Thanks Mary.
Mahonia and snowdrops are great for bees in the spring – a nice bit of fresh pollen but no stores, if there is nectar it’s only very little and so few bees in the spring…
Crocuses certainly seem to open more in the sunshine and bees are easily chilled in the spring so sunshine is important.
Sycamore and dandelion would be the first flowers you could expect the bees to bring in surplus from and then only if the colonies are good and strong. Rape too is great for both pollen and nectar. Horse chestnut too – look out for dark red pollen.