Frost pocket

A frost pocket, also known as a frost hollow, is an area of land which has a higher risk of frost and which has a longer season of frost (ie frosts start earlier in the winter and finish later in the spring). The minimum temperatures can be significantly lower in a frost pocket.

Frost pockets are often found in dips and valleys where cold air remains for longer than in surrounding areas, particularly where hedging or other shelter prevents the cold air escaping. A pool of morning mist congregating at ground level, when other areas have cleared, is a good indicator of a frost pocket. If you identify a frost pocket in your garden, making gaps in any surrounding shelter can lessen the effect.

Avoid planting early spring flowering plants in frost pockets, particularly fruit trees, as the flowers may not survive. Frost pockets should also be avoided for plants which are frost hardy, even if they survive elsewhere in your garden.