Persicaria bistorta ‘Superba’
Long stems hold fluffy towers of soft-pink flowers, which form pom-pom-like flowerheads from summer to early autumn. It’s a showstopper of a plant with impressive, green, heart-shaped foliage. H: 90cm, S: 90cm; £15 for 9cm pot. hayloft.co.uk
Acanthus mollis ‘Rue Ledan’
This unusual cultivar of acanthus has an architectural elegance with spires of hooded white floating flowers on silvery-green stems. It will illuminate shady areas in the border and is deer and rabbit resistant. H: 1.2m; £16.93 for 3 x 9cm pots. sarahraven.com
Hollyhock ‘Nigra’
A unique variety of hollyhock, this plant produces striking, chocolatey blooms with lemon centres, tinged with red. Planted in full sun, they will reward you with flowers until September. H: 2m, S: 75cm; £2.99 for 9cm pot. blackdognursery.co.uk
Delphinium ‘Dusky Maidens’
The impressive…