If you're looking for a prolific annual flower for gardens and bouquets in a wide range of colors, try zinnias. The plants range from low growing, to tall and statuesque. Flowers come in all the colors of the rainbow depending on the variety. Group them in a flower or vegetable garden for color and to attract bees and butterflies.
When & Where to Plant Zinnias
Light: Zinnias grow and flower best in full sun. They can flower in part shade, especially in warmer climates with afternoon shade, but they may be more susceptible to disease and have fewer flowers.
Soil: Zinnias grow best on fertile, well-drained soils high in organic matter. Well-drained soil is important because zinnia seedlings can be prone to rotting in cool, wet soils.
Spacing: Plant zinnia seeds a few inches apart in rows or clumps. Thin to 8 to 18 inches apart, depending upon the variety, once the plant has grown four leaves.
Planting: Plant zinnias in spring after all danger of frost has passed, around the same time you'd plant tomatoes. Zinnias are easy to grow directly-seeded into the garden. For sooner blooms, start seeds indoors 4 to 6 weeks before your last frost date.
How to Grow Zinnias Throughout the Season
Growth Habit:Zinnias come in a wide variety of plant sizes. Some are low-growing. 1-foot tall plants with a mounding habit. Others are 3-foot tall plants with big flowers. Plant the right variety for your usage and that your space allows. Mounding varieties have smaller flowers and produce more ornamental looking plants. Taller varieties are often used for cutting and are best grown in rows or clumps for a better visual effect.
FAQs
April or May is the best time to plant zinnia seeds in a greenhouse or cold frame or on a bright windowsill, for earlier flowering. Zinnias are half-hardy annuals that dislike the cold, so don't sow them under cover too early in spring because they shouldn't be planted out until the weather has warmed sufficiently.
What month do you plant zinnia seeds? ›
April or May is the best time to plant zinnia seeds in a greenhouse or cold frame or on a bright windowsill, for earlier flowering. Zinnias are half-hardy annuals that dislike the cold, so don't sow them under cover too early in spring because they shouldn't be planted out until the weather has warmed sufficiently.
Can I just scatter zinnia seeds? ›
Can I just Scatter Zinnia Seeds? I love that zinnia seeds can be scattered or evenly placed in your soil. It is recommended that they be planted ¼ inch deep in moist soil. Most packets say that you space seeds about 6 inches apart, with rows at least 12 inches apart.
Should I soak zinnia seeds before planting? ›
Zinnia seeds do not require any treatment (eg soaking, stratification) before sowing. Zinnia seeds can be sown directly into the garden OR seedlings can be raised in trays or other containers and transplanted to the garden once established.
How do you plant zinnia seeds directly in the ground? ›
Plant the seeds only about ¼” – ½” deep and you should see seedlings sprout in four to seven days. Once the seedlings reach about 3” tall, thin them to maximize air circulation, and prevent powdery mildew.
Do zinnias do better in pots or in the ground? ›
Zinnias are versatile and adaptable plants that thrive in containers just as well as they do in traditional garden beds. If you just sighed in relief, I can relate because I did too when I heard this fabulous news!
Do zinnias come back every year? ›
Zinnias are annuals in most areas of the country that have four seasons, including a cold winter. This means they last for one season. If you want zinnias every year, you will have to replant every spring. Zinnias are not cold tolerant, so check your last freeze date for your growing zone.
Can I just throw down wildflower seeds? ›
Make certain to remove all the roots of old grass and weeds or they'll grow back with enthusiasm. We don't recommend just throwing the seed out in the field or into the grass; anyone who's tried scattering seed without removing other plants has been sorely disappointed when their wildflowers don't come up.
Are zinnias hard to grow from seed? ›
Zinnias' pointy seeds, shaped like little arrowheads, require only basic garden prep to sprout: sow them in well-drained soil, where there's full sun and lots of summer heat, and you'll have tiny seedlings in days, with flowers powering up in just a few weeks. No perennial can claim that speed!
Do zinnias prefer sun or shade? ›
Light: Zinnias grow and flower best in full sun. They can flower in part shade, especially in warmer climates with afternoon shade, but they may be more susceptible to disease and have fewer flowers. Soil: Zinnias grow best on fertile, well-drained soils high in organic matter.
"Whether seeding directly in beds or germination trays, zinnia seeds should be sown to a depth of a 1/4-inch into deep, loamy soil," she says.
Why won't my zinnia seeds germinate? ›
Too much or too little water is the most likely reason for seeds not germinating. With too little or no water, seeds remain dormant. With too much water, seeds become susceptible to rot or infection from soil-borne fungi (also referred to as "dampening off").
What not to plant with zinnia? ›
Garden staples like tomatoes, cucumbers, asparagus, and peppers are just a few that work nicely with zinnias. Dahlias, marigolds, and salvias are among ornamental plants that can be cultivated as zinnia companion plants. However, lavender and other herbs that favor dry, sandy soils should not be used.
How do I keep zinnias blooming all summer? ›
Deadheading, in essence, tricks the plant into reblooming. By repeatedly deadheading zinnias throughout the summer, you can keep plants in the flowering stage, provide long-lasting color. Deadheading also keeps plants looking their best.
Do zinnias like full sun? ›
Light: Zinnias grow and flower best in full sun. They can flower in part shade, especially in warmer climates with afternoon shade, but they may be more susceptible to disease and have fewer flowers. Soil: Zinnias grow best on fertile, well-drained soils high in organic matter.
What is the lowest temperature zinnias can tolerate? ›
Ideal range 70-85°F day/60-70°F night for Zinnia growth and flowering. Below 50°F risks root rot, diseases, and growth slowdown. Protect with strategic planting, shade cloths, and frost blankets.
