Characteristics foliage deciduous habit bushy hardinesshardiness ratingsall ratings refer to the uk growing conditions unless otherwise stated. Minimum temperature ranges (in degrees c) are shown in bracketsh1a - under glass all year (15c) h1b - can be grown outside in the summer (10 - 15) h1c - can be grown outside in the summer (5 - 10) h2 - tolerant of low temperatures, but not surviving being frozen (1 to 5) h3 - hardy in coastal and relatively mild parts of the uk (-5 to 1) h4 - hardy through most of the uk (-10 to -5) h5 - hardy in most places throughout the uk even in severe winters (-15 to -10) h6 - hardy in all of uk and northern europe (-20 to -15) h7 - hardy in the severest european continental climates ( h7 colour sunlight full sun aspect south-facing or west-facing exposure sheltered or exposed soil loam moisturemoist but well-drained soilloam phalkaline, neutral, acid size ultimate height 0. 5-1 metres ultimate spread 0. 5 metres how to grow cultivation best grown in full sun and moist but well-drained soil that is not wet in winter. Plants can be short lived in heavy soils propagation propagate by seed or division in spring suggested planting locations and garden types flower borders and beds coastal cottage & informal garden city & courtyard gardens how to care pruning cut back after flowering to encourage fresh foliage and a longer flowering season pests generally trouble free but young growth may be damaged by slugs and snails diseases generally trouble free but may be affected by rust diseases did you find the information you were looking for?rhs members can get exclusive individual advice from the rhs gardening advice team. Join the rhs nowget involvedthe royal horticultural society is the uks leading gardening charity. We aim to enrich everyones life through plants, and make the uk a greener and more beautiful place.).