Seed Grown Snapdragons – How To Grow Snapdragons From Seed

By: Mary H. Dyer, Credentialed Garden Writer

Everybody loves snapdragons – old-fashioned, cool-season annuals that produce spikes of long-lasting, sweet-smelling blooms in every color of the rainbow, except blue. Once established, snapdragons are remarkably self-sufficient, but planting snapdragon seeds can be tricky. Want to try your hand at seed-grown snapdragons? Read on to learn the basics of snapdragon seed propagation.

When to Plant Snapdragon Seeds

When planting snapdragon seeds, the optimum time to start snapdragon seeds indoors is about six to ten weeks before the last frost in spring. Snapdragons are slow-starters that germinate best in cool temperatures.

Some gardeners have good luck planting snapdragon seeds directly in the garden. The best time for this is after the last hard frost in spring, as snapdragons can tolerate light frost.

How to Grow Snapdragons from Seed Indoors

Fill planting cells or seedling pots with well-drained potting mix. Water the mix well, then allow the pots to drain until the mix is evenly moist but not soggy.

Sprinkle snapdragon seeds thinly on the surface of the moist potting mix. Press the seeds lightly into the potting mix. Don’t cover them; snapdragon seeds won’t germinate without light.

Place the pots where temperatures are maintained at about 65 F. (18 C.). Bottom heat isn’t necessary for snapdragon seed propagation, and the warmth may inhibit germination. Watch for the seeds to sprout within a couple of weeks.

Place the plants 3 to 4 inches (7.5 to 10 cm.) below fluorescent light bulbs or grow lights. Leave the lights on for 16 hours per day and turn them off at night. Planting snapdragon seeds on windowsills rarely works because the light isn’t bright enough.

Be sure the seedlings have plenty of air circulation. A small fan placed near the seedlings will help prevent mold, and will also encourage stronger, healthier plants. Water as needed to keep the potting mix evenly moist, but never saturated.

Thin the seedlings to one plant per cell when the snapdragons have two sets of true leaves. (True leaves appear after the initial seedling leaves.)

Fertilize the snapdragon seedlings three to four weeks after planting using a water-soluble fertilizer for indoor plants. Mix the fertilizer to half strength.

Transplant the snapdragons into a sunny garden spot after the last hard frost in spring.

Planting Snapdragon Seeds Directly in the Garden

Plant snapdragon seeds in loose, rich soil and full sunlight. Sprinkle snapdragon seeds lightly on the surface of the soil, then press them lightly into the soil. Don’t cover the seeds, as snapdragon seeds won’t germinate without light.

Water as needed to keep the soil evenly moist, but be careful not to overwater.

Note: Some gardeners are convinced that freezing seeds for a couple of days increases the chances of successful snapdragon seed propagation. Others think this step is unnecessary. Experiment to discover which technique works best for you.

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Snapdragon (Antirrhinum majus), an old-fashioned garden flower, is available in white and shades of bright and pastel colors. Depending on the species, snapdragons range from 6-inch-tall dwarfs to 3-foot-tall giants. There are more than 230 varieties available to gardeners. These include various flower shapes like the classic snapdragon shapes, the double bell shape and azalea shapes. Snapdragons are cool-season flowers that stop producing blossoms when the temperature hits 80 degrees Fahrenheit. Commonly planted as an annual in areas with freezing temperatures, snapdragons act as perennials in U.S. Department of Agriculture plant hardiness zones 9 through 11.

I'd like to save Snapdragon 'Rocket Red' to grow next year

I have mostly perennials that I suppliment with annuals. Usually, I just buy new, but after growing Snapdragons for the first time this year I'd love to save them somehow. I'm growing 'Rocket Red'.

I bought a 6-pack in spring, but didn't get around to planting them for a while. By the time I did, they were pretty sad looking so I cut them back about half way. They're also in part shade since most of my garden is shady. They started blooming in early August and look beautiful. Each day they get more buds.

I've read that the 'Rocket' series get tall and leggy, but these have not (maybe because I had to cut them back when I planted them).

I really love these and would like to grow them again next year.

Is there any way these can be saved for next spring. either cuttings, seeds, root cuttings or even whole plants tucked away in a garage? I've read seeds may not grow true. I live in Zone 5a.

Are they a good candidate for Winter Sowing? It's warmer up near the back of my house since we get full sun there.

Any help would be greatly appreciated. I'm not a newbie gardener, but kind of a newbie at saving plants over winter. I've saved cutings of Coleus and assorted house plants with soft stems and even let some seeds dry on a few perennials and scattered them, but that's all.

Growing tips

  • Snapdragons bloom best in well-drained, moist soil, in cool late-spring or early-summer temperatures. They can tolerate light shade but bloom much better in full sun.
  • Snapdragons tend to stop producing flowers when hot weather arrives, but they will usually re-bloom when the weather cools off in late summer if you cut back the spent flower stalks.
  • Snapdragons are available in a broad range of heights, so they may be used in many ways in the garden. Small cultivars work well as an annual ground cover, as an edging, or in pots or window boxes. The spiky form of taller cultivars adds an attractive accent to annual and mixed borders.
  • Tall snapdragon cultivars also make remarkably long-lasting cut flowers.

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