Mask flower is a genus of annual ornamental flowering plants and shrubs in the Scrophulariaceae, or figwort, family. It is native to Central America and western South America from Mexico and as far south as Chile and Peru; two species are also native to South Africa This plant gets its name from its unique, mask-like appearance. It may be included in flower gardens or grown in containers indoors or out. It is generally easy to grow and does not require a great deal of maintenance.
Also known as Alonsoa, mask flower grows in U.S. Department of Agriculture Hardiness Zones 9-11. This means that it will not tolerate temperatures below 25° Fahrenheit (-3.8° Celsius). All 12 species of this genus grow best in full sun and prefer to grow in rich, well-drained soil. Most species thrive when they get south facing light in the northern hemisphere and north facing light in the southern hemisphere.
Plants in this genus grow to be between 18 to 36 inches (45-90 cm) tall. From spring through fall, mask flower blooms repeatedly and often profusely. Depending on the particular species, its blooms can be red, orange, white, yellow, blue, or orange-red in color. Flower size depends on the species. Its grass-green, oval foliage is between 3/4 to 1 inch (20-30 mm) long and has simple, sharply-toothed edges.
Propagation of mask flower is straightforward. Seeds can be sewn directly into the ground in fall or can be started indoors prior to the last frost in spring. When growing this flower in a garden bed, plants in this genus should be spaced about 12 to 18 inches (30-45 cm) apart. The Alonsoa acutifolia species blooms profusely and can be used as a focal point in landscaping and attract birds, bees, and butterflies into the garden. Some species, such as Alonsoa myrtifolia, make excellent potted plants, although grow well when planted in a larger container or directly in the ground.
Mask flower is resistant to most diseases and is not bothered by most common plant pests. In fact, Alonsoa meridonalis attracts insects such as syrphid or honeyflies, which will help keep other unwelcome bugs away. If the plant does become infested with insects, picking them off by hand and then spraying with an insecticidal soap will usually take care of the problem before too much damage is done. If shrub species become lanky, they can be pruned without any ill effects.
