Hesperis matronalis, Purple-Violet.

In spring, Dame’s Rocket lights up the woodland edges with her blossoms, providing nectar for hummingbirds, moths and butterflies, and fragrance for the soul.
Dames Rocket was the favorite flower of Marie Antoinette. The genus name Hesperis is Greek for evening, a reference to this plant's aroma becoming ever more conspicuous towards evening. The fragrance is as sweet as a violet's. The night-scented stock is a close relative.

The plants typically produce only a low-lying rosette their first year, in subsequent years, Dame's Rocket shoots up quickly in spring and enters full bloom by May.
They are excellent for naturalising on slopes and in woodland areas and will look good in a border especially in an informal cottage garden and they are very attractive to wildlife.

Sowing: Sow in late spring to early summer. (March to July)
Seeds can be sown directly where they are to flower in early summer, after all risk of frost has passed, or started early indoors or under glass.

Sowing Indoors:
Sow seeds at 20-25°C (68-77°F) on the surface of a peaty soil.
Do not cover or exclude light as they need light to germinate. Keep moist and do not let your seeds dry out once planted. They will usually germinate in 3 to 4 weeks.
Prick out each seedling as it becomes large enough to handle, transplant into 7.5cm (3in) pots or trays. Gradually acclimatise to outdoor conditions for 10-15days before planting out after all risk of frost.

Direct Sowing:
Sow thinly, 6mm (1/4in) deep in small clumps or shallow drills. Sow 30cm (12in) apart in well-cultivated soil which has been raked to a fine tilth. Water ground regularly, especially in dry periods.
When large enough to handle, thin out seedlings until they are finally 30cm (12in) apart in spring. Light spring frosts will not harm the plants.

Cultivation:
If grown in shady areas, the tall plants will lean toward the sun and may need staking. Aphids like this plant, but can be knocked off with a strong blast of water from the garden hose.
Control excessive seed production by deadheading after blooming. This also encourages a second bloom period. In the Autumn, leave a few plants to die down and self seed. Others can be pulled up and composted

Plant Uses:
Cottage/Informal Garden, Wildflower Gardens or Wildlife Gardens. Dappled Shade / Woodland Garden; Sunny Edge; Hedgerow
In Europe, Dame's Rocket is host to the caterpillars of several butterfly species, including the Orange tip and Cabbage White; and moths such as Plutella porrectella. (Don’t plant near to your cabbages!)

Origin:
Dame’s Rocket is native to the Mediterranean region and central Asia, but because of its value as an ornamental, it was introduced to European gardens from where it escaped to the wild, at home in rich shady soil.
The plant is often confused with look-alike native phlox species in North America, but they can be easily identified by their flowers, which have four rather than a phlox's five petals and phlox blooms much later in the year.

Nomenclature:
Its genus name Hesperis is derived from the Latin hesperius meaning 'of the West' or 'of the evening', possibly because it releases its sweet and spicy clove-like scent at nightfall.
Several of the common names by which it is known - Dames’s Rocket, Dame’s Violet and Mother-of-the-Evening all relate to women, alluding its species name matronalis: pertaining to the Roman festival of the matrons.
In The Herbal or General History of Plants by John Gerard (first published in London in 1597) it is listed under the name Dames Violets or Queens Gillofloures, where he remarked that it was grown in gardens 'for the beauty of their floures' and 'The distilled water of the floures hereof is counted to be a most effectuall thing to procure a sweat,' implying that it was used to help break a fever.
The common name of rocket is derived from the French roquette, or what we know today as arugula.

Folklore:
The folklore surrounding this one is both positive and negative. Some sources say it is a symbol of woman’s independence. And other folklorists, noting the strong cinnamon fragrance which is more noticeable in the evening than during the daytime, mention it as a 'flower of deceit.'