Those of us in colder regions who aspire to grow Nantucket's famous blue Hydrangeas have our wishes granted. This new Mophead variety blooms on both old and new wood from early summer into frost on fast-growing shrubs with dark green leathery foliage. Acidify the soil to deepen the blue. 'Grenan'

Hydrangea is a valuable genus of some 100 species of shrubs and vines grown for their large and very showy flower heads. Hydrangeas are at their best in summer and fall -- quiet time for most woody plants -- and are worth having for that reason alone. For information on Hydrangea care, click on Growing Guide.