Ornamental · Plantaginaceae
Snapdragon
Antirrhinum majus
Plant it for cool spring and fall color, and the snapdragon throws up spire after spire of bloom.
Full sun
USDA 7–10
0–3 ft · 0.2–0.9 m
Overview
Snapdragons earn their name from the way each flower snaps open and shut when you pinch its sides, a trick that has kept children busy in gardens for generations. The plant belongs to the genus Antirrhinum and sends up tall spikes packed with flowers in nearly every color but true blue. It is a cool-season favorite, happiest in the mild stretches of spring and fall.
Despite the upright drama, snapdragon is short-lived. It is a tender perennial that most gardeners grow as an annual, since it only overwinters in mild climates around USDA zone 7 and warmer. Heights run from ankle-high dwarfs to cutting types that reach your waist, so there is a snapdragon for the front edge of a bed, the middle of a border, or a vase indoors.
Give it full sun and rich, evenly moist soil, and it asks for little beyond regular deadheading. The flowers are safe around pets and people and are even edible, which makes this a worry-free choice for a family garden. The main catch is heat, which shuts down the bloom until cooler weather returns.
Care
The short version: full sun, rich and evenly moist soil that drains well, and steady deadheading to keep the spikes coming. Grow it for spring or fall, since summer heat stalls the bloom.
Light
Snapdragons flower best in full sun. They will stretch and bloom thinly in shade, so give them an open, bright spot to keep the spikes sturdy and packed with color.
Water
Keep the soil evenly moist, since snapdragons have low drought tolerance and resent drying out. Water at the base and keep the foliage dry, which goes a long way toward holding off rust and Botrytis.
Soil
Plant in rich, moist, well-drained soil with a near-neutral pH. Loose ground that holds moisture but never waterlogs gives the roots the steady supply they want.
Humidity
Average
Feeding
Feed with an all-purpose fertilizer in spring as growth picks up. A single seasonal feeding suits these cool-weather plants, so there's no need to push them with more.
Pruning
Deadhead spent flowers to keep new spikes coming and stretch the bloom. Clear out any damaged or diseased growth at the same time to keep the plant clean and open.
Size & spacing
Plants range from 6 to 36 inches (15 to 91 cm) tall depending on the type. Set them 6 to 10 inches (15 to 25 cm) apart so air moves freely between them and disease has a harder time taking hold.
When to plant
Snapdragons run on cool weather, not warmth. Plant them out in early spring once the last frost has passed, or in fall where winters stay mild around USDA zone 8 and warmer, and they bloom through the cool stretches of spring and autumn before heat slows them down.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Early spring after the last frost, or in fall in mild zones (about USDA zone 8 and warmer)
- Harvest: Blooms in cool weather of spring and fall (and summer in cool climates); flowering slows in summer heat
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
Most snapdragon trouble comes from damp, crowded foliage or the wrong season. Watch the lower leaves and the stems first, where rust and mold show up early. Match what you see below, then act before it climbs the plant.
Yellow spots up top with dark dusty pustules underneath
This is snapdragon rust, the plant's signature disease, and it spreads when leaves stay wet for 6 to 8 hours in cool weather of 55°F to 70°F (13°C to 21°C). Heat above 80°F (27°C) holds it back. Strip and bag the marked leaves, keep water off the foliage, and choose rust-resistant cultivars to begin with.
Fix:
- Remove and bag affected leaves
- Apply a labeled systemic fungicide if severe
Twisted yellow leaves with gray fuzz on the undersides
Downy mildew usually arrives on infected plugs, so distorted, yellowing leaves with grayish spores beneath are often a problem you bought rather than one you grew. There's no saving an infected plant, so pull and destroy it. Inspect anything new before it joins the bed, skip overhead watering, and give plants room for airflow.
Fix:
- Remove and destroy infected plants
Tan stem cankers and fuzzy gray growth on damp plants
Botrytis gray mold takes hold when humidity runs high and air sits still around crowded plants. Cut out the infected stems and decaying tissue, then open the planting up so air can move through. Watering at the base instead of overhead keeps the foliage dry and slows the mold down.
Fix:
- Remove and destroy infected plant parts
- Improve air circulation
Flowering stalls once summer turns hot
Snapdragons are cool-season plants with little tolerance for heat or drought, so blooming slows or stops once temperatures hold above about 80°F (27°C). This isn't a disease, just the wrong weather. Cut the plants back, keep the soil watered, and many will flower again as fall cools off.
Fix:
- Cut plants back and keep them watered; they may rebloom as temperatures cool
Toxicity
Good news for a household with pets: garden snapdragon is non-toxic to cats, dogs, and horses, and the ASPCA backs that up. The flowers are even edible for people. You can plant it anywhere animals or children might wander without a second thought.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
The ASPCA lists garden snapdragon as non-toxic to cats, so a curious chew won't poison one.
Dogs Safe
Snapdragon is safe for dogs, and a nibbled leaf or flower is no cause for alarm. Gorging on any plant can still upset a stomach for a day.
Horses Safe
Horses can graze near snapdragons without risk, since the ASPCA flags no toxicity for them.
Rabbits Safe
Rabbits face no poisoning from snapdragon foliage, so a stray plant in their reach is fine.
Livestock Safe
Cattle, goats, and sheep tolerate snapdragon without trouble, and it carries no known toxin for grazing animals.
Birds Safe
Snapdragon poses no toxic threat to birds picking at the blooms or seed.
People Safe
Snapdragon flowers are edible and turn up as a garnish, though they can taste bitter. The plant is safe to have around children.
Varieties
Snapdragons are sorted mostly by height, from tiny edgers to tall cut-flower spikes. These are the main classes worth knowing before you sow.
Dwarf (such as Floral Showers, Snapshot)
Compact plants stay around 6 to 10 inches tall, which makes them a tidy choice for edging a path or filling a container.
Medium (such as Liberty Classic, Snaptastic)
These intermediate types reach roughly 12 to 22 inches and slot neatly into the middle of a bed or border.
Tall or Rocket (such as Rocket, Potomac, Madame Butterfly)
Tall spikes from 24 to 60 inches are grown mainly for cutting, giving you long stems for the vase.
Trailing (such as Candy Showers)
A cascading habit rises about 6 inches and spills to roughly 12 inches, built to tumble out of a hanging basket.
How to propagate
Snapdragons are grown almost entirely from seed, started in cool weather for a spring or fall show.
SeedModerate
Sow in cool weather for spring or fall display · Several weeks from germination to transplant size
Most snapdragons are grown from seed sown in cool weather for a spring or fall display. Seedlings take several weeks to reach transplant size, so start early. Once the young plants are up, pinch the tips to push out bushy, branching growth and more flower spikes.
Myths
Snapdragons are reliable perennials that come back every year.
Antirrhinum majus is a short-lived tender perennial, and most gardeners treat it as an annual. It only returns from year to year in mild climates, roughly USDA zone 7 and warmer, where winters stay gentle enough to spare the crown.
Snapdragons are poisonous to pets.
The ASPCA lists garden snapdragon as non-toxic to cats, dogs, and horses. You can plant it where animals roam without worrying about a nibbled leaf, and the flowers are even edible for people.
Snapdragons bloom best in the heat of summer.
They are cool-season bloomers, at their best in the spring and fall. Once summer heat settles in, flowering slows or stops until the weather turns mild again.