Hardiness Guide

This serves as general guide by Urban Jungle. For more specific advice based upon the exact care required, please consult a member of the Urban Jungle team.

Important points to consider:-

  • One night at -15C can be less damaging to plants than 7 consecutive nights at -7C.
  • Good soil drainage plays an important part in a plant’s ability to withstand winter outdoors.
  • Some plants are very frost tolerant but will not withstand a cold/wet combination. Sharp drainage and a cloche may be required for them to survive sub zero temperatures..
  • Young plants are more vulnerable to frost than mature specimens.
  • There are different micro-climates within the same garden. Plants close to the house, especially if south or west facing can withstand colder  nights than those planted in exposed parts of the same garden.

You may find further information within each product’s label or web page, or from the available list of plants within our FAQs.

Code

Temp

Category

Description
1 15C+ Indoor Grow as a houseplant or under heated glass.
2 10 to 15C+ Indoor / Outdoor Grow indoors, or outdoors in summer in a sheltered spot.
3 5 to 10C Tender Grow outdoors in summer, and in a heated glasshouse in winter.
4 1 to 5C Tender Grow outdoors or under glass without risk of frost.
5 -5 to 1C Half-Hardy Hardy in coastal/mild/sheltered areas. Will not tolerate hard/sudden frost. May require winter protection in situ. such as fleece or straw mulch.
6 -10 to -5C Hardy May suffer at altitude, central/northerly locations, harsh winters, cold gardens and when grown in pots.
7 -15 to -10C+ Hardy Will survive most severe winters but may be at risk in central/northerly locations and in pots. Top growth may be destroyed but will usually re-grow.
8 -20 to -15C Hardy Will survive severe winter, but may need protection when grown in pots.
9 -20C & Colder Very Hardy Hardy in the severest European climates.