Easy-to-grow achilleas

Ideal for giving the garden a vibrant boost in midsummer, achilleas are a great option to keep the interest going for months, says Graham Rice, as he reveals some of the best

- Graham Rice,

A CHILLEAS are easy to grow and invaluable in the summer border, with a range of flower colours including some that change spectacularly as they fade.

These tough, exceptionally cold-hardy, sun-loving perennials, commonly known as yarrow, first develop a mound of finely dissected, prettily feathered aromatic leaves, in dark green, greygreen or grey.

Achilleas grow best in a sunny site in well-drained fertile soil, and established plants will take drought. Some make tight clumps, some spread more strongly and may be a nuisance, although achilleas are not deep rooted so their spread is easily limited. If not deadheaded, unwanted poor-quality self-sown seedlings will usually appear.

Daisy-like flowers

From late spring to autumn, flat or slightly domed heads of up to 300 small daisy-like flowers are carried on upright stems reaching 16in-5ft (40cm-1.5m) in height. In rich soils the plants may need discreet support from canes and twine.

Flower colour ranges from white through pink and red shades to orange, terracotta and yellow tones, each tiny floret with a white or golden eye. In many varieties the flower colour changes as it matures, and while sometimes this creates an attractively harmonious effect in some varieties the effect can be less appealing. Achilleas are popular with insect pollinators, are good for cutting and they can also be cut for drying.

Good impact plants

Taller achilleas are good impact plants for the back of the border, while smaller varieties are good in front of shrubs and with other perennials in mixed plantings. Deadheading significantly prolongs their flowering season into autumn, especially if the plants are not allowed to dry out.

The flat flowerheads of achilleas look well with dainty grasses, with the upright spikes of salvias and with the smoky clouds of bronze fennel foliage or the bolder foliage of heucheras.