People should install evergreen plants in window boxes and allow sections of their gardens to grow wild to help bees survive the winter, the Government has urged.

Experts are calling for a nationwide effort to protect the threatened species during the cold months, including boosting food supplies by planting winter-thriving shrubs and ivy, as well as early flowering bulbs like crocus and snowdrop.

Garden owners are also encouraged to leave suitable places for hibernation undisturbed, by letting areas of lawn grow long, in particular north-facing banks, where bees like to burrow.

Bee numbers have declined sharply in recent decades, mainly due to a 97 per cent reduction in flower-rich grasslands since the 1930s and use of agricultural pesticides.