SO JACK FROST. YOU WANT TO PLAY LETS PLAY!
According to Scandinavian legend the son of the God of the Winds is the one who brings the frost with him.
In English his name eventually became known as Jack Frost
I’m not sure how much of Jack we’re going to see of in our long term future.
Climate change is thought of mostly as warming. But as I write this, it is also causing polar vortexes in the Northern Hemisphere with extreme cold as a result.
I have heard a climate scientist say that eventually (if we don’t address the issue properly) heat will ‘win out’ over cold.
Chances are, though, Jack’s still going to visit us for a while yet.
There are strategies we can ensure are in place when Jack comes to call that will help our plants resist the impacts of frost.
And this is particularly important with succulents and cacti as frost is most often (but not always) something they are not adapted to handling in their endemic (natural) habitats.
So here’s a few tips to combat Jack:
If you live in a location where Jack visits (and I’m not referring to the alcohol form of Jack!) then choosing a plant suitable for your climate is perhaps the most important consideration.
Cold air tends to run down slopes and pool in low lying areas. Consider local topography of not just your own but neighbouring properties when choosing a planting location for your succulents and cacti. Nb. hedging can provide a barrier to the movement of cold air so you could use it, for instance, to keep cold air higher in the landscape.
If your cacti or succulent is winter dormant, it is an advantage if you can (especially if your plant is potted and moveable) keep the soil drier in winter as less water will be stored in the leaves to freeze during the cold.
Healthy plants have thicker cell walls which helps protect against frost. Liquid seaweed extracts such as Seasol will help with this. And there are other products such as rock minerals and rock mineral/beneficial microbe blends that also improve plant health and vigor.
- Conversely, excessive use of fertiliser nitrogen (N) elongates plant cell walls leaving the plant more susceptible to both cold and disease.
Soil type can have an impact on frost intensity. This is to do with the clear nights that typically precede a frost event and the release of heat retained during the day into the air by way of thermal radiation. The way this works means that, all other factors being equal, sandier soils tend toward more frosts than heavier clay soils. This can have implications for your succulent garden given the soil will be sandier.
The ‘heat island’ effect from urban development keeps the air at a higher temperature than a rural environment, which works to the city dwellers advantage.
On the same basis, micro-climates such as found below house eaves and where heat radiates from house walls can provide a frost ‘resistant’ location for planting.
Consider using frost cloth, which is designed to form a barrier between the frost and plant and trap warm air under the cloth. It has been suggested that frost cloth works well down to -6C. Anything below -3C is considered a severe frost here in Australia.