Botanically speaking, violas, pansies, and almost all violets are perennials belonging to the genus Viola. However, violas and pansies are usually treated as annuals, invaluable for winter and spring bloom in mild-winter areas, for spring-through-summer color in colder climates. Typically used for mass color in borders and edgings, as covers for spring-flowering bulbs, and in containers. Violets are more often used as woodland or rock garden plants.
Violas and pansies take sun or partial shade; violets grow in part or full shade (except as noted), but most are natives of deciduous forests and bloom best with at least some sun during the flowering season.
Almost all violets have two kinds of flowers: normal, conspicuous ones that rise above the foliage and may be pollinated and set seed, and short-stemmed, inconspicuous cleistogamous (Greek for “closed spouse”) flowers that set copious seed without pollination and produce offspring identical to the parent. Many violets also spread by aboveground runners. Some reproduce so freely they can crowd out other small plants.
Violas and pansies have such complex ancestries that many botanists are unwilling to assign them to species, preferring to list them by variety name. However, it will avoid confusion if we retain these plants under their former names, invalid though they now may be.
In cold-winter climates, set out nursery plants of pansies and violas in spring for summer bloom; in mild climates, plant in autumn for winter-to-spring (or longer) bloom. Or start from seed: in cold climates, sow in mid- to late summer and overwinter seedlings in cold frame until spring; or sow indoors in winter, plant in spring. In mild-winter areas, sow in mid- to late summer, plant out in fall. To prolong bloom, pick flowers (with some foliage) regularly and remove faded blooms before they set seed. In hot areas, plants get ragged by midsummer and should be removed.
The violet of song and story. Grows to 8 in. high and 1/2 ft. wide. In cool, mild climates, can spread widely by seeds and runners, possibly becoming a pest. Dark green, heart-shaped, 2 1/2-in.-long leaves with toothed margins. Fragrant, short-spurred flowers 3/4 in. or wider in deep violet, bluish rose, or white. Tolerates full sun in cool-summer areas. For better spring display, remove runners and shear rank growth in late fall, then apply a complete fertilizer in earliest spring.
From the Mediterranean and western Asia. Grows to 2–3 ft. high and wide, with downy, heart-shape...
Native from Vermont to Alabama, west to North Dakota, Wyoming, and New Mexico. This stout-stemmed plan...
From southern Europe. Grows to 8–10 in. high, spreading fast by underground rootstocks and flesh...