How to care for snapdragon perennials
Snapdragons (Antirrhinum) are flowers that produce erect stalks ranging from 15 to 91 cm (6 inches to 36 inches) in height. The stems bear the plant's blossoms, which appear in bronze, white, yellow and other colours depending on the variety. Snapdragons bloom in full sun from spring until the autumn.
They can withstand average minimum temperatures between -18 to -1 degrees C (0F to 30F).
Grow snapdragons under full sun in soil rich in organic matter. Incorporate 5 cm (2 inches) of compost or manure into the ground before planting the flowers. The amendment not only enriches the soil, it also separates its particles for improved air and water circulation underground.
Place a garden hose 5 cm (2 inches) from the base of the snapdragon. Use it to apply water straight into the ground, keeping the foliage and blossoms dry. Snapdragons are susceptible to rust, a fungal disease that quickly spreads in wet environments. Keep the soil consistently moist.
Cut the stalks to five nodes from the ground after the first series of flowers fade. Feed the snapdragon a general fertiliser with equal percentages of nitrogen, phosphorous and potassium as soon as you notice another flush of flower buds forming. Apply the fertiliser brand you select according to the manufacturer's instructions.
Tie tall stalks that sway in the wind to stakes to prevent breakage. Use soft cloth to fasten them loosely to the support.
Build a 5 cm (2 inch) thick layer of mulch around the snapdragon plants to suppress weeds and slow evaporation. Use wood chips, shredded bark or grass clippings, for example.
Refill the mulch pile to take it back to a depth of 5 to 7.5 cm (2 to 3 inches) in early autumn, if necessary. Place the material 2.5 to 5 cm (1 to 2 inches) away from the snapdragon's stem. In winter, the mulch insulates the roots from fluctuating temperatures. Rake the mulch and discard it in the spring to prevent potential over-wintering pests and disease organisms from transferring to the plant. Build a new ring around the snapdragon with fresh mulch.