We have found 34 plants that meet your criteria.

Price Pruned
Yarrow ‘Achillea millefolium Lilac Beauty’ An unusual lilac, yarrow NOW £5.49 Buy
Hyssop ‘Agastache Black Adder’ Distinctive violet, bottlebrush flowers £5.99 Buy
Allium Purple Sensation ‘Allium hollandicum Purple Sensation’ Rich, deep purple globes £3.50 Buy
Price Pruned
Allium ‘Allium cristophii’ Huge globes of star-like, lilac flowers NOW £5.99 Buy
Allium cristophii ‘Allium cristophii’ Huge globes of star-like, lilac flowers £5.00 Buy
Allium Globemaster ‘Allium Globemaster’ Enormous, deep violet globes £5.00 Buy
Allium ‘Allium hollandicum Purple Sensation’ Rich, deep purple globes £5.99 Buy
Allium Schubertii ‘Allium schubertii’ The flowers look like giant fireworks £7.50 Buy
Round-headed Leek ‘Allium Sphaerocephalon’ Small, wine-coloured flowers on tall stems £4.00 Buy
Butterfly Collection ‘Butterfly Collection’ Summer-flowering wildflowers £2.99 Buy
Cornfield Collection ‘Cornfield Seed Collection’ A collection of native wildflowers £2.99 Buy
Price Pruned
Lavender ‘Lavandula angustifolia Melissa Lilac’ Large, lilac flowers in summer NOW £4.99 Buy
Price Pruned
Lavender ‘Lavandula angustifolia Munstead’ A compact variety with blue-purple flowers NOW £4.99 Buy
Price Pruned
Bergamot ‘Monarda Ou Charm’ Pretty, pink flowers and purple bracts NOW £5.49 Buy
Catmint ‘Nepeta x faassenii Kit Cat’ A dwarf variety with purple flowers £5.99 Buy
Salvia ‘Salvia nemorosa Amethyst’ Lilac-purple spires of flowers £5.99 Buy
Chives ‘Allium schoenoprasum’ Edible leaves and purple, button flowers £3.99 Buy
Angelica ‘Angelica gigas’ Tall, dramatic burgundy flowers £6.99 Buy
Balkan Cranesbill ‘Geranium macrorrhizum Bevan's Variety’ Magenta flowers. Perfect for suppressing weeds £5.99 Buy
Price Pruned
iceberg ‘Lavandula angustifolia Hidcote’ A compact lavender, with intense, violet flowers NOW £4.99 Buy