Before the cold weather set in (over a month ago) I could see crocus buds aplenty and I fully expected to have them in flower by now. After the cold weather, which kept me penned into my village for three weeks, I am desperate for a sign of spring to lighten my load. But I am probably not half as desperate as our hibernating bees who will shortly wake up once the temperature approaches 10C (roughly 50F).

The earliest to appear is our largest – Bombus terrestris or the Buff-tailed bumblebee. The queens measure roughly an inch in length or 20-22 mm and they need nectar and pollen now. Nectar provides energy for flight and pollen provides the necessary protein to start a new brood. Bumblebees are amazing creatures. They defy the laws of aerodynamics in order to fly at all. They can also rev up the flight motors in their stomachs chemically. This allows them to fly in much lower temperatures than honey bees. There are five species of bumblebee inside the Arctic Circle – quite a thought.

Bumblebees are the gardener’s best pollinator early in the year because they are often the only bees about. But it does not end there. They are the only bees that can buzz pollinate by shaking the pollen off the anthers as they vibrate inside the flower. This is unique to them and the solanum family (which includes tomatoes and aubergines) can only be pollinated in this way.

Early flowers are the most vital for them and the crocus, which seems to have its own built-in light meter, is perfect. It will open on bright days even in cool weather. The goblet-shaped flowers keep the air inside warm and still and warmer air encourages better nectar flow. This is why fruit crops always do best in warmer positions in the garden.

The earlier-flowering crocus tends to have smaller flowers. Crocus chrysanthus is a yellow species and named forms were selected from the start of the 20th century onwards. One was named ‘E.A. Bowles’ in the 1920s and it has yellow margins streaked in bronze and purple. ‘Jeannine’ is one of the prettiest, although sometimes hard to find. There are also silver-blue varieties and the best is ‘Blue Pearl’. These smaller ‘chrysanthus’ types are best grown in the ground rather than in grass. But the small corms are adored by mice.

The best to grow in grass are forms bred from the Alpine crocus (C. vernus). These flower roughly four weeks later (often in March) and they are more robust and larger flowered. These also persist and spread into large clumps and, hidden in grass, they are less susceptible to squirrels and mice. ‘Vanguard’ is a lovely silver lilac-grey and it flowers two weeks earlier than most – hence the name. It’s now available too – at long last. Watch for crinkly leaves, a mark of a virus, and ditch any crocus that show signs.