Sweet Rocket - Hesperis Matronalis
This hardy biennial features fragrant flowers in pink, purple, mauve or white, the most sweet-smelling in the evening. It grows to a height of 60-90cm, and is a favourite for butterflies.
Sow direct from spring onwards. When seedlings are large enough to handle, prick off into pots or boxes and grow on. Gradually harden off and plant out.