Can “all year round cauliflower plants” that have been hardened off now withstand the frost?
Yes it should, it is not actually the frost that burns/kills the plants, its the sun first thing in the morning that melts the frost very quickly and then burns the plants, if you wash the frost off with a hose pipe or watering can they will be OK. The same goes for any plant. Cover the plant rows with some fine chicken mesh, itshould be enough to keep the frost off.
