H5 - Hardy (cold winter)

Plants hardy in cold British winters, well suited to most gardens including many inland locations where H4 plants can be less dependable.

What it means

H5 plants tolerate approximately -15 to -10 degrees C and cope with a cold winter. They suit most of the UK, particularly colder inland districts where an average H4 choice may be borderline. They are also sensible selections for exposed gardens, provided soil conditions match the plant. Even hardy plants can be damaged by winter wet, wind or sudden late frost. This rating describes plant cold tolerance, not a regional map.

Example plants

Typical H5 plants include many hardy roses, crab apples, hardy geraniums, delphiniums, lupins, hostas, hellebores and spring bulbs. A wide range of deciduous shrubs, fruit trees and established conifers also falls here. Native-style and traditional cottage-garden planting often draws heavily on H5 material, although named cultivars should always be checked because breeding can alter hardiness.

Protecting these plants

Established H5 plants usually need no frost protection. Concentrate on good planting practice: avoid waterlogging, stake tall perennials against winter wind and mulch exposed roots after planting. Protect containers, whose roots freeze more readily than border soil, by grouping pots and insulating them from cold surfaces. Newly planted trees and shrubs benefit from wind shelter and regular watering until established.

RHS hardiness ratings describe a plant's cold tolerance, not a geographic zone. Local conditions vary; the RHS or a local garden centre can advise. Page updated 18 Sep 2026.