September

Mammoth Sweet Peas belongs to a type of sweet pea called an 'Early Multiflora Gigantea'. Marked by the longest stems, and large fragrant blooms, they are very popular with commercial cut flower growers. 'Mammoth Crimson' produce large crimson-red flowers that are borne on beautifully long stems.

The Kniphofia hybrids have extended both the flower colour and height range. The usual fiery reds and oranges work particularly well in a planting scheme based on 'hot' colours - use them to light up sultry August borders. The cooler yellow, cream, ivory and sometimes green flowers is more restful.

Knautia arvensis is an attractive native perennial herb of well drained grassland. It can be found throughout Europe in meadows, rough pasture, hedgerows and verges. Though it is by nature a perennial, it will flower and produce seed the first year if grown as an annual, either autumn or spring sown.

'Kermesina' is an attractive and popular cultivar of Iris versicolor. Flowering from May through to July with claret-purple flowers with ruffled petals and bold purple veining. It may be grown in shallow standing water or moist shoreline soils and suitable to be grown in constantly moist humusy soils of a border.

Iris versicolor is one of the few species in garden cultivation. Although happiest at the waterside the plants will also perform well under average to moist border conditions. Flowering from May through to July, each stalk produces up to five violet-blue flowers with ruffled petals and bold purple veining.

Yellow Flag Iris is a common and widespread native plant in Britain. This good-looking plant is a wetland plant that is especially showy in bloom and has been transplanted into well-watered gardens all over the world.

Iris bulleyana is a classic species Iris from western China. It belongs to a small group of oriental species which are entirely hardy and are of great value to the gardener. The plants are successful in any moist garden soil. Flowering from June to July, the blooms with mid purple flowers and dark purple veins.

A deep blue carpet of bluebells is an unforgettable sight to anyone visiting many of our native woodlands. The spring spectacle of seeing a wood not only greening, but also 'blueing' is one of the joys of the year. When bluebells are in flower, spring has truly arrived.

Hosta are grown predominantly for their outstanding foliage, from leaves as small as a teaspoon up to those larger than a dinner plate, colours range from deep blues to silvers, darkest shiny greens to bright yellows, from a single solid hue to the myriad of variegations the choice is almost overwhelming.

Herniaria glabra is a relatively unknown perennial that deserves to be used more often in our gardens. The nursery industry calls it ‘Green Carpet’ and well they should. This lovely bright green creeper spreads effortlessly in all directions. An excellent choice for between flagstones or as a lawn substitute.

Based on hybrids bred by the doyenne of the Hellebore world, Helen Ballard, these must be some of the finest and most beautiful of the race we have to offer. Large flowers are produced in a variety of colours from dark purple to white - often extravagantly mottled and marked.

Heliopsis ‘Summer Nights' is a special selection made by Dale Hendricks of North Creek Nurseries, USA. Introduced in 2004 it produces a profusion of single blooms in early to mid-summer, with rich, deep golden-yellow petals and deep mahogany centres. The foliage is red-tinted and the stems are tinted dark burgundy.

From the Tian Shan Mountains of northern China comes this tough little subshrub that is among the finest expressions of silver foliage to be found. Helichrysum thianshanicum is a superb silver leaved evergreen, subshrub that forms a tight mound of eye-catching silver foliage.

Most gardeners are familiar with the annual sunflower, however, it is the perennial varieties that coexist most happily with other garden plants. Helianthus mollis is a lovely perennial with butter-yellow flowers. It grows 120cm tall and requires little more attention than an annual cutting to the ground.

Perennial sunflowers typically don’t grow quite as tall and large as their annual friends. However Helianthus maximiliani is a wonderful exception. It grows slowly through the summer months as a group of short stems, until late summer when the stems bolt and the flowers head for the sky.

Helianthus ‘Vanilla Ice’ is one of the prettiest sunflowers varieties available. With clusters of delicate pale creamy-yellow flowers with dark chocolate centres this compact variety grows to just 120 to 150cm (4 to 5ft) tall is suitable for the border or can be left add a naturalised charm to a wildlife friendly garden.

Sunflower 'Soraya' is the first Sunflower ever to win an AAS award. It produces lovely rich tangerine-orange flowers with dark brown centres The vigorous, self-supporting plants stand 150 to 180cm (5 to 6ft) tall. Prized for cut flower arrangements, they produce 20 to 25 flowers from each plant.