Learn how to grow zinnias including different varieties.
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How to Grow: Zinnias
Full sun, part sun
Bloom Period and Seasonal Color
Mid summer until fall in colors such as red, pink, orange, yellow, white and bi-colors
Mature Height x Spread
6 inches to 3 feet x 1 to 2 feet
attracts beneficials, attracts hummingbirds, deer resistant
Zinnias are old-fashioned garden favorites that I in abundance in my garden. The variety of flower shapes, sizes and colors is amazing. These easy to grow annual flowers grow quickly from direct seeding or transplanting to produce single or double petaled blooms all summer long until frost. Zinnias add color to late summer perennial and annual gardens with their showy flowers and non-stop blooming habit. Their needs are simple. Give them plenty of water and grow them in full sun in an airy location to avoid late season diseases. Not only are they beautiful flowers in the garden or containers, zinnias attract butterflies and hummingbirds and can be used as a cut flower indoors in arrangements.
Where, When and How to Plant
Plant seeds directly in a full sun location into compost amended garden beds on well-drained soil in spring around the last frost date for your area. For quicker blooms, consider buying transplants from local garden centers in spring or starting seeds indoors 4 weeks before your last frost date under grow lights. Space plants or thin seedlings to 8 to 18 inches apart, depending on the size of the variety, in beds.
Keep plants well watered and fertilized monthly with an organic plant food. Pinch out the growing tips of young transplants in spring to promote side branching, bushiness and more flowering.
Regional Advice and Care
Deadhead spent flowers all summer long. By late summer in New England, powdery mildew can cause the leaves to dieback and the plant to look unsightly. Space plants further apart to promote air circulation, select disease resistant varieties, and pull and compost diseased plants to reduce this disease. Japanese beetles love zinnias. Trap the beetles, cover prized plants with a row cover and spray Neem oil to kill adults and spray beneficial nematodes to kill the beetle larvae.
Companion Planting and Design
Zinnias are good additions to a perennial flower border. Grow tall varieties in the middle and back of the border near spring flowering perennials, such as peonies, iris and daylilies, to add color in late summer. Plant smaller mounding varieties, such as the Profusion Series, in the front of borders or in containers. Zinnias are good additions to the cut flower garden as well. I like growing them in the vegetable garden to attract beneficial insects and add color.
‘Blue Point’, ‘State Fair’ and ‘Benary’s Giant’ are tall, large, double-flowered, colorful mixes that are great for cutting and growing in gardens. The ‘Profusion Series’ is a mounding mix of many colors that produces small, single flowers on disease resistant 1- foot tall plants. They grow well in containers. ‘Oklahoma series’ is a tall, double-flowered, cut flower variety with good powdery mildew resistance. The ‘Ruffles Series’ features, double-flowered, frilly petaled flowers with good disease resistance.
Excerpted from my book, New England Getting Started Garden Guide.
This common mid to late summer annual flower wasn’t always the darling of the garden. When it was first discovered in its native Mexico by the Spanish it was so unattractive it was called “mal de ojos” or sickness of the eyes. Not a great beginning for a flower. But through years of breeding, the zinnia has been transformed into one of our favorite garden flowers.
Zinnias are native to the Americas and like the chrysanthemums and dahlias, there are a variety of flower sizes and shapes such as cactus, dahlia, button, and doubles. They come in all colors of the rainbow. Some of my favorites are the ‘Profusion’ zinnias for their small, mounding habit, single and double flowers and variety of flower colors. ‘Zowie Yellow Flame’ has an ostentatious name that matches the bright yellow and red colored flowers on this 2 foot tall plant. ‘Zinderella Peach’ is a new, unique salmon colored double flower with cream-to-rose petals on 3 to 4 foot tall plants. If you have trouble with powdery mildew disease try the ‘Oklahoma’ series. These double flowered button type comes in colors such as salmon and yellow on 3 foot tall plants.
Zinnias are easy to grow directly sown from seed in spring or as transplants started indoors about 4 weeks earlier. They need full sun and well-drained, fertile, moist soil to get started. We like to plant zinnias in among our perennial flowers to add mid and late season color. We also grow them in the vegetable garden for beauty, to attract beneficial insects and for cutting. Check out gardens now to mark down varieties you’d like to try in your own yard next year.