Snapdragons: Plant Care & Growing Guide

Snapdragons (Antirrhinum majus) are popular perennials usually grown as annuals with a short-lived blooming period. The name comes from the shape of the individual flower heads, which look like the snout of a dragon.

Bright snapdragon flowers bloom well in cool weather with intensely saturated colors (in almost every hue) and are real standouts in either the spring or fall garden. They come in many varieties and sizes; you can find one to suit your needs at a few inches, four feet, or anything in between.

Snapdragons are great plants for containers, baskets, or filling garden wall crevices as they can fit a variety of areas. From germination to flowering takes about two or three months, and as a result are often started indoors weeks—or even months—before the last frost.

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.

They do best in rich, well-draining soil in a sunny location, though they'll tolerate part shade. Pinching off the stem tips on young plants will make them bushier, and deadheading the spent flowers will extend the bloom season, often right until the first frost.

Light

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

Keep seedlings moist for the first few weeks. Once established, snapdragon will need approximately one 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 7-11. They prefer cooler temperatures and are at their best when nighttime temperatures are in the low 40s and daytime temperatures are in the low 70s. For this reason, they are usually grown as annuals.

Once established, 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.

Snapdragons prefer average humidity within the 40 to 70 percent range.

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 after fertilizing.

Types of Snapdragon

Snapdragons are usually sold as multi-color blends, but you can sometimes find individual colors in both seeds and seedlings. 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 2-3 ft. 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 Frutti: 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.

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.

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

How Grow Snapdragons from Seed

In milder climates, snapdragons can be winter-sown. They can also be direct-sown in the garden a few weeks before the last expected frost. Snapdragons are relatively slow-growing, so 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 press the seeds onto the surface of the soil. Position the tray under bright lights—the seeds need light to germinate. Keep the light on for 16 hours per day. When seedlings have developed about six true leaves, 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.

Overwintering

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.

Common Pests & Plant 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.

How to Get Snapdragon to Bloom

Snapdragons are known for their colorful blooms. They start blooming in early spring and keep blooming all season long. They are short-lived perennials that act like annuals and don't usually flower for more than one season.

The right amount of sunlight is the secret sauce to getting your snapdragons to bloom. From full sun to partial shade, adjusting the amount of sun your plants get is the answer. Deadheading the dying flowers will keep your plant blooming abundantly.

Common Problems With Snapdragon

Snapdragons are a never-go-out-of-style summertime bloom. They're bright and cheery, and memorable additions to the summer months. But sometimes, snapdragons have easy-to-fix problems:

Wilting Leaves, Fewer Flowers

Snapdragons will start to falter if they get too much heat and sunlight. Move them to a cooler, shadier spot, and trim them down to encourage new blooms and less wilting.

Yellow and Brown Flecks on the Leaves

Snapdragons often get a fungal disease called snapdragon rust: yellow flecks are the first sign, and those flecks may get darker and larger, with brown or black centers.

To treat snapdragon rust, stop it before it starts. Thin out your plants and let air circulate around them. Also, don't water your snapdragons at night.

Plants Toppling Over

In shady spots, where snapdragons can get particularly leggy, taller varieties may get top-heavy and fall over. The fix is easy: protect plants with supports to keep them standing tall.