Agastache ‘Black Adder’ (hyssop) £7.99
Position: full sun Soil: well-drained, fertile soil Rate of growth: average Flowering period: July to October Hardiness: hardy (borderline) Hyssops are great for adding height to a border, with whorls of long-lasting, tiny flowers arranged like a bottlebrush and pointed, aromatic fresh green leaves that are attractive to butterflies. They are short-lived though, and may need replacing every few years, especially after a cold or wet winter. ‘Black Adder’ has smoky, violet flowers on long spires from July to October. Try it as part of a Mediterranean scheme or in a sunny, well-drained border among ornamental grasses. Garden care: Don’t cut back the faded flower-stems until early spring, as they provide interest in the winter months. Lift and divide congested colonies in spring.

Agastache ‘Painted Lady’ (giant hyssop) £7.99
Position: full sun Soil: well-drained, fertile soil Rate of growth: average Flowering period: July to October Flower colour: pinkish-orange Hardiness: half hardy Spikes of beautiful, tubular pinkish-orange flowers appear from July to October above the aromatic, grey-green leaves. This new upright, perennial is perfect for the middle of a sheltered, sunny border. An excellent companion for grey or silver foliage plants, the long-lasting flowers are highly attractive to bees. Garden care: Avoid the temptation to cut back the faded flower-stems in autumn since they provide interest in the winter months. Lift and divide congested colonies in spring.

Agastache ‘Black Adder’ (hyssop) £5.99
Position: full sun Soil: well-drained, fertile soil Rate of growth: average Flowering period: July to October Hardiness: hardy (borderline) Hyssops are great for adding height to a border, with whorls of long-lasting, tiny flowers arranged like a bottlebrush, and pointed, aromatic fresh green leaves that are attractive to butterflies. They are short-lived though, and may need replacing every few years, especially after a cold or wet winter. ‘Black Adder’ has smoky, violet flowers on long spires from July to October. Try it as part of a Mediterranean scheme or in a sunny, well-drained border among ornamental grasses. Garden care: Don’t cut back the faded flower-stems until early spring, as they provide interest in the winter months. Lift and divide congested colonies in spring.

Agastache ‘Blue Fortune’ (Mexican giant hyssop) £4.99
Position: full sun Soil: well-drained, fertile soil Rate of growth: average Flowering period: July to October Hardiness: hardy (borderline) Hyssops are great for adding vertical accents to a border, with whorls of long-lasting, tiny flowers arranged like a bottlebrush and pointed, aromatic fresh green leaves that are attractive to butterflies and bees. They are short-lived though, and may need replacing every few years, especially after a cold or wet winter. Blue Fortune has loose spires of lilac-blue flowers from July to October and peppermint-scented leaves. This upright, bushy perennial is perfect for the middle of a sheltered, sunny border. Try it as part of a Mediterranean scheme, with grey-leaved plants, or among ornamental grasses. Garden care: Don’t cut back the faded flower-stems in until early spring, as they provide interest in the winter months. Lift and divide congested colonies in spring.