Dahlia 'Tartarus' (P)

• The RHS Award of Garden Merit (AGM) helps gardeners choose the best plants for their garden.
• 
  RHS Plants for Pollinators plants

  This plant will provide nectar and pollen for bees and the many other types of pollinating insects.

  It is included in an evolving list of plants carefully researched and chosen by RHS experts. Divided into 3 groups these lists, linked below, are maintained by a team of RHS staff and are reviewed annually.

  • Garden Plants
  • Wildflowers
  • Plants of the World

Cultivation

Plant tubers 10-15cm deep in fertile, humus-rich, well-drained soil, in full sun; cut back to near ground level in mid-autumn, then in mild areas and on well-drained soils leave the tubers in the ground and protect with a deep organic mulch, while in colder areas or on heavy soils lift and store the tubers and replant in late spring after all danger of frost has passed; for more advice, see dahlia cultivation

Propagation

Propagate by basal softwood cuttings taken in spring from shoots from stored tubers, or divide the tubers, ensuring that each division has a viable bud

Suggested planting locations and garden types

• City and courtyard gardens
• Cottage and informal garden
• Patio and container plants
• Wildlife gardens
• Cut flowers
• Flower borders and beds

Pruning

Deadhead to prolong flowering

Pests

May be susceptible to aphids, capsid bug, earwigs, caterpillars, slugs, glasshouse red spider mite, and onion thrips

Diseases

May be affected by powdery mildews, dahlia mosaic virus, cucumber mosaic virus, tomato spotted wilt virus, storage rots, leafy gall, crown gall, dahlia smut, grey moulds, fungal leaf spot, phytophthora, sclerotinia, verticillium wilts, and virus diseases