Ornamental · Plantaginaceae
Snapdragon
Antirrhinum majus
Give snapdragons sun and cool weather and they keep firing out fresh flower spikes across spring and fall.
Full sun
USDA 7–10
0–3 ft · 0.2–0.9 m
Overview
Snapdragons pull off a party trick that never gets old: pinch a bloom at the sides and it snaps open like a tiny dragon's jaw, which is exactly how they got the name. These plants belong to the genus Antirrhinum, and they rocket up tall, flower-packed spikes in nearly every color but true blue. They run on cool weather, hitting their stride through the mild days of spring and fall.
Do not expect this one to hang around for years, though. Snapdragon is a tender perennial that most gardeners run as an annual, since it only pushes through winter in mild spots around USDA zone 7 and warmer. Heights swing from knee-low dwarfs to tall cutting types, so there is a snapdragon ready to edge a bed, fill a border, or load a vase.
Hand it full sun and rich, evenly moist soil, and it charges ahead on little more than regular deadheading. The flowers are safe for pets and people, edible even, which makes it a fun, worry-free pick for a family plot. The only thing that stops the momentum is summer heat, which pauses the blooms until cooler weather kicks them back into gear.
Care
The short version: point snapdragons at full sun, keep their rich soil evenly moist and well-drained, and deadhead often to keep the spikes firing. Run them for spring or fall, since summer heat stalls the show.
Light
Snapdragons flower hardest in full sun. Push them into shade and they stretch and bloom thin, so grab a bright, open spot and the spikes stay sturdy and loaded with color.
Water
Keep the soil evenly moist, since snapdragons have low drought tolerance and sulk when they dry out. Water at the base and keep the leaves dry, which goes a long way toward shutting down rust and Botrytis.
Soil
Plant them in rich, well-drained soil with a near-neutral pH. Loose ground that holds moisture but never bogs down keeps the roots fed and the plants driving forward.
Humidity
Average
Feeding
Hit them with an all-purpose fertilizer in spring as growth takes off, and that is it. One seasonal feeding fuels these cool-weather plants just fine, so there is no reason to pile on more.
Pruning
Deadhead the spent flowers and the plant answers with more spikes and a longer run of bloom. Clip out any damaged or diseased growth while you are at it to keep everything clean and charging.
Size & spacing
Plants shoot up anywhere from 6 to 36 inches (15 to 91 cm) depending on the type. Space them 6 to 10 inches (15 to 25 cm) apart so air rips through and disease has a much harder time getting a grip.
When to plant
Snapdragons chase cool weather, not heat. Get them in the ground in early spring once the last frost clears out, or plant in fall where winters stay mild around USDA zone 8 and warmer, and they will bloom hard through the cool stretches of spring and autumn until the heat reins them in.
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 straight from damp, crowded leaves or the wrong season, and it is easy to get ahead of. Zero in on the lower leaves and stems first, since that is where rust and mold break out. Match your symptom below and jump on it fast before it climbs.
Yellow flecks up top, dusty dark pustules below
That is snapdragon rust, the disease this plant is best known for, and it breaks out when leaves stay wet for 6 to 8 hours in cool 55°F to 70°F (13°C to 21°C) weather. Heat above 80°F (27°C) slams the brakes on it. Strip and bag the spotted leaves, keep the foliage dry, and grab rust-resistant cultivars from the start to stay ahead.
Fix:
- Remove and bag affected leaves
- Apply a labeled systemic fungicide if severe
Twisted yellow leaves with gray fuzz beneath
Downy mildew usually hitches a ride in on infected plugs, so warped, yellowing leaves with gray fuzz underneath are often a problem that showed up with the plant. There is no saving it, so pull it and destroy it. Give anything new a hard look before it joins the bed, cut the overhead watering, and leave room for air to move.
Fix:
- Remove and destroy infected plants
Tan cankers firing up on crowded plants
This is Botrytis gray mold, and it charges in when humidity climbs and the air goes still around packed plants. Cut out the infected stems and any rotting tissue, then open the planting up so air can rush through. Watering at the base instead of overhead keeps the leaves dry and knocks the mold back fast.
Fix:
- Remove and destroy infected plant parts
- Improve air circulation
Bloom power drops off in the heat
Snapdragons are cool-season plants that run out of steam in heat and drought, so the flowers slow or quit once temperatures hold above about 80°F (27°C). This is not a disease, just the wrong season. Cut the plants back, keep them watered, and plenty will fire up again as fall cools off.
Fix:
- Cut plants back and keep them watered; they may rebloom as temperatures cool
Toxicity
Here is a reason to plant with abandon: garden snapdragon is non-toxic to cats, dogs, and horses, and the ASPCA backs it up. The flowers are even edible for people. Tuck it in anywhere pets or kids roam and keep gardening.
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 does zero harm.
Dogs Safe
Snapdragon is safe for dogs, and a nibbled leaf or flower is no big deal, though scarfing down any plant can upset a stomach for a day.
Horses Safe
Horses can graze right up to snapdragons without any risk, since the ASPCA flags no toxicity for them.
Rabbits Safe
Rabbits shrug off snapdragon foliage with no harm done, so a stray plant in their reach is fine.
Livestock Safe
Cattle, goats, and sheep handle snapdragon just fine, since it packs no known toxin for grazing animals.
Birds Safe
Birds can pick at the blooms or seed all they like, since snapdragon poses no toxic threat to them.
People Safe
The flowers are edible and pop up as a garnish, though they can taste bitter, and the plant is safe to have around kids.
Varieties
Snapdragons split mostly by height, from tiny edgers to tall cut-flower spikes. Here are the main classes worth chasing down before you sow.
Dwarf (such as Floral Showers, Snapshot)
Compact plants top out around 6 to 10 inches, perfect for edging a path or packing a container with color.
Medium (such as Liberty Classic, Snaptastic)
Mid-size types climb to roughly 12 to 22 inches and drop right into the middle of a bed or border.
Tall or Rocket (such as Rocket, Potomac, Madame Butterfly)
Tall spikes race from 24 to 60 inches and are grown for cutting, handing you long stems for the vase.
Trailing (such as Candy Showers)
A trailing habit rises about 6 inches and spills to roughly 12 inches, built to pour over the side of a hanging basket.
How to propagate
Snapdragons come almost entirely from seed, kicked off in cool weather for a spring or fall run.
SeedModerate
Sow in cool weather for spring or fall display · Several weeks from germination to transplant size
Nearly all snapdragons launch from seed sown in cool weather for a spring or fall run. Seedlings take several weeks to hit transplant size, so get sowing early. Once the young plants are up, pinch the tips and they branch out bushier, throwing even more flower spikes.
Myths
Snapdragons are tough perennials that charge back every year.
Not really. Antirrhinum majus is a short-lived tender perennial, and most growers run it as an annual. It only comes roaring back in mild climates, roughly USDA zone 7 and warmer, where easy winters spare the crown.
Snapdragons will poison your pets.
Plant away: the ASPCA lists garden snapdragon as non-toxic to cats, dogs, and horses. Let animals roam right past it without a second thought over a nibbled leaf, and know the flowers are even edible for people.
Snapdragons bloom hardest in the summer heat.
They are cool-season bloomers that peak in spring and fall. Once the heat rolls in, the flowers slow or stop until milder weather flips them back on.