A big, blousy, rounded shrub packed with mid-green leaves, flowering in blue and pink in July and August. If you grow it on acid ground, there will be more lilac flowers, while alkaline soil generates pink. Shelter from cold, drying winds is essential as this can spoil the foliage and flowers. To promote plenty of fresh, new, vigorous growth on established plants, cut back hard in early spring. Prune out from one-third to one-quarter of last year's growth to the base each year to encourage the plant to produce new shoots.

True to its name, the flowers are pure white, being set off by the clear green foliage. Keep deadheading and they'll last right through summer, into autumn. Seed can be sown in late summer or early autumn, pots being kept in a cold frame over winter, or wait until early spring. The plants look best when planted in clusters in a cottage garden or informal border, making a strong contrast with rich reds and blues.

Ideal in cottage gardens packed with old-fashioned plants, 'Mrs Sinkins' (named after Catherine Sinkins, who raised it and died in 1917) has attractive, ragged petals with a pale green centre. It is best grown right at the front of a border where you can fully appreciate its gorgeous sweet scent. It blends nicely with other old-fashioned, subtly-coloured pinks such as the white 'Dad's Favourite' with maroon lacing, but for stronger contrasts go for the bolder, modern, repeat-flowering, weakly-scented kind like the red and white 'Alice'. If you haven't got a flower bed in full sun with quick-draining soil, you can grow pinks in troughs or old sinks where you can guarantee the right conditions.

This attractive perennial looks wonderful when covered in flower from early summer. The pale, lavender-blue flowers perfectly complement the hairy, scalloped and wrinkled, silvery, blue-green leaves. From afar the flowers appear as a haze of blue. Nepeta has a rather lax form and will spread itself to cover its allotted space. Plant it at the front of the border, edging a path, so that when you brush past it you will catch the full scent from its aromatic leaves. Cats love Nepeta and tend to roll around on it, flattening the plant even more. Divide it in spring or in autumn. The Royal Horticultural Society have given it their prestigious Award of Garden Merit.

Achilleas are traditional border flowers valued for their feathery foliage and striking flat, circular heads of flowers throughout the main summer season. They team well with other perennial flowers and are a vital ingredient of a traditional herbaceous border. They are also at home in island beds, cottage gardens and other perennial planting schemes. The variety 'Coronation Gold' has silvery foliage and flowers of gleaming golden yellow that are attractive to bees. The blooms also are good for cutting or drying. Plants spread slowly into fat clumps without becoming invasive. It has been given an Award of Garden Merit (AGM), which is for plants of outstanding excellence.