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Growing Snapdragons

Amusing “Snappable” Blooms with Animated Shades

by Frances Santos

Growing SnapdragonsSnapdragons (antirrhinum majus) are fascinating flowers because of their velvety, open-faced flowers with single or double petals. They often come in vibrant shades of burgundy, red, white, yellow orange, pink, bronze, and many varieties have blending colors (except true blue).

The beautiful whorl of blooms sits on top of slender stalks. Kids will love creating the “dragon mouth” as individual blossoms have “mouth” that snap open just like puppets when pressed at the sides.

Snapdragons are native to North Africa and Spain, but the common Snapdragon has grown widely in temperate areas throughout southeast Canada and United States. They belong to Scrophulariaceae family, and often called as Toad’s Mouth, Lion’s Mouth or Dog’s Mouth.

Snapdragons are perennials, meaning they have a lifecycle of more than three years. But in cold-weather regions, they are grown as an annual flower. Snapdragons tolerate cool weather so you can plant them to brighten up your garden during winter.

Dwarf varieties that grow 10 to 18 inches tall make beautiful borders and edgings, while taller varieties can be planted at the back of your floral border. They also make nice cut flowers. But take caution when handling snapdragons as all parts are poisonous, if ingested.

Snapdragons Propagation

Snapdragons are propagated by seeds or cuttings. Cuttings root readily, while as for seeds, it’s best to start them in September. The secret to growing snapdragons that are economical, strong and attractive is cool temperatures.

How to Grow Snapdragons

Plant snapdragon seeds indoors 6 to 8 weeks before the last frost in your area then transplant them later on outdoors.  But it is recommended to let the young plants adapt to outdoor conditions gradually for a week before transplanting them in your garden.

Chill/freeze the seeds for 48 hours before sowing to get faster germination process. The seeds require light to germinate so just scatter them on the soil surface and lightly press down to secure them. Use rich, well-drained soil in organic matter. Place the seeds in a well-lit location, preferably near your windowsill. Getting full sun and good ventilation aids snapdragons to develop sturdy stems. Seeds germinate in about 10 to 14 days at 21°C. Keep the soil moist, but not wet.

Transplant the seeds outdoors when the soil has warmed. Take note that the roots must enable to grasp the plug mass together without difficulty and the plant must already develop 2 to 3 sets of true leaves. Again, choose a sunny location with rich, fertile and well-drained soil. Mix organic matter into the soil to improve its quality and richness. When transplanting your snapdragons, follow a well-timed method to evade stunting growth. In general, space tall Snapdragon varieties 30cm apart and shorter varieties 15 to 25cm apart.

For bedding snapdragons, it is most beneficial to re-plant them in 4-inch pots, 18 to 36 cell flats, or in clusters of 3 to 5 plants in a gallon container. But for trailing snaps, re-plant snapdragons in 2-inch pots or in 6-inch pot if transplanted in pairs. You may also plant snapdragons in hanging basket. A 10-inch hanging basket can actually accommodate 4-5 cuttings. Water the plants often for the first few weeks, and then reduce watering to once a week or when the soil feels dry. Do not overwater the plants as this can kill them. Once established, Snapdragons generally live well and healthy without too much pampering.

Snapdragons Care

Providing extra care promotes optimum growth. Here are some good tips:

  1. The recommended soil pH when growing snapdragons is 5.5 to 6.2. Use moderate initial fertilizer. For trailing snaps, keep constant fertilizer levels because low fertilizer levels can hamper branching.
  2. Feed snapdragons with 150 to 200 parts per million nitrogen twice every week. Alternate 20-10-20 and 15-0-15 fertilizer formulations. As soon as the flower shoots begin to stretch, reduce the formulations in order to lengthen snapdragon’s postharvest life.
  3. Take note that applying fertilizer with excessive nitrogen concentration under low light conditions may cause over production of foliage. The same goes for overwatering under low light conditions.
  4. Pinch back tips of young plants when they are 2 to 4 inches tall to encourage branching. This will give you more abundant flower spikes and bushier plants.
  5. Deadheading or removing spent blooms will also promote showy new blooms and longer flower periods. Shape snapdragons by shearing the plants.
  6. Low light levels may cause stretching, decrease flowering and increase crop time. For best results, keep light levels at high range, preferably between 5,000 to 6,000 footcandles. Additionally, maintain daytime temperatures at 72 to 75 degrees F and night time temperatures at 60 degrees F or below.
  7. Use stakes to secure taller varieties from harsh winds and rains. Additionally, if a hard freeze is expected, make sure to cover the soil around the plants with mulch. Snapdragons will continuously reseed themselves year after year.

Troubleshooting High Soil pH

High pH may stunt plant growth or cause poor root growth and imbalanced development of seedlings. It may also cause boron deficiency and insufficient iron uptake due to interveinal chlorosis of undeveloped foliage. So what you could do to adjust high pH levels? Spray the plants with iron sulfate at 33 ounces/100 gallons of water.

Snapdragon Diseases

Watch out for a fungal disease called Snapdragon rust. This causes yellow swellings to appear on stems or leaves. Yellow spots also form on the upper leaf surface and rings of purple or dark brown powdery spores can be seen around the initial spots. This disease will dry up the infected plants due to rapid water loss, so infected plants must be stunted or killed.