Snapdragon Types: Decoding Flower Shapes & Classifications

Are you baffled by the confusing world of snapdragons (Antirrhinum spp.)? Terms like butterfly snapdragon and Group II plant got you scratching your head? Fear not! This guide will demystify everything for you, so you can confidently stroll into the store and ask for the most beautiful Group IV, double-flowered, multicolored series they have. Let’s dive in!

But before we begin, take a moment to familiarize yourself with our snapdragon growing guide. Get ready to arrange your vases and envision your dream cottage garden, because we’re about to embark on this adventure together.

Flower Type

Snapdragons come in two types of flowers. The first is the familiar single-flower type, with a hinged jaw that opens like a mouth. The second type is the double flower, also known as a butterfly or azalea snapdragon.

Double snapdragon flowers resemble azaleas, with more abundant and flatter petals. Some say they even look like butterflies, hence the name. These double-flower types stay in bloom longer than the single-flower types. Classic examples of single-flower types are found in the Aroma series, while Bright Butterflies is a popular double-flower series.

Group Classification

Snapdragons are often classified based on their ideal growing season and flowering period, which are determined by temperature and daylight hours. Although not an official botanical system, this classification helps commercial and home gardeners choose the right plants.

Group I: Winter

Snapdragons in this group thrive in weak light and shorter winter days, particularly in Zone 7 or Zone 6 with some protection. They are shorter with small flower heads but quickly develop and start flowering early in the season. You can grow them in tunnels, under frost cloth, or in greenhouses. Admiral, Chantilly, and Alaska series flowers belong to Group I.

Group II: Early Spring

Plants in this group require brighter light and longer days than winter types but less than summer types. They are medium in height with medium-sized flowers. You can start growing them in tunnels or under frost cloth in early spring. Cinderella, Costa, and ‘Little Darling’ are popular series and cultivars of Group II.

Group III: Late Fall

Similar to early spring types, Group III snapdragons grow best during fall and tend to bloom later in the growing season. Animation and Apollo series plants can be found in this group.

Group IV: Summer

Plants in Group IV need the most light and longest days of all cultivars. They are tall and require a longer time to mature, blooming later in the year. It’s not recommended to use tunnels or frost cloth to extend the growing season for these types, as they thrive in bright, intense summer light. Rocket and Opus series flowers fall into Group IV. If your growing season isn’t long enough, consider growing other options instead.

By selecting Antirrhinum types from different groups, you can enjoy a continuous display of colors throughout the changing seasons, provided you have the right growing conditions.

Height and Growth Habit

Snapdragons are categorized based on their mature height. The following groupings can be found in plant descriptions:

  • Tall: 24 to 36 inches
  • Intermediate: 12 to 24 inches
  • Short: 9 to 12 inches
  • Dwarf: 4 to 9 inches

For tall types, it’s beneficial to provide cages or supports if you plan to use them for cut-flower displays. Admiral, Chantilly, and Liberty series are known for being tall types. Dwarf varieties are perfect for containers and are sometimes referred to as miniatures. Popular series include Tahiti, Bells, Floral Showers, and Montego. While most snapdragons have an erect growth habit, trailing types like Chandelier, Lampion, and Luminaire series are also available.

Series and Cultivars

Many snapdragon cultivars are trademarked and sold in what is known as “series.” These series consist of identical flowers varying only in color. They share the same height and growing requirements. However, the term “series” should not be confused with the botanical designation, as it is mainly a marketing term. Some well-known series are Floral Carpet, Princess, Double Azalea, Opus, and Chimes.

In addition to series, you may also come across heirloom and hybrid cultivars that are not part of a series. ‘Black Prince’ is a popular heirloom cultivar with deep purple flowers and dark green foliage.

For more information on our favorite series and cultivars, as well as where to buy them, check out our detailed guide on the best snapdragon series and cultivars to grow at home.

Now armed with this newfound knowledge, you can confidently navigate the world of snapdragons and choose the perfect ones for your garden. Happy growing!