An easy way to protect plants from frost heave is by applying a thick layer of mulch to the soil. This acts as a protective barrier between the soil and cold air, insulating roots and protecting plants from temperature fluctuations.
Biodegradable mulches include bark chippings, straw and compost.
These will not only protect plants from frost but also improve the soil as they break down. Alternatively non-bio-degradable mulches, like slate chips, pebbles and decorative aggregates, offer a smart-looking layer of frost protection.