Zinnias

How to Plant, Grow, and Care for Zinnia Flowers

Growing Zinnia Flowers

Zinnias are one of the easiest plants to grow, as they grow quickly and bloom heavily. Zinnia flowers make a massive burst of color in your garden, and they attract butterflies.

Zinnias are annuals, so they grow for one season and make great cutting flowers, but do not come back in subsequent years. They have bright, solitary, daisy-like flowerheads on a single, erect stem. The most common zinnia is “dahlia-flowered” and grows up to three feet tall. Other types are “cactus-flowered.”

Use in an annual or mixed border garden. Smaller zinnias are suitable for edging, windowboxes, or other containers. The narrow-leaf zinnia also works well in hanging baskets.

Planting

You should really grow zinnia from seed, as they do not like to be transplanted as nursery plants and do not often thrive. From seed, they will grow very quickly in the right conditions.

  • Do not seed until the last frost has passed. See your local frost dates.
  • Choosing a location that gets full sun is essential. Zinnias can stand a minimum daytime temperature of 60 degrees F, and a range of 74 to 84 degrees F is preferred.
  • Zinnias are adaptable, but the ideal soil is nice and fertile, humus-rich, and well-drained. Soil pH should be between 5.5 and 7.5. If soil is amended with compost, the flowers will grow more quickly. Learn more about soil amendments and preparing soil for planting.
  • Sow zinnia seeds only ¼-inch deep.
  • Space plants 4 to 24 inches apart, depending on variety. (Many common varieties are planted 6 inches apart within the row and 2 feet in between rows.) See back of seed package for variety-specific advice.
  • You’ll see zinnia seedlings in only 4 to 7 days for most varieties.
  • When seedlings reach three inches tall, thin them so that they’re 6 to 18 inches apart to maximize air circulation.
  • Sow in succession for a longer flowering display.

Care

  • Deadhead zinnia flowers to prolong flowering.
  • Maintain moderate soil moisture and fertilize lightly.
  • Zinnias are annuals and will die with the first frost.

Pests/Diseases

  • Bacterial and fungal spots, powdery mildew, and bacterial wilt may affect zinnias. Minimize wetting of foliage to avoid disease.
  • Caterpillars, mealybugs, and spider mites also cause problems. Avoid spraying and tolerate some leaf damage unless the situation is uncontrolled.
  • Luckily, zinnias are deer-resistant, so they might help keep nearby flowers from being eaten.

Harvest/Storage

  • Zinnias generally take 60 to 70 days from seed to flower (though it depends on conditions).

Recommended Varieties

Wit & Wisdom

  • The small, narrow-leaf zinnias make nice dried flowers, too.
  • It is said that zinnias symbolize thoughts of absent friends. Learn about more flower meanings here.

Botanical Name: 

Zinnia elegans

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