The dieback you see on your ivy is likely not from a disease if the plants were healthy going into winter. Few disease problems develop during the dormant season. As a broadleaf evergreen, English ivy is susceptible to winter foliage injury. Severe leaf injury can occur in response to sudden drops in temperature or drying winter winds, which can cause the leaves to turn brown and drop from the plant. Check to see if the ivy is still alive: Scratch the woody stem with your fingernail. If the stem just below the bark is green, it’s alive. The ivy should leaf out again this spring from its dormant buds and regrow to fill in your ground-cover bed. Later this summer, cut out any dead vines that have not recovered.