getting the foliage wet. Many Zinnia varieties are very susceptible to powdery mildew. Watering in the morning is also advisable if possible.
When to Fertilize Zinnia
Zinnias should be fertilized every 4-6 weeks with a balanced fertilizer.
Potential Pests & Diseases
- Powdery mildew (See more in the FAQ section further below)
- Japanese Beetles
Frequently Asked Questions
How Can Powdery Mildew on Zinnias Be Prevented?
Unfortunately Zinnias are very susceptible to powdery mildew from overly wet conditions. There are some ways you can avoid this fate for the foliage of your Zinnia plants, but it might also be somewhat out of your control (if it rains several days in a row, for example). The very best thing you can do is to water your Zinnias from the base of the plant, trying not to get any of the leaves wet. You also need to avoid splashing water from the soil level onto the leaves, as this can transfer fungal problems easily. Lastly, you should water in the morning, so that the sun has a chance to quickly dry off any leaves that may have gotten moisture on them.
Now, while powdery mildew might make your Zinnia plants have unattractive foliage, it isn’t usually a death sentence for the plant itself. If you have Zinnias that grow quite tall, you can also plant some shorter plants in front to help hide the foliage of your Zinnias.