Sweet Violets (Viola odorata) are an old perennial favourite. Tolerant of cold winters and warm summers, their colourful and highly scented blooms are a great addition to cottage style gardens. They form a green carpet and push up lovely purple flowers over early spring.
I. Appearance and Characteristics
Viola odorata is a species of flowering plant in the family Violaceae, native to Europe and Asia. This small hardy herbaceous perennial is commonly known as wood violet, sweet violet, English violet, common violet, florist’s violet, or garden violet. It has been introduced into the Americas and Australia.
The species can be found near the edges of forests or in clearings; it is also a common “uninvited guest” in shaded lawns or elsewhere in gardens.
Viola odorata can be distinguished by the following characteristics:
- the flowers are scented
- the flowers are normally either dark violet or white
- the leaves and flowers are all in a basal rosette
- the style is hooked (and does not end with a rounded appendage)
- the leaf-stalks have hairs which point downwards
- the plant spreads with stolons (above-ground shoots)
These perennial flowers mature at a height of 4–6 in (10–15 cm) and a spread of 8–24 in (20–61 cm).
II. How to Grow and Care
Sunlight
Sweet violet’s requirement for sunlight is moderate. Although it loves sunlight, sweet violet is also relatively shade-tolerant. Anyplace where there is sunshine in the daytime is suitable. Intense sunshine, as well as a relatively high temperature difference between day and night, helps to maintain its shape.
If sweet violet suffers from seriously insufficient sunlight for long, the stems will become thin, long, and floppy. Protecting it from strong direct sunlight in summer is also advised. It can be sunburned to death due to high temperature.
Temperature
Sweet violet is cold-resistant and moderately heat-resistant. Generally speaking, it flowers from spring to fall. Quantity of flowers may decrease in high temperatures. It can tolerate slight frost and snow cover in winter. If grown in a cold region, it should be kept warm in winter. In a word, it should be protected from high temperature and humidity in summer, and have less water in winter during its dormancy.
Watering
Sweet violet is native to humid forests and mountainous areas, so it is not drought-tolerant. However, excessive watering will lead to the decay and death of the plant. If it is planted in gardens, water according to the weather conditions only to keep the soil from excessive dryness. In pots, water thoroughly when the soil surface is dry.
Soil
Sweet violet likes moist, well-drained, air-permeable soil. A small amount of substrate, such as perlite, ceramsite, and vermiculite, can be added to the soil when planting.
Fertilizing
Common slow-release commercial compound fertilizers can be used for sweet violet. During the growth and bloom time, thin compound liquid fertilizer can be applied once every two weeks. For specific application methods, please refer to the product specifications of the compound fertilizers.
Planting Instructions
Although it is a perennial plant, sweet violet is usually replanted every year. Sow it from late fall to early spring of next year, and flowers will come in about two months after sowing. Try to choose a cool environment. Sprinkle seeds directly on the surface of the soil, and cover them with a thin layer of soil.
To sow indoors, wrap the seeds in a wet paper towel. Pack the paper-wrapped seeds into sealed bags or other containers and put them in the refrigerator or refrigerating chamber for 3-4 days to accelerate germination.
After the seedlings germinate, remove the top buds to facilitate the growth of lateral buds. This prevents seedlings from getting floppy and spindly, supports the plant shape, and increases the quantity of flowers. If the seedlings bloom early, early-blooming flowers can be removed so the plants accumulate energy to bloom more.
Propagation
If they are happy in their location, Sweet Violets will sow themselves and create a fragrant, flowery mat. Ants are also keen to carry the fruit of the plant around, meaning the sweet violets can crop up at unexpected locations all over the garden. The best way to achieve targeted propagation is through dividing large clumps or harvesting and sowing seeds. A word of caution: Not all varieties go to seed; some can only be propagated through cuttings. Moreover, lots of Sweet Violets cross-breed, which makes it extremely difficult to achieve pure variety propagation when there are several sweet variety species in the garden.
Pests and Diseases
When Sweet Violets are kept in a warm, dry place it is possible for spider mites to spread.
III. Viola odorata varieties
The sweet violet varieties differ not only in the colour of their flowers, but also in how big they grow, when they flower, and how intense their sweet fragrance is. Here are the most beautiful varieties of sweet violet:
- Viola odorata ‘Alba’: white sweet violet with delicate fragrance. The flowers of this 10 – 15 cm high variety bloom between March and May.
- Viola odorata ‘Coeur d’Alsace’: very vigorous sweet violet cultivar with graceful pink flowers. Plants grow up to 15 cm tall. The flowering period is between March and May.
- Viola odorata ‘Diana Groves’: sweet violet with rare, raspberry red color. Grows up to 10 cm tall. The flowering period is between April and May.
- Viola odorata ‘Donau’: this variety has exceptionally large, blue-violet flowers on long stems and a strong fragrance. The robust and vigorous sweet violet ‘Donau’ grows 10 – 15 cm tall and blooms between March and May.
- Viola odorata ‘Queen Charlotte’: has a strong fragrance and flowers twice, once in spring and again in late summer. The Viola odorata ‘Queen Charlotte’ has beautiful deep purple flowers and grows up to 15 cm tall. Also known as Viola odorata ‘Königin Charlotte’.
- Viola odorata ‘Madame Armandine Pages’: old French cultivar from 1900 with large, long-stemmed whitish pale pink flowers. The flowering period is from March to April.
- Viola odorata ‘Melanie’: sweet violet with large candy pink flowers. Blooms from March to April and reaches a height of 15-20 cm.
- Viola odorata ‘Orchid Pink’: this very early flowering variety blooms from February to March with large pale red-purple flowers with purple veining in the centre. It grows to a height of 20 – 25 cm.
- Viola odorata ‘Princesse de Galle’: slightly fragrant sweet violet hybrid with dark purple, very large, wide open flowers between March and April. The variety is strong-growing and grows up to 15 cm tall.
- Viola odorata ‘Reine de Neiges’: this sweet violet has white flowers with a blue tinge and was developed from the ‘Queen Charlotte’ variety. The strong-growing and healthy variety propagates well and also blooms twice a year like the mother variety.
- Viola odorata ‘Sulphurea’: sweet violet variety with rather weak growth and filigree, orange-yellow to sulphur-yellow flowers with purple tips. Flowers between March and May.
- Viola odorata ‘Wismar’: heritage sweet violet seedling from Wismar ca. 1895 with white-pink and purple flowers. This bright variety spreads very easily and grows 15 cm tall. Flowers from March to May.
IV. Uses and Benefits
- Ornamental uses
Sweet violet is highly prized for the heavenly scent that it produces. This late winter and early springtime bloomer adds an injection of color and interest to gardens looking lackluster after the winter season. It is versatile and can be used for underplanting, beds, and containers.
- Medicinal uses
As an ornamental and medicinal plant, Sweet Violet has been cultivated and used medicinally since the Middle Ages. V. odorata, along with others in the Violaceae family such as V. tricolor, has a long history of use in herbalism and folk medicine, particularly Iranian, Greco-Arab, Ayurvedic and Unani traditional health systems. Phytochemical studies have shown that V. odorata contains the alkaloid violin, about 30 cyclotides, triterpenoids (mostly as constituents of the essential oil), supporting long-held beliefs of its medicinal properties, that still have the need to be proven pharmacologycally.
In herbal medicine, V. odorata has been used for the treatment of whooping cough, headaches, migraine, insomnia, sore throat and epilepsy in children and adults, and clinical studies appear to confirm the safety and efficacy of V. odorata syrup in cough, insomnia and migraine treatments, and in treatment of pain, fever, cough, skin disorder, infection and inflammation.
One specific study indicates that V. odorata extract given as a preventative/prophylactic is as effective as using corticosteroids reactively to treat specific types of lung disease.
- Cosmetic uses
The sweet scent of this flower has proved popular, particularly in the late Victorian period, and has consequently been used in the production of many cosmetic fragrances and perfumes. The French are known for their violet syrup, most commonly made from an extract of violets. In the United States, this French violet syrup is used to make violet scones and marshmallows.
The scent of violet flowers is distinctive with only a few other flowers having a remotely similar odor. References to violets and the desirable nature of the fragrance go back to classical sources such as Pliny and Horace when the name “Ion” was in use to describe this flower from which the name of the distinctive chemical constituents of the flower, the ionones, is derived. In 1923, W.A. Poucher wrote that the flowers were widely cultivated both in Europe and the East for their fragrance, with both the flowers and leaves being separately collected and extracted for fragrance, and flowers also collected for use in confectionery galenical syrup and in the production of medicine.
There is some doubt as to whether the true extract of the violet flower is still used commercially in perfumes. It was still used in the early 20th century, but by the time Steffen Arctander was writing in the late 1950s and early 1960s, production had “almost disappeared”. Violet leaf absolute, however, remains widely used in modern perfumery.
