Growing Viola
Latin Name Pronunciation: vie-oh' luh
Violas
Violas look like mini Pansies in simpler dress and their sweet “faces” are no less charming. They’re more heat tolerant and floriferous than Pansies and brave spring gales with aplomb. These rhizomatous, spreading perennials of variable hardiness sometimes remain evergreen. Charming little Johnny-jump-ups (V. tricolor) often act like annuals, blooming throughout spring and summer, delightfully self-sowing, after which they fade away. On the other hand, we grow Viola cornuta cultivars and hybrids because they thrive in temperate zone gardens for years. Lovely in containers, Violas add pizzazz to the spring garden, combining beautifully with spring bulbs or cool-weather blooming Snapdragons and Calendulas.
Light: Full sun is preferred in cooler areas; part shade, preferably in the afternoon, in hotter zones within their range.
Watering: Violas have moderate water needs and bloom best with regular watering. Avoid overhead irrigation.
Fertilizer: Compost is always welcome. A light application of balanced, slow-release fertilizer worked into the soil in spring and again in late summer encourages plants to keep blooming.
Soil: Humus-rich soil that retains moisture, preferably on the slightly acidic side. A thin mulch layer of organic material such as shredded bark or pine needles is beneficial to preserve soil moisture and protect shallow roots from excessive heat or cold.
Pests/Diseases: Fungal leaf diseases are possible; avoid overhead irrigation.
Seasonal Care: Pinch spent flowers to encourage ongoing blooms. Once weather gets hot or plants get leggy, cut plants back to the first set of leaves and fertilize to revive. In the hottest zones, where Violas are grown as annuals because they can’t take the heat, pull up and discard plants when they lose their good looks. Plants grown in containers can be moved to more shade if they sulk in summer and overwintered in an unheated shed or garage.
Violets
Violets are hardy, long-lasting clump-forming perennials delightful in woodland gardens. Different species bear small, mostly spring-blooming purple, blue, white or yellow flowers, some freckled or splotched, with two petals facing upward and three facing down. Later blooms hidden under the foliage self-pollinate without opening. North America hosts about 200 native species, which are important nectar plants for pollinators and the host plant for Fritillary butterflies. Winter hardiness and heat tolerance varies between species, some being hardy to Zone 3, some with heat tolerance to Zones 8 or 9. Plant in the woodland garden, along a path, as a groundcover under shrubs, or in a rock garden.
Light: Most prefer dappled or part shade, especially in hotter climates. Some species, particularly Viola pedata tolerate or prefer full sun.
Watering: Even moisture for many Violet species, dry to medium moisture for Viola pedata.
Fertilizer: An annual application of compost is beneficial. To increase plant vigor, if desired, work a balanced slow-release granular fertilizer into the soil with a very light hand in spring. Do not fertilize Viola pedata.
Soil: Many Violets are woodland species that prefer moist, humus-rich, well-drained soils. Viola pedata, native to gravelly or sandy areas, prefers poor soil with sharp drainage such as in rock gardens.
Pests/Diseases: Generally pest- and disease-resistant. Some species are susceptible to crown rot in poorly drained soils.
Seasonal Care: Violets require little care.
