Gardening Which? has trialled hundreds of perennials to find the most impressive and reliable for anyone wanting to create a dazzling summer border.
Perennials are the mainstay of summer borders, providing colour and interest all season, but there’s a bewildering variety available. This month’s Gardening Which? reveals the pick of the bunch from our trials.
For early summer, our experts found that oriental poppies and astrantias are good choices.
Daisies for high summer
Papaver orientale ‘Curlilocks’ gives a stunning, if short-lived, show, while for high summer, daisies such as the yellow blooms of the Helenium ‘Butterpat’ are perfect.
For late-summer flowering, nepeta is hard to beat. The pretty, upright N.racemosa bloomed for almost six months in the Gardening Which? trial, and though some campanulas can disappoint, the pale pink C. lactiflora ‘Loddon Anna’ gave up to 12 weeks of continual colour.
To add interest to borders, gardeners can experiment with different-shaped perennials such as spire-like verbascums and delphiniums.
The best performing tall delphinium was the deep lilac double-flowered ‘Mighty Atom’. But to create an impact, nothing beats the bold, hot colours and spiky evergreen foliage of Kniphofia, or ‘red hot pokers’, says Gardening Which?.
Editor Julia Boulton said: ‘Herbaceous perennials are wonderful for creating interesting borders and a colourful garden right through the summer until the end of autumn. Choose from our recommended varieties to create the ultimate herbaceous border.’