Gardeners’ World celebrates the snowdrop and visits one of the world’s largest collections, lovingly nurtured in a suburban back garden and Monty gives tips on what to do once they have finished flowering.At Longmeadow it’s time to get dahlias into growth and, for inspiration, last summer we visited a field full of dahlias in Sussex to get tips from a professional grower.Nick Bailey revels in the beauty of magnolias and Monty has plenty of jobs for us all to be getting on with this weekend.