Every year, the National Garden Bureau, a non-profit organization promoting the pleasures of home gardening, selects one annual, one perennial, one edible plant and one bulb to celebrate. It’s a great way to discover a new plant or to learn a bit more about a plant you may already be growing.
Let’s look at the annual chosen for 2019, the snapdragon.
The garden snapdragon (Antirrhinus majus), of the Plantaginaceae family, originated around the Mediterranean Sea, but is now found as a garden escapee in many countries worldwide. It may self-sow modestly in your own garden, but rarely does so enough to be a pest.
Its curious flowers give it both its botanical and common names. Anti (like) and rhin (snout) are from Greek and refer to the flowers that look like an animal’s snout, but I think the English name, snapdragon, that dates to the 1570s, is a far more interesting choice. As many children have discovered, the bilabiate flower opens when you press lightly on its sides with the thumb and forefinger, revealing a mouth that snaps shut when released, like an angry dragon. Cool, isn’t it!
We used to play snapdragon wars when we we kids, opening and closing harvested flowers and snarling and growling like a dragon. I recall scaring my little brother with the idea that if he put his pinky finger inside, the flower would bite it off … probably something an older child had told me.
As for majus, it means tall, as the original species was an upright plant up to 4 feet (120 cm) in height.
Bumblebee visiting snapdragon flowers. Source: tubelessrim, youtube.com
The snapping dragon effect of the bloom is designed to ensure exclusivity to its primary pollinator, the bumblebee. Honeybees and other insects are too light to open the flower, but the heavier bumblebee simply lands on the lower lip, pushes and it opens right up. Then the insect disappears inside looking for the nectar in the depth of the tubular flower and the dragon’s mouth snaps shut behind it. Not to worry, though, the bumblebee is unharmed and soon pushes its way back out, coated in pollen, having drunk its fill of sweet nectar.
Sphinx moths, with their long proboscis and, in the New World, long-beaked hummingbirds, also share the snapdragon’s bounty.
Note that snapdragon flowers are fragrant, but that is most noticeable either close up or when there are mass plantings.
A Brief History
Snapdragons have been in cultivation for a long time. They were known to the Ancient Greeks, at least as medicinal plants, while the Romans grew them as cut flowers. In Russia, their seeds were pressed for use as an edible oil. American president Thomas Jefferson is known to have grown them in his garden in the late 1770s while Charles Darwin studied their hybridization nearly a century later.
By the Victorian era, snapdragons were already popular bedding plants and that has continued to this day. Their heyday was probably the mid twentieth century when they seemed to be found in every garden. Many of today’s gardeners remember them fondly as one of Grandma’s favorite plants.
A Wide Variety
The original wild snapdragon bears upright spikes of pink to purple flowers with orange to yellow on the lower lip over shiny dark green fairly narrow leaves. Flowers open starting at the base of the spike and work their way upwards.
In culture, all sorts of varieties have been developed, including a nearly full range of colors—red, orange, pink, white, purple, etc. (only true blue is absent!)—as well as varieties with peloric (open-faced) flowers, almost like mini-hollyhocks, and azalea-type (double) blooms. Some have dark purple or variegated leaves or bicolor flowers.
Sizes include dwarf varieties (6–10 inches/15–25 cm high, 10–12 inches/25–30 cm wide), medium varieties (16–24 inches/40–60 cm tall, 12–18 inches/30–45 cm wide) and tall varieties (24–30 inches/60–75 cm tall, 14–16 inches/35–45 cm wide). Dwarf types are currently the most popular and are used as edging plants and in containers. Taller varieties are popular as cut flowers and are, in fact, widely grown year round in greenhouses for that purpose, but also in outdoor gardens. There are even trailing varieties for containers, like ‘Candy Showers’.
Snapdragons are not true annuals. In mild climates, zones 7 to 10, they’re perennials, although not particularly long-lived ones. However, they’re almost always grown as annuals.
In cold climates, they’re sown indoors in late February to early April and planted out fairly early in the spring, before most other annuals, while the air is still cool, but when there is little danger of severe frost. They’ll breeze right through light frosts though. Their blooming may slow down in the heat of the summer, but will pick up again in the fall.
In climates where summers are torrid but winters are mild, like Florida, snapdragons don’t do very well as summer annuals (endless weeks of heat can weaken or even kill them) and they’re instead often sown in late fall for late winter to early spring bloom.
If you start your own from seed, you’ll find them easy to grow. Sow the seeds without covering them, as they need light to germinate. You don’t even need particularly warm conditions: 60–70 °F/15–21 °C is quite adequate. Just sow the seeds about 8 weeks before the last frost date and keep them at least slightly moist. They should sprout in about 10 to 20 days. Pinch the seedlings when they have six true leaves to stimulate better branching.
Or skip growing them from seed and buy trays of already-started snapdragons in early spring.
Plant out in full sun to partial shade (partial shade is best where summers are hot) in rich, well-drained soil. Water carefully, moistening the soil but not the leaves or flowers, to help prevent disease. Taller varieties may need staking.
Cut off flower spikes when they only have a flower or two left at the tip and are looking gangly: this will help stimulate rebloom, although it would be wise to let at least one plant go to seed either so they can self-sow or you can harvest seeds for the following year.
Insects and Diseases
Where snapdragons are happy, they rarely have serious insect and disease problems nor are they usually bothered by deer or rabbits. However snapdragon rust (Puccinia antirrhini), a fungus causing yellow leaf spots on the top of the leaf (they’re brown underneath) and often serious leaf loss, can be a problem where snapdragons overwinter. It’s one of the reasons they’re usually grown as annuals, since if you cut them off at the end of one season and start new plants from seed the next, there is little chance of disease, carried on the leaves, can survive (it is not borne on seeds).
There are rust-resistant strains available, but usually good maintenance suffices.
Snapdragons: so much more than Grandma’s back-of-the border cut flower. Try them this summer and see!