Updated on June 19, 2024 by Ruth
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Zinnias are a favorite flower for the garden with their cheerful daisy-like flowers and the marvelous variety of colors and sizes. The colorful blooms show off in the garden all summer, attract butterflies and other pollinators, and provide an abundance of flowers for bouquets. Should you grow zinnias yourself? Yes, please! Let’s get started.
Table of Contents
Zinnias are annuals
Zinnias, zinnia elegans, are annual flowers in growing zones 2-11, which covers most of the growing areas we know. Zinnia grandiflora, also known as the plains zinnia” or “Rocky Mountain zinnia” is a perennial hardy in zones 4-9. Zinnia grandiflora is a small, yellow, daisy-like flower, about one-quarter the size of the classic zinnia elegans. We will be discussing zinnia elegans in this article. In their native parts of Mexico and Central America, zinnia elegans are perennials.
Start from seed or buy plants?
The question of starting from seed or buying plants is a question of time. Depending on the specific variety, zinnias take 75-90 days to get to the stage where they start producing flowers. The taller the variety, the longer it takes to grow. Once started, the plants keep producing flowers until the temperatures drop below 40F. The plant will still be alive until a hard frost, but there will be no more flower buds in the cooler temperatures.
You can see that you need enough days to grow the plants so that there are several weeks—preferably months–of enjoying the flowers. You cannot start seeds outside until frost is past, so you are better off starting the seeds indoors and then transplanting the young plants outside as they are big enough and the weather is compatible. If you want zinnias in July, you have to start the seeds in April. In our area, zone 7, it is usually too cold to start seeds outside in April. We always start our zinnia seeds indoors, in our heated high tunnel. As a farm, we have a seed starting area. You may or may not have that available to you.
How to start zinnia seeds
Zinnia seeds germinate fairly quickly, in 3-5 days at 70-75F. Sow the seeds shallowly, with about ¼ inch of soil covering the seeds. The seedlings will be ready to transplant in 14-21 days. Do not let the zinnias become root bound, as they will not transplant as well. Time it so that the weather outside is ready when your seedlings are.
Can you grow zinnias in a pot?
Select the shorter varieties such as Double Zahara for container growing. Allow plenty of space for each plant to grow. Overcrowding in the pot can lead to powdery mildew issues; air flow is your best defense. The dwarf varieties will grow to about 12-20” tall; allow that much space for the width of the plant as well.
What are the best growing conditions for zinnias?
Zinnias are sun-loving plants that can tolerate heat and direct sun. They produce the most flowers when they receive sunshine all day. Fewer sunlight hours results in fewer flowers.
Consistent water is key, and the plants need to dry out in-between watering. Water at the soil level so that the water goes directly to the roots. Watering the leaves or the flowers can result in mildew issues.
Provide compost or other fertilizer when you plant your zinnias. It takes a lot of energy for plants to produce flowers, so nutrients in the soil are key for abundant flowers.
Look for varieties that are resistant to powdery mildew. If you have humid summer weather, that resistance is essential for your plants’ longevity.
When should you cut your flowers?
Cut your zinnias early in the day when it is cooler. The flowers will last longer than if you cut them in the hotter part of the day.
How long will zinnias bloom?
Zinnias will continue to bloom as long as the weather is favorable for them. When the temperatures cool off, the plants stop producing new flowers. Frost will be the end of the zinnias for the year.
Five Fun Facts about Zinnias
- Zinnias repel many pests naturally, making them great to plant near your vegetables.
- Zinnias symbolize endurance and lasting affection.
- Zinnias are completely edible, making them a great garnish for a charcuterie board or dessert.
- Zinnia flowers and leaves have been used for medicinal purposes as an anti-inflammatory and for healing wounds.
- You can dry zinnia flowers to use for wreaths, pot pourri, or dried bouquets.
Conclusion
In conclusion, growing zinnias can be a rewarding experience, adding vibrant colors and cheerful blooms to your garden or containers. Whether you choose to plant them in the ground or in containers, zinnias are relatively easy to grow and maintain, making them a great choice for gardeners of all levels. By following the tips outlined in this guide and paying attention to when and where you plant them, you can enjoy a summer full of beautiful zinnia blooms. So, roll up your sleeves, get your hands dirty, and start growing zinnias to brighten up your outdoor space!
Happy growing!
~ Ruth
Additional resources
https://www.johnnyseeds.com/flowers/zinnias/?start=24&sz=12
https://facts.net/nature/plants/14-intriguing-facts-about-zinnia/
