Buddleia (The butterfly bush)
Very easy to grow in almost any soil. Different varieties will flower in pink, red, purple, and white. Usually in bloom through July and August. These shrubs need pruning well in Spring as they can grow 5′ to 8′ from the ground in a single season.
Verbena Bonariensis
Stems up to a metre tall support heads of lavender flowers from August to October. Easy to grow from seed, plant March-April in well-drained soil. Can provide useful height at the back of a border. Only half hardy so can be a short lived perennial.
Lavender
Flowers are lilac-blue in color and grow on spikes through the summer. Plants can be used for edging beds or grown to form an attractive, low-growing hedge. It will thrive in a sunny, sheltered position in well-drained soil. Lavender should be planted in April or May and pruned back to encourage bushy growth.
Perennial Wallflower (Bowles Mauve)
Produces a profusion of sweet-scented purple flowers from April all through the summer. Wallflowers make great bedding plants and will grow well in full sun or light shade. Plant in well drained soil.
Marjoram (Oregano)
A perennial herb, growing from 20 to 80 cm tall. White, pink or purple flowers grow on spikes from June to September. A good edging plant and useful ground cover, requiring little maintenance. The smaller varieties also do well in rock and alpine gardens.