Traffic Light System

Pointing You In The Right Direction

TRAFFIC LIGHT HARDINESS RATING

We use three different coloured labels to give you an instant indication of a plant’s frost hardiness. These are outlined below, but please note that they are a rough guide only. We are always on hand to offer advice on individual specimens.

Green Light

Hardy anywhere in Britain below approximately 1000ft (300m).

Amber Light

Hardy in the Home Counties if sensibly sited (avoiding severe frost pockets, for example). Many Amber labelled plants are grown using cuttings from well established plants that have survived many harsh winters in South East England.

Red Light

Hardy in Atlantic coastline gardens, The Channel Islands, gardens in Central London and other large cities and conservatories.

Illustration by Paul Cox

Please note this is a tentative guide and we are always on hand to give advice about plants and their frost hardiness.

N.B.
The commonly held belief that it’s better to ‘plant small’ is true of herbaceous plants, but not necessarily true of woody plants. They need some wood on them to survive severe cold, so plants of marginal hardiness in very cold areas should really be planted larger rather than smaller, if possible.