Frost Protection

This morning we had the second noticeable frost of autumn. Everything has survived so far, but I am concerned about the impact the heavier frosts will have through winter. Last year I lost a lot of shrubs that were supposed to be frost hardy.

I think some didn’t survive because they were too immature and hadn’t become established in time. Others, like the Grevillea “Ned Kelly” are not the best kind of plant to grow in a heavy-frost prone area – but I didn’t find out about that until I lost one last year; and a second barely pulled through. That surviving plant is now looking very healthy, but it will certainly suffer again when we get those few -6 degree days that are a regular winter feature in this area.

I’ve been trying to think of a convenient way of protecting some of my frost prone plants overnight. I don’t want to use anything permanent because I still want the garden to look attractive during the day. I don’t feel like covering significant parts of it for a complete quarter of the year.

The best idea I’ve come up with so far is to drive two garden stakes into the ground beside it. I’ll put them in at an angle, leaning over the susceptible bush. Each evening I’ll tie plastic sheeting to those stakes to form a lean-to which will hopefully keep the worst of the frost off the plant. I wasn’t sure how to secure the plastic at the bottom to make sure it wasn’t blown around too much in the wind; then yesterday I heard a helpful tip on the Alternative Kitchen Garden podcast that may be adaptable to suit the situation. It was a suggestion for reusing empty drink bottles.
I will try tying 2 litre plastic milk bottles filled with water to the bottom of the sheet, which will hopefully give it enough weight to hold it securely.

All of the sheeting and the bottles can be removed in the morning and therefore return the garden to normal during the day. The stakes themselves shouldn’t be too intrusive and can be left in position over winter.