Yesterday, in the rain, I visted the gardens of Melanie and Ray Poudrier and paid special attention to their collection of heaths and heathers. These two evergreen shrubby plants are often mentioned together in the same breath, but I never really knew how to tell them apart until Melanie made me look at the foliage closely. Heaths and heathers are both members of the Ericaceae family, but heath of the genus Erica has needle-like foliage. The foliage of…