How to Grow Snapdragons

patch of snapdragons

The Spruce / Phoebe Cheong

Snapdragons are very popular short-lived garden perennials that are usually grown as annuals. They are a mainstay of classic flower gardens, with infinite uses, from mixed border gardens to flower boxes to patio containers. The common name derives from the shape of the individual flower heads, which resemble the snout of a dragon, and which even open and close in a snapping motion, as often happens when pollinators open the jaws to reach the pollen.

The alternate, lanceolate leaves are arranged in a spiral around the stem. The botanical name, Antirrhinum majus, means "like a snout" and refers to the flower's resemblance to a calf's nose. Snapdragons rely largely on large bumblebees for pollination, as smaller honeybees are unable to open the flower's "jaws".

Bright snapdragon flowers bloom profusely throughout cool weather in intensely saturated colors (almost every hue) and are real standouts in either the spring or fall garden. The flowers start blooming at the bottom of the stalk and work their way up, making for a long period of bloom. Although snapdragons tend to slow down and stop blooming in heat of mid-summer, if you keep them watered, they will perk up and carry your garden through the fall.

From seed germination to flowers can take two to three months, so snapdragons are often started indoors many weeks before the last winter frost.

Botanical Name Antirrhinum majus
Common Name Snapdragon, dog's mouth, lion's mouth, toad's mouth
Plant Type Herbaceous perennial (usually grown as an annual)
Mature Size 6–48 inches (depends on variety), 6–12 inches across
Sun Exposure Full sun to part shade
Soil Type Rich, moist, well-draining
Soil pH 6.2–7.0 (slightly acidic to neutral)
Bloom Time Spring to fall; may slow down in mid-summer
Flower Color White, yellow, pink, red, orange, peach, purple, violet
Hardiness Zones 7–11 (USDA); grown as annuals everywhere
Native Area Mediterranean Europe, Syria, Turkey
Toxicity Non-toxic
different colors of snapdragons
​The Spruce / Phoebe Cheong 
closeup of pink snapdragons
​The Spruce / Phoebe Cheong
Snap dragon by fence
Thang Tat Nguyen / Getty Images

Snapdragon Care

Snapdragons are rather slow-growing when planted from seeds, so they are normally planted from purchased nursery seedlings, which are widely sold in economical six-packs. They can also be grown fairly easily from seeds started indoors weeks before the last winter frost.

Snapdragons do best in rich, well-draining soil in a sunny location, though they will tolerate part shade. Pinching off the stem tips on young plants will make them thicker and bushier, and deadheading the spent flowers will extend the bloom season, often right into the first frost of the late fall or early winter. Snapdragons can repeat bloom throughout the season but they do best in the cool of spring and fall. In cooler climates, they bloom all summer long, and in milder climates, they sometimes bloom throughout the winter.

These short-lived perennials are usually grown as annuals. Even when they do overwinter, snapdragons never seem to bloom as robustly as they did in their first year. However, they should form seed pods in the first year; if you are lucky, they may even self-sow in the garden.

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11 Things You Should Know Before Growing Snapdragons

Light

Your snapdragons will bloom most profusely in full sun to partial shade. Once the temperature heats up, they may stop blooming altogether. Planting them in part shade and keeping them well watered will help them make it through the summer and they will likely bloom again in fall.

Soil

Snapdragons like a neutral soil pH between 6.2 and 7.0, rich in nutrients and well-draining. As short-lived plants, they are not heavy feeders, but adding organic matter will help keep them healthy and blooming.

Water

Snapdragons need adequate watering. Keep seedlings moist for the first few weeks. Once established, snapdragon will need approximately 1 inch of water per week in times of no rainfall. Water near the crown of the plant and avoid overhead watering to keep your snapdragon healthy. Once established, let the top inch of soil dry fully before watering.

Temperature and Humidity

Snapdragons are tender perennials that are hardy in USDA zones 7 to 11. But snapdragons prefer cooler temperatures and are at their best when nighttime temperatures are in the low 40s and daytime temperatures in the low 70s Fahrenheit. For this reason, they are usually grown as annuals to provide garden color in the cooler months of spring and fall.

Once established in the bed and hardened off, snapdragons can withstand sub-freezing temperatures. If you make sure they stay well-watered during cold spells and add a layer of pine straw mulch, they can last for quite some time and will survive quite low temperatures until the chill has passed.

Seedlings grown indoors need to be hardened off for about 10 days to two weeks before planting in the garden.

Fertilizer

Apply fertilizer when the plants first start producing flowers. Use a standard, well-balanced all-purpose fertilizer, such as a 10-10-10 product, at a rate of three pounds for every 100 square feet of the flowerbed. Water well to minimize the risk of nitrogen burns and to help the fertilizer reach the roots.

Illustration of snapdragons
Illustration: The Spruce / Kaley McKean

Snapdragon Varieties

Snapdragons come in many varieties and sizes, from a few inches tall to spires approaching 4 feet. There are tall varieties and dwarf varieties and just about everything in between. Breeders have been playing with snapdragons for years, and now there are even trailing and creeping varieties available. These are great filler plants for containers, baskets, or for planting in garden wall crevices.

Snapdragons are usually sold as multi-color blends, but you can sometimes find individual colors in both seed and seedling. Named varieties come and go every few years, but some of the more classic series include:

  • Rocket series: This is a very dependable multi-colored series that grows about 2 to 3 feet tall. It is a mainstay of the garden center offerings.
  • Madame Butterfly mix: These 24- to 30-inch plants have heavily ruffled flowers in all colors and are an excellent choice for cut flower arrangements.
  • Tutti Fruiti: This shorter 10- to 12-inch series offers unique speckled and striped flowers.
  • Candy Tops mix: These are short, 6- to 8-inch plants in solid tones of yellow, orange, white, red, and rose. They make excellent edging and bedding plants.
  • Chandelier mix: This is one of the better trailing, draping snapdragons, with flowers that are lilac, pink, or yellow.

Remember that there are dozens of different varieties of snapdragons, with new ones introduced every year. Consult seed catalogs to discover the newest introductions.

How Grow Snapdragons from Seed

In milder climates, snapdragons can be winter-sown, simply tossed onto the garden soil in late fall. They can also be direct-sown in the garden a few weeks before the last expected frost. However, snapdragons are relatively slow-growing, so when grown from seeds they are often started indoors six to 12 weeks before the last expected frost.

Use a general seed starting mix or ordinary potting soil, and simply press the seeds onto the surface of the soil. Position the tray under bright lights placed just a few inches above the tray—snapdragon seeds need light to germinate. Keep the light on for a full 16 hours per day, gradually moving it higher as the seedlings grow.

When seedlings have developed about six true leaves (about 3 to 4 inches tall), pinch off the top of the stem, which will encourage branching and bushiness. Transplant snapdragons outdoors a couple of weeks before your last frost date. Snapdragons can handle a light frost or two.

Propagating Snapdragons

Snapdragons are fairly inexpensive to purchase as nursery seedlings and easy to grow from seeds, but if you wish you can also propagate them from stem cuttings.

Cut a 2-inch section of stem just below a leaf node on a healthy parent plant. Remove the lower leaves and dip the bottom of the cutting in rooting hormone. Plant the cutting into seed starter mix or potting soil, covering the pot with a plastic bag or dome to keep the cutting humid. When a good root system develops, you can remove the cover and continue growing in a bright window or under artificial lighting. Transplant outside about the time of the last frost in your area.

 

'arrow' snapdragons
The Spruce / Phoebe Cheong 
snapdragons
baona / Getty Images

Common Pests/ Diseases

Rust fungus can be a significant problem with snapdragons. If rust does appear in a planting, it is best to grow snapdragons in another part of the garden the following year. This plant is also susceptible to mold, fungal leaf spots, downy mildew, wilt, and root rots.

Aphids and spider mites are the most common pest problem, which may require the use of pesticides or horticultural oils in severe infestations.

Tall varieties may need support to avoid toppling over, especially in shady sites where they can grow to be particularly leggy.