The Ultimate Guide to Growing Zinnias: A Vibrant Addition to Your Garden
Zinnias are beautiful show stoppers that come in a wide range of colors and shapes. They are hardy and beginner-friendly. Zinnias are annuals and will give you a burst of color through to hard frost.
Zinnias offers a burst of color that brightens any garden space.
In this guide, we'll walk you through everything you need to know to grow zinnias successfully, from selecting the right varieties to ensuring a bountiful bloom.
Why Grow Zinnias?
Zinnias are annual flowers, meaning they complete their life cycle in one growing season. They are known for their vibrant colors, ranging from deep reds and purples to soft pinks, yellows, and whites. Zinnias are also incredibly versatile, thriving in various garden settings, from traditional flower beds to container gardens.
Benefits of Growing Zinnias:
Long Blooming Period: Zinnias bloom from late spring until the first frost, providing color and interest throughout the growing season.
Attract Pollinators: Zinnias are a favorite of butterflies, bees, and hummingbirds, making them an excellent choice for pollinator gardens.
Easy to Grow: Zinnias are low-maintenance flowers that require minimal care, making them ideal for gardeners of all skill levels.
Cut Flower Potential: Zinnias make beautiful cut flowers, perfect for adding a splash of color to indoor arrangements.
Choosing the Right Zinnia Varieties
There are several varieties of zinnias to choose from, each offering different flower shapes, sizes, and colors. When selecting a variety, consider your garden space and desired aesthetic.
Zowie Zinnia - Zinnia elegans
Popular Zinnia Varieties:
Zinnia elegans: The most common variety, known for its large, showy blooms. Available in a wide range of colors, Zinnia elegans can grow up to 4 feet tall.
Zowie! is one cultivar that really brightens up an area. It’s great for the front fence or by the mailbox because it tolerates heat and tough conditions.
Benary's Giant is a fabulous cultivar that is very popular, vigorous, and popular with cut flower farmers.
State Fair Mix is one of my favorite cultivars. It’s reliable and has long blooms.
Zinnia angustifolia: A more compact variety with smaller, daisy-like flowers. Known as the narrow-leaf zinnia. Native to the southwest. This variety is excellent for borders or container gardens.
Profusion is a great cultivar.
Zinnia haageana: Also known as Mexican zinnias, this variety produces smaller, bi-colored blooms and is more tolerant of heat and drought.
One cultivar 'Aztec Orange', has beautiful double orange flowers. Jazzy Mix is another great one.
Zinnia flowers come in a number of shapes, including “beehive,” “button,” and “cactus.” My suggestion is that you pick the type and color you think is pretty and fits in with your landscaping plan.
Urban Gardeners
Zinnias do well in pots and are great for urban gardeners. There are some great dwarf varieties like Zahara which comes in several colors.
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Planting Zinnias: Step-by-Step Guide
Zinnias are best planted after the last frost date in your area when the soil has warmed up. They thrive in full sun and well-drained soil.
1. Prepare the Soil:
Choose a sunny spot in your garden that receives at least 6-8 hours of direct sunlight each day. Zinnias prefer well-drained soil with a pH between 5.5 and 7.5. If your soil is heavy or clay-like, amend it with some organic matter like compost to improve drainage.
Sprinkle in some well-rotted manure but don't add any additional fertilizer. They are light feeders. Zinnias are very pH tolerant and pretty flexible as far as soil type.
2. Planting Seeds:
Zinnias are easy to grow from seed and can be directly sown in the garden. They usually take 60–70 days to bloom from seed, depending on the variety and weather conditions.
Sow zinnia seeds directly into the garden bed, spacing them about 9-12 inches apart, depending on the variety.
Cover the seeds lightly with soil, about 1/4 inch deep. Water the seeds gently to keep the soil moist but not waterlogged.
3. Germination:
Zinnia seeds typically germinate within 7-10 days. During this period, keep the soil consistently moist. Once seedlings emerge, thin them to ensure proper air circulation and reduce the risk of disease.
They do like a warm germination temp of 70-75 degrees Fahrenheit. A heat mat works well. Once they sprout you can take it down to 65.
4. Transplanting (if starting indoors):
If you want to get a jump on the season start them indoors 4 weeks before the last frost. They are not big fans of being transplanted so I recommend jiffy pots. Before planting out give them a good soak and gently peel off the bottom so the roots can easily get free.
If you start zinnias indoors, transplant them into the garden after they have developed a few sets of true leaves and the threat of frost has passed. Space the transplants according to the recommended spacing for the variety.
5. Succession planting
Zinnias enjoy warm sunny weather with a minimum daytime temperature range of 60–84°F.
Succession planting works well with zinnias, especially for different types. I plant 3 times. Mid-May, mid-June, and mid-July. That way I am getting 5 months of bloom before frost hits.
Zinnias do great in a mixed garden. This is one of the many gardens at my sons work. This one is my favorite with zinnias, calendula, allium, shrubs and more. A garden like this will attract tons of pollinators.
Caring for Your Zinnias
Zinnias are relatively low-maintenance but benefit from some basic care to ensure healthy growth and abundant blooms.
1. Watering:
Zinnias are draught tolerant but dry weather can cause them not to bloom. So while they don't need a lot of water make sure they get about an inch every other week.
Water zinnias at the base of the plant to avoid wetting the foliage, which can lead to powdery mildew.
Keep the soil evenly moist, especially during dry periods, but be careful not to overwater.
2. Fertilizing:
Zinnias are not heavy feeders, but you can give them a boost with a balanced, all-purpose fertilizer once or twice during the growing season.
My favorite is Alaska fish emulsion!
Avoid excessive nitrogen, as it can lead to lush foliage at the expense of flowers.
3. Deadheading:
Regularly remove spent blooms (deadheading) to encourage continuous flowering. This also helps keep the plants looking tidy.
4. Trellis
Taller varieties need support. One option is flower netting that you put horizontally. So put in some stakes or metal fence posts and then stretch the netting 6 - 8 inches above the ground.
Taller varieties need support. One option is flower netting that you put horizontally. So put in some stakes or metal fence posts and then stretch the netting 6 - 8 inches above the ground.
5. Pest and Disease Management:
Zinnias can be susceptible to powdery mildew, especially in humid conditions. Ensure good air circulation and water at the base to prevent this. I am a big fan of Neem Oil.
I have a very thorough video on downy and powdery mildews.
My very popular video on how to deal with mildews organically
Keep an eye out for common garden pests like aphids and spider mites. If necessary, treat with insecticidal soap or neem oil.
Zinnias are butterfly magnets. Red zinnias are best if you want to attract monarchs.
Harvesting Zinnias for Cut Flowers
One of the joys of growing zinnias is bringing their beauty indoors. To harvest zinnias for cut flowers.
Harvesting will encourage more blooms. Go to where the stem branches and cut right above that branching.
Choose flowers that are fully open, as they do not continue to mature after being cut.
Cut the stems in the morning when they are fully hydrated.
Place the cut stems in water immediately and enjoy your fresh blooms indoors for up to a week.
Saving Seed
Zinnias will reseed and it's also super easy to save seed. Collect blossoms that are at least halfway brown and place them bloom down in a paper bag until the seeds shatter. Then store the seeds in a cool dry place till the next spring.
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Companion Planting with Zinnias
Zinnias make excellent companion plants in the garden. Their bright blooms attract beneficial insects and pollinators, which can help protect nearby vegetables and other flowers.
Attracts Wildlife
If you have honey bees or wish to support native bees zinnias produce a lot of pollen. They are butterfly magnets. Red zinnias are best if you want to attract monarchs. And hummingbirds love them.
Protects From Wildlife!
Another good thing about zinnias is they are fairly deer-resistant and not a favorite.
Best Companion Plants for Zinnias:
Tomatoes: Zinnias attract pollinators and beneficial insects that help keep tomato pests in check.
Basil: This herb benefits from the pollinator activity that zinnias attract.
Marigolds: Planting marigolds with zinnias creates a vibrant, pest-resistant border.
Conclusion: A Garden Full of Zinnias
Zinnias are a fantastic addition to any garden, offering a riot of color and attracting a variety of pollinators. With their ease of care and versatility, they are a must-have for gardeners looking to create a vibrant, lively space. Whether you're planting them in garden beds, borders, or containers, zinnias are sure to bring joy and beauty to your outdoor space.
Ame Vanorio is the founder of Fox Run EEC and an avid gardener. She has authored several books on organic gardening and wildlife rehabilitation.
Sometimes we get so caught up in gardening out in the sun that we forget that many fruits are native to woodland areas. Native fruits are often shade tolerant and will produce fruits in 4-6 hours of sun a day.
These 9 fruits will give you great yield in shade and are quite hardy.