All der year round

An excellent source of food for finches especially siskins, are the conelets of all three alder species found in the UK.  Common alder and grey alder produce large bunches of small conelets full of tiny seeds. 

(In the picture below the leaves are ivy and the bark is grey poplar)

Whereas the Italian alder has larger conelets but not so many in a bunch.

They are called conelets because they look like fir cones but alders are clearly not coniferous (bearing cones).  Here are some more Italian Alder conelets with the right leaves and bark, photographed in Vilner Lane Wood.

It's an old joke - or a way of remembering - that alder trees keep their conelets on into the winter until the new green conelets develop the following year so they can be recognised by having conelets on 'all der year round' (boom boom)