Linaria maroccana aka Annual Toadflax

Linaria maroccana, or annual toadflax, is native to Morocco. It belongs to the plantain family, Plantaginaceae. This cool-season annual grows upright and branches into several stems. It has spread beyond gardens in parts of Canada and the United States. It also occurs in Spain, France, and Britain. Its pace of growth is moderate.

Plants reach about 0.75–1.5 feet [0.23–0.46 metres] tall in gardens. The RHS gives an upper height of 1.6 feet [0.5 metres]. Spread varies between the sources. NC State gives 0.5–0.75 feet [0.15–0.23 metres]. The RHS lists a narrower spread of 0.33 feet [0.1 metres]. The green leaves are narrow, simple, and hairless. They reach about 0.125 feet [0.038 metres] long. Leaves may sit opposite each other, alternate, or form whorls. The stems have no scent.

Small flowers grow in upright racemes at the stem tips. Each bloom has two lips and looks like a small snapdragon. A long nectar spur extends behind the flower. Purple-violet blooms can have a yellow patch on the lower lip. The RHS also records pink and white flowers. Flowering runs from April through June in the American sources. The RHS describes summer bloom under UK conditions. Dry capsules follow the flowers and split open when ripe.

Give this plant full sun and soil that drains well. It suits sandy or loamy soil with moderate fertility. It accepts acid, neutral, and alkaline conditions. Steady moisture supports growth, though NC State also lists drought resistance. Afternoon shade may help prolong bloom where summers turn hot. Heat can stop flowering and cause plants to fade. Sow seed where plants will grow in early spring. Late-summer sowing can provide flowers in fall. The RHS rates it H6; American sources list USDA zones 2–11.

Use toadflax in beds, borders, meadows, or cottage gardens. It also suits pots, baskets, and window boxes. Deer resistance adds to its garden value. Cutting plants back after the first flowers can encourage more bloom. Cutting back after flowering can also limit self-seeding. Plants can seed themselves where conditions suit them. Serious pest problems are uncommon, but aphids may appear. Powdery mildew can also affect the leaves.