• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Salvia nemorosa 'Amethyst'

Perennial salvias come in a vast variety of styles, but the short and prolific summer flowering types, such as 'Amethyst', are easy and invaluable. The stems branch well from the base and the long spikes of flowers open from June, keep coming till October and retain their purple colouring even after the individual florets have dropped. Prolific in any sunny place with well-drained fertile soil. 60cm (2ft)

Phlox paniculata 'Windsor'

More than 60 years old and still growing strong, its colour - vivid carmine with a darker eye – and its reliability still ensure it holds its own with the many that have been introduced since. Shorter than many and may not need support. Happy in any fertile soil and best in a little shade, though happy in full sun if the soil never dries out completely. 60cm (2ft)

Papaver orientale 'Karine'

Oriental poppies come in both brash, vivid colours and delicate pastel shades and the soft pink of 'Karine', enlivened by a rather variable reddish basal zone, is a lovely May/June partner for tall bearded irises. Best with discreet support to prevent rain knocking them over, the foliage turns ragged after flowering but Cosmos planted nearby will expand to hide it. Happy in sun and most good soils. 60-70cm (24-28in)

Leucanthemum x superbum 'Aglaia'

Shasta daisies were once little more than monster versions of the roadside ox-eye daisies but 'Aglaia' is typical of a more intriguing style. Its impressively frilly flowers have each slender petal prettily dissected at the tip; they open from June to September on relatively neat and bushy plants. Happy in full sun and any reasonable soil, usually needs discreet support. 50cm (20in)

Kniphofia 'Bees' Sunset'

Impressive vertical spikes of golden orange flowers from May to July, become brighter and then yellow as they age, and are held on harmoniously coppery green stems. The flower heads look a little disorganised but are bright and prolific. Happiest in deep, rich soil in full sun and with good winter drainage. Named for Bees Nursery, who financed the plant hunting trips of George Forrest and Frank Kingdon-Ward. 75-120cm (30-48in)

Iris 'Titan's Glory'

No perennial or mixed border is complete without tall bearded iris and 'Titan's Glory' features unusually large violet flowers with ruffled edges, plus the sparkle of a bright blue beard. The fragrant flowers have real presence, are at their best in June and enjoy full sun and any well-drained fertile soil. Every three years, divide and replant after flowering. 95cm (38in)

Geranium 'Orion'

An outstanding perennial, and a big step forward from the older rather similar 'Brookside', its spreading habit ensures that it makes good ground cover and the sharply dissected leaves set off large, bowl-shaped, lavender blue flowers with overlapping petals, purple veins and a white centre. Flowering from June to August, and happy in sun and any reasonable soil that does not dry out. 60-80cm (24-36in)

Dianthus ‘Cranmere Pool’

New garden pinks, with their fragrant flowers set off by slender grey foliage, are introduced every year but the 40-year-old 'Cranmere Pool' is still well worth growing. The large double flowers are white with the faintest blush and contrast with the deep blood-red zone at the heart. Flowering all summer, the flowers are scented though not strongly. 30cm (12in)

Delphinium 'Fenella'

A classic blue delphinium, the spikes are packed with vibrant gentian blue flowers, each with a dark eye. The florets are small compared with some similar varieties, but 'Fenella' has the advantage of being a robust and resilient garden plant and makes a vivid impact at the back of the border. Best in sun, in fertile soil that is not too wet; staking is essential. 1.5-1.8m (5-6ft)

Anemone x hybrida ‘Honorine Jobert’

Pure white flowers, with broad overlapping petals around a ring of golden anthers and a green eye, open on branched airy stems from August to October above bold dark leaves each with three leaflets. Happy in sun or a little shade, and best staked discretely – just in case – but can be over vigorous. Introduced as long ago as 1858, and sometimes sold simply as 'Alba'. 50-120cm (20-48in)

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