As the snowflakes fall and frost sets on the foliage of trees, the scenic landscapes begin to resemble a winter wonderland. With that being said, the cold conditions do make a number of gardeners panic as their attention turns to the survival of their plants and their ability to cope with these extreme weather conditions unaided – what we call ‘hardiness’.
Hardiness relates to a plant’s ability to survive outside during winter, and as temperatures drop around the country, what better time to discuss the topic. Initially, when choosing a plant species, one must ask themselves “will this species endure the conditions in my area?” The main conditions to be considered are wet and cold temperatures, which the UK is of course familiar with! Certain plants will take to a variety of cold conditions as some will be able to take a light frost, whereas others can withstand freezing temperatures for a considerably long time.
The origin of a plant can impact its ability to survive in harsh conditions. Plants native to the UK have adapted to unusual environments and external factors, such as harsh climates, whilst other plants can thrive in a diverse range of locations and are able to adjust to different environments. A great number of these native plants are deciduous and have therefore adapted over thousands of years to attain features that ensure their survival. Deciduous plants shed their foliage during the winter season, whereas their alternative evergreens keep their leaves and so are exposed to the effects of freezing. Evergreens however shouldn’t be disregarded as their thick structures can, more often than not, cope with cold temperatures. Especially when planted to maximise their exposure to the sun or sheltered to protect them from winds.
The RHS have recently improved its hardiness rating scale. Based on minimum winter temperatures with each of the seven categories separated by 5°C ranging from 15°C to -20°C. The scale gives an indication as to where a plant can be positioned, determined by its rating on the scale. Unfortunately, the ratings of a plants hardiness can’t be related to various locations across the UK. This is due to the inconsistent weather that seems to change every year.
Gardeners who have stayed in one location over a number of years become familiar with their conditions and have maintained gardens that thrive throughout the year. For those who are new to a location, we advise becoming familiar with your seasonal changes by noting down signs of first and last frost, along with frost frequency, rainfall and wind direction. Or, why not get to know your local garden enthusiasts (easily spotted at your local allotment or found tending to their front gardens on a daily basis!) and ask for their findings to compare to the RHS rating descriptions.
A number of gardeners have the tendency to look past the initial stage of research and opt for their favourite species with no regard to ‘hardiness’. Before choosing a plant for your garden, ensure you gather all the information you need in regards to the species and your area specific conditions. This will stand you in good stead and allow you to watch your plant establish through the thick and thin of the unreliable UK weather.