The ‘Whomping willow’ and golden pollen

Perhaps the most famous willow in literature is the one which appears in JKR Rowling’s Harry Potter stories. However, the ‘Whomping Willow’ isn’t the only magical willow, away from the pages of novels the real-life goat willow could be described as pretty impressive too, especially when it comes to pollinators.

Male catkins covered in pollen rich anthers

There are few sights in nature as captivating as the golden male catkins of the goat willow. And the early flowering catkins are more than simply attractive to look at; they are a huge bonus for bees in very early spring when sources of pollen and nectar are scarce. The golden colour of the male catkins is down to pure pollen. Before the gold colour appears the catkins will look grey or even slightly pinky-orange.  The catkins have lots of individual flowers, each one with a tiny blackish leaf-like scale.  These minute catkin scales develop lots of grey hairs at their tips making the whole catkin appear furry, protection from the biting cold wind.  If you want to see early pollinators then park yourself near a flowering willow, for hungry pollinators rarely resist them. 

Willows are interesting trees. The goat willow (also known along with other willows as pussy willow) is large for a Scottish willow.  It is said in some quarters that there are 400 or so species of willow, and they come in all shapes and sizes such is the ability of the willow to generate cross breeds. In Scotland alone a list of trees and shrubs native to these shores would include grey willow, dark-leaved willow, tea-leaved willow, and bay willow. Scotland’s smallest tree is the dwarf willow, about 5cm or less in height and found hugging the ground on some of our most exposed mountains.

Around the Ben Lawers area, local bee expert Anthony McCluskey (who many of you will know in his Butterfly Conservation role) studied a restored woodland area, with plenty of willow, to see what insects were foraging on the catkins. He found several mining bees including the stunning Clarke’s mining bee and his Glen Lyon records broke new ground for the species. 

Just as species range can change so the uses we make of natural resources alters too. Times change and the wood of the willow isn’t particularly valued these days, but in earlier times it was used to make a diverse range of goods including handles for hatchets, baskets, peat and lobster creels, and the humble clothes peg. For many willow is synonymous with cricket bats. Indeed the phrase ‘leather on willow’ came to encapsulate the height of English summer, with the sound of a cricket ball being whacked with a willow bat ringing out on village greens up and down the nation. 

Tree bumblebee feeding on catkins

There was also a time when the willow had greater aesthetic appeal. Many Scottish families will recall a time when their family used to cut pussy willows to put in a vase of water with daffodils.  The name too conjures up the famous Wind in the Willows, beloved of children and adults now for several generations.

Salix caprea, to give the goat willow its ‘Sunday’ name, with careful coppicing can remain a ‘shrub’. But turn your back for any length of time and you may indeed have a ‘Whomping willow’ on your hands. With many stems this is a plant that can gallop to heights of around 15 metres if left unchecked.

The catkins are fascinating because a willow can produced either all male or all female catkins, but never both together on the same tree. We now know that willows are dioecious, that is the plants are either male or female, and we appreciate too that they are pollinated by the wind. Indeed despite considerable interest in the gathering hordes of pollinators in spring the key pollination time for the goat willow is actually late winter or perhaps very early spring, and usually in advance of the distinctive oval leaves showing on the tree. 

There is yet more to the willow (which can live for up to 300 years) than feeding early emerging pollinators.

The glossy green leaves act as a source of food for the larvae of several species of butterfly and moth, including in the south of England the impressive Purple Emperor. Closer to home it is worth looking out for the sallow kitten or puss moth. These are both extremely furry moths, with impressive caterpillars. The former is interesting because it is one of the species that has two generations a year in the south of its range, and only one in the north, including northern Scotland. They both feed on poplars as well as willows – the two genera are closely related and quite a number of species use both. Our native poplar, aspen, flowers quite rarely in Scotland, so it’s less useful for pollinators, although it still supports a lot of insects that use other parts of the tree.

Few would deny that it is the bright yellow blooming catkins which are the star of the show attracting honey bees, bumblebees and solitary bees in good numbers. Come early March it is worth keeping an eye out for willow and their eye-catching catkins. If there are any pollinators around you won’t be the only one impressed. This is one tree that can cast a magical spell in early spring.