Gardening Zones Explained
If I’m being totally honest, when I first started to stock up my garden beds, borders and containers I adopted a very technical strategy with regards to the plants I selected – which ones look pretty! But as our gardening bravery gradually grows, we expand our knowledge and begin to consider soil type, position, habit etc and one question we regularly get asked is “What Gardening Zone am I in?”
It is definitely a good idea to be mindful of what plants would be suitable for the area in which you live and if a specific plant will be able to cope with the weather conditions. A quick google search on plant websites can help to give us an idea but it can be a little mind boggling as many will refer to USDA zones with the UK using RHS zones H6 to H1a. It may seem like a strange time to ask this question but don’t be fooled, late autumn and winter will soon be here and to make sure your plants are suitable it’s a good idea to check.
Gardening Zones are defined by the RHS as the following.
RHS Rating |
Temperature |
Hardiness |
USDA Zone |
H6 |
-4°F to 5°F -20°C to -15°C |
Hardy Very Cold Winter |
6,7 |
H5 |
5°F to 14°F -15°C to -10°C |
Hardy Cold Winter |
7,8 |
H4 |
14°F to 23°F -10°C to -5°C |
Hardy Average Winter |
8,9 |
H3 |
23°F to 24°F -5°C to 1°C |
Half-Hardy |
9 |
H2 |
34°F to 41°F 1°C to 5°C |
Tender Cool |
10 |
H1c |
41°F to 50°F 5°C to 10°C |
Warm Temperature |
11 |
H1b |
50°F to 59°F 10°C to 15 °C |
Subtropical |
12 |
H1a |
15°C |
Tropical |
13 |
When considering your zone, consider the prevailing weather conditions in your local area and soil types can also make a plant more or less hardy. Free drained soil and a sheltered position can also help plants survive outdoors even when the plant is not classified as hardy.
We had lengthy discussions about this subject when we launched our lovely new website last year as we wanted to make it a little less daunting and as user friendly as possible. At Plants2Gardens we interpret hardiness zones into an easier method. On our website we specify if a plant is Fully Hardy and this means it will survive anywhere and has been tested by Ken, Louise and James in their own gardens. If we state Tender below a certain temperature this is what we think the plant prefers to be at rather than a definite minus number. We also think its handy to include what type of soil drainage a plant prefers and often this is backed up in the description too.
We have tried hard to include as much useful information as possible on our website but you all know where I am if you have any questions and you are of course more than welcome to drop me an email.
I hope you all didn’t zone-out reading this!
Take care,
Lins.