A tall, perfectly proportioned perennial that towers above you, casting silhouettes against the sky. Hummocks of celery-like leaves throw out chunky stems with whorls of delicate, pale green flowers forming neatly arranged plates. This makes an architectural feature that lasts well into winter, with the bleached skeletons standing proud of surrounding vegetation. It self-sows freely and, planted in numbers, creates an other-worldly scene of a Dr Zeuss story.
Height and spread: 3m x 1m.
Soil and situation: Well-drained soil in full sun
Buy from Great Dixter nursery
01797 253107
greatdixter.co.uk Photograph: Fergus Garrett
Who would have thought that a diascia would feature in a list of first-class plants, but this one is full of surprises. It produces an abundance of small, deep salmon pink flowers from June to early October, carried on tall, slender stems. Its meandering habit means it mixes well with other border companions. Plants root readily from stem cuttings taken in summer.
Height and spread: 1m x 0.5m.
Soil and situation: Well-drained soil in sun or partial shade.
Buy from Proper Plants
01208 872291
properplants.com. Photograph: Alamy
This is the most distinguished opium poppy. Its stiff stems carry several deep plum-purple flowers with tissue-paper petals, bursting from tightly-packed buds unfurling like a freshly emerged butterfly stretching its wings. Graceful seed pods follow. 'Lauren's Grape' will self-sow, albeit not as prolifically as other strains of P. somniferum, so I'd recommend surface sowing seed into pots in early spring, pricking out into trays, then planting into beds when large enough to handle.
Height and spread: 1m x 0.5m.
Soil and situation: Fertile, well-drained soil in full sun.
Buy from Seeds By Size
01442 251458
seeds-by-size.co.uk Photograph: Fergus Garrett
This herbaceous spurge is superior to all others. The lime-green flowers sit like plates on top of tall stems. The contrast between the foliage and the flowers is dramatic, with the effect continuing from June into September. Plants self-sow and come surprisingly true from seed.
Height and spread: 1.5m x 1m.
Soil and situation: Well-drained soil in full sun.
Buy from Great Dixter nursery
01797 253107
greatdixter.co.uk. Photograph: Martin Hughes-Jones/Garden World Images
The Japanese climbing fern has made a nuisance of itself as a roadside weed in the southern US. This is where I first fell in love with it and now have plants growing in pots in a hot greenhouse at Great Dixter. Tender and surprisingly rare in cultivation, it has jade green fronds and twining tendrils. Supported on pea sticks, it makes a tantalising pot plant for a shady corner.
Height and spread: 3m x 0.5m.
Soil and situation: Well-drained soil in partial shade.
Buy from World Of Ferns
01248 600385
world-of-ferns.co.uk Photograph: John Glover/Alamy
This fleabane is a prolific performer, producing masses of white daisies with yellow centres from June to November. Used en masse, the effect is as dramatic as a drift of snow. Run through other border plants , the result is as light and airy as a dusting of white. Unreliable as a perennial, it's best to grow from seed in autumn or, better still, allow self-sown seedlings to do the work for you. It looks smart partnered with Salvia guaranitica 'Blue Enigma' and dusky-red Helenium 'Moerheim Beauty'.
Height and spread: 1m x 0.5m.
Soil and situation: Full sun in any fertile soil.
Buy from Great Dixter nursery
01797 253107
greatdixter.co.uk. Photograph: Gap Photos
This stands head and shoulders above the other bergenias currently on trial at Wisley. In winter, its glossy leaves are washed in burgundy, slate grey and green with light liver under-sides . The leaves turn green during summer but retain much character with a highly glossed appearance. Strong pink flowers on reddish stems appear from April to May.
Height and spread: 0.3m x 0.5m.
Soil and situation: Any soil in sun or shade.
Buy from Binny Plants
01506 858931
binnyplants.co.uk. Photograph: Fergus Garrett
This tender sage from Brazil has imperial qualities. Large, roughly textured leaves are held at intervals on upright stems. Small reddish hairs cover the plant, giving it a haze of cinnamon, and velvety, rich burnt-red flowers erupt from the tips of the branches. It makes a fiery display and flowers all summer long.
Height and shade: 2m x 1m.
Soil and situation: Well-drained soil in full sun.
Buy from Ashwood Nurseries
01384 401996
ashwood-nurseries.co.uk Photograph: Fergus Garrett
The Chinese walnut is a stylish architectural plant that needs strong partners, such as tree ferns and bamboos, to set it off. When cut back to a multi-stemmed shrub, it is transformed into a prehistoric-looking beast with outward reaching arms, each carrying sweeps of dark green leaves with hairy undersides. In winter, fat buds protrude from chunky stems.
Height and spread: 8-10m x 5-6m (can be controlled by regular pruning).
Soil and situation: Sun or part shade in most fertile soils.
Buy from Crug Farm Plants
01248 670232
crug-farm.co.uk Photograph: Fergus Garrett
A show-stopper: 8cm-wide, multi-petalled flowers with yellow anthers set against rich green foliage. The buds are almost reptilian in appearance and are produced all summer long. Seed mustn't be sown too early – May under glass is soon enough for planting out in June.
Height and spread: 1m x 0.5m.
Soil and situation: Fertile, well-drained soil in full sun.
Buy from Seeds By Size
01442 251458
seeds-by-size.co.uk. Photograph: Carol Casselden/Great Dixter House
