A wallflower is a plant in the genus Erysimum, a medium-sized botanical genus placed in the mustard family. The common name, a reference to the fact that these plants often grow in loose mortar in cracks on walls, dates to the 1500s. Members of this genus are distributed all over the world in a variety of climates, and several species are cultivated as ornamentals in gardens. People who would like to grow wallflowers can find seeds and seedlings at nurseries or through catalogs. It is also possible to obtain them from other gardeners with established plants.
Members of the Erysimum genus are variable in appearance. Wallflowers bloom in colors like white, purple, or yellow, with the flowers appearing in clusters like those of other members of the mustard family. The foliage is usually small and simple and members of this genus tend to grow low to the ground, with an erect, slightly leggy growth habit. Some wallflower species are annuals, while others grow perennially in the right climate.
Like many members of the mustard family, the wallflower is adapted to grow in adverse conditions. The plants prefer full to partial sun and will grow in coarse soil with low nutrients. The tendency to grow in mortar and cracks is illustrative of the fact that these plants will grow in very harsh conditions. Some species provide a source of nectar for butterflies and are of interest to bees and other insects, and wallflower foliage is also edible for animals like deer and rabbits.
In the garden, wallflowers can be grown as specimen or massed plantings. They are suitable for low water gardening, as well as gardening in areas with poor soil and salty conditions. The plants will reseed themselves if they are annuals, and often thrive on relatively minimal care. The colorful blooms and upright stems can add color to the garden in areas where other plants may have difficulty growing. Wallflowers are also suitable for container gardening and can be grown in hanging baskets and window boxes.
The slang term “wallflower” in reference to women without dance partners dates to the 1800s. It appears to be a reference to the plants known as wallflowers, and their tendency to cling to walls and fences rather than growing out in the open. Generically, this common name is sometimes applied to other plant genera and species with a fondness for growing in, on, or along walls.