Winter Frost and Plants
Good landscape design is always a considered response to the requirements of a design brief, the physical environment and the contextual setting in which a development is taking place. When designing in Canterbury there are some specific factors that need to be allowed for to create landscapes that are great spaces for people to be in and that are visually cohesive, distinctive and successful.
A factor that can’t be ignored in Canterbury is to design with regular hard winter frosts in mind. This will primarily have a distinct impact on garden design. Plant selections in Canterbury require specimen that have a good degree of ‘hardiness’, which describes a plants ability to survive frosts.
This means for example we generally can’t plant the frost tender sub-tropical that do so well in Auckland’s climate, or even some of the frost tender natives people love, like Nikau Palms and Pohutakawas.
However, the frequency of frosts and a cooler winter, coupled with a warm summer will also mean that Canterbury gets true seasons and our flowering plants and trees will tend to put on better seasonal displays than our ‘sister’ northern cities.
If you live in Sumner, or on one of the hill suburbs, chances are your property is above the ‘frost line’ and you can get away with a wider plant selection where frost tender succulents for example will perform well that just won’t survive on the flat. In these scenarios a good degree of local knowledge and an ability to read existing vegetation patterns is essential for successful garden design that works with an existing niche microclimate.
Pockets of frost shelter can be established over time on most properties by plantings and built structure which create their own microclimate and protection. A shrub or tree canopy can provide shelter for frost tender seedlings and young plants to establish.
The leave overhang on a house can provide some frost shelter which citrus for example will typically require. Another unexpected frost free place around most homes is beside the external heat pump condenser unit. The air flow of the operating unit in winter creates an airflow that can stops a frost settling allowing for some interesting plant choices.