Growing Green: Snapdragons for Your Garden
The hot humid days of summer have arrived, and with them, that childhood favorite, Antirrhinum majus, the ubiquitous snapdragon. Hand a child one of these flowers, and the first thing they do is pinch the sides to move the petal “jaw”. Not many flowers evoke such whimsical childhood memories like the snapdragon. These prolific annuals come in every color but blue, and start easily from seed.
Snapdragons are most productive in full sun (6-8 hours a day), but can tolerate some light shade. Plant in well drained soil, and amend sandy or heavy soils with organic material: compost or peat moss. The root system is shallow and fine, and can be easily damaged by cultivation. Surround plants with a deep layer of organic mulch to conserve soil moisture, prevent weeds and keep the root system cool. Snapdragons need frequent watering for the first couple of weeks after transplanting (daily watering in sandy soils). Once established, water when the top 1” of soil feels dry to the touch. Snapdragons perform best in cool weather, and most cultivars can tolerate frost and an occasional light freeze.
There are many distinctive types of snaps for different uses in your garden design. Dwarf plants have a dense, bushy habit producing numerous flower spikes. They grow just 6 to 15 inches tall and are perfect plants for use in a low border or containers. Mid-sized varieties grow 15 to 30 inches tall and are used in borders (either alone or with other annuals) and as cut flowers. Tall varieties will grow 30 to 48 inches in height. They make a wonderful plant for the back of the border as well as for cut flowers.
For cut flowers, choose tall varieties and plant at 4” spacing. These tall snapdragons need support to grow straight. The tips of snaps will always grow vertically, and wind, rain and the weight of the plant itself can cause twisted growth in unsupported plants. These curves will remain, even if the plant is later straightened vertically. Use stakes, peony rings or horizontally staked mesh netting to support plants as they grow. Mesh sizes of 4”x4” or 6”x6” are most commonly used. Two levels of support netting are typically used. Place the first netting 4”-6” above the ground, and the second level of netting 6” above the first level. Raise the second level as the stems strengthen.
Some new and unusual varieties of snaps have entered the market in recent years. Butterfly snapdragons are covered with double blooms, reminiscent of delphinium flowers. These dense floral spikes are quite fragrant, and are stunning in cut bouquets. Look for cultivars like ‘Madame Butterfly’ or ‘Chantilly’. Popular tall varieties include ‘Rocket’, ‘Snappy Tongue’ & ‘Animation’. For the front of your garden bed, look for ‘Liberty’, ‘Tom Thumb’ and ‘Floral Carpet’. Trailing varieties, for the “spiller” in your container gardens, look for varieties like: ‘Cascadia’, ‘Luminaire’ and ‘Fruit Salad’.
Robin Trott is a Horticulture Educator with University of Minnesota Extension.