We have found 136 plants that meet your criteria.

Price Pruned
Yarrow ‘Achillea millefolium Lilac Beauty’ An unusual lilac, yarrow NOW £5.45 Buy
Monkshood ‘Aconitum Sparks Variety’ Deep violet hooded flowers on tall stems £6.95 coming soon
Hyssop ‘Agastache Black Adder’ Distinctive violet, bottlebrush flowers £5.45 Buy
Hollyhock (Althea) ‘Alcea rosea Nigra’ Deep burgundy flowers £5.45 coming soon
Price Pruned
Allium ‘Allium cristophii’ Huge globes of star-like, lilac flowers NOW £5.95 coming soon
Price Pruned
Allium ‘Allium Globemaster’ Enormous, deep violet globes NOW £5.95 coming soon
Allium ‘Allium hollandicum Purple Sensation’ Rich, deep purple globes £5.95 coming soon
Chives ‘Allium schoenoprasum’ Edible leaves and purple, button flowers £3.99 coming soon
Price Pruned
Allium Schubertii ‘Allium Schubertii’ Giant pink starbursts NOW £4.95 coming soon
Price Pruned
Round-headed Leek ‘Allium sphaerocephalon’ Small, wine-coloured flowers on tall stems NOW £5.45 coming soon
Angelica ‘Angelica gigas’ Tall, dramatic burgundy flowers £6.95 Buy
Price Pruned
Columbine ‘Aquilegia McKana Hybrids’ Bonnet-like flowers in a range of colours NOW £4.95 Buy
Price Pruned
Granny's Bonnet ‘Aquilegia vulgaris var. stellata Black Barlow’ Striking dark purple, double flowers NOW £4.95 Buy
Price Pruned
Granny's Bonnet ‘Aquilegia vulgaris William Guinness’ Unusual purple-black flowers NOW £4.95 coming soon
Cobra Lily ‘Arisaema speciosum’ A wonderfully exotic looking plant £6.95 Buy
Wild Ginger ‘Asarum europaeum’ Lustrous foliage for a shady corner £5.95 Buy
New England Aster ‘Aster novae-angliae Violetta’ Beautiful deep purple flowers £5.95 Buy
Michaelmas Daisy ‘Aster novi-belgii Purple Dome’ Masses of violet-purple flowers in late summer £5.95 Buy
Michaelmas Daisy ‘Aster pyrenaeus Lutetia’ One of the most reliable asters £5.45 Buy
Michaelmas Daisy ‘Aster sedifolius nanus’ A small plant that has big impact £5.95 Buy