Our dahlia plants collection at Boma spans every flower form — from compact ball dahlias and neat pompon types ideal for cut flowers to the spectacular large flowers of dinner-plate decoratives such as 'Café au Lait' and 'Babylon Red'. Cactus dahlias with their spiky, twisted petals add drama to borders and cutting gardens, while single and open-centred dahlia plants are outstanding for pollinators. We stock dahlia tubers through spring for planting from scratch, alongside potted dahlias from late spring for those wanting instant summer colour. All dahlia varieties are available at Boma in Kentish Town throughout the season.

Plant dahlia tubers after the last frost, typically from late April in London, in a sheltered spot in full sun with well-draining soil enriched with well-rotted manure at planting time. Set tubers 10–15cm deep with the eye facing upward. Dahlias benefit from regular watering and balanced fertiliser once established, switching to a high-potash feed when flower buds appear to encourage spectacular blooms. Deadhead consistently to redirect energy into new blooms and prevent fungal diseases in congested foliage. Pinch out growing tips at 40cm to encourage bushy, multi-stemmed plants with more stems for cutting. In dry periods, water deeply at the base rather than overhead.

After the first frosts blacken dahlia foliage, carefully dig dahlia tubers and allow to dry before placing in winter storage — a frost-free place such as a cool, dry garage or shed is ideal through winter. In London's relatively mild conditions, well-mulched dahlias can survive winter in the ground, but lifting remains safer practice in colder or exposed gardens. Dahlias are tender perennials: treat as annuals or invest in careful lifting and storage for the best plants season after season. As cut flowers, dahlias last up to a week in a vase, making them among the most rewarding flowering plants for home cutting gardens.