How To Care For Damaged Hydrangea. For example if you have an exposed site placing your hydrangea in a sheltered spot in the lee of your polytunnel for example can prevent frost damage. Hydrangeas may be just about everywhere but these pretty flowers take a little bit of care to grow into the big blooms you know and love.
Cover it with a plastic bag and mist it often to keep it moist. Gently loosen the roots then plant using plenty of rich soil. You should also take care not to place your hydrangea in a frost pocket.
Bigleaf hydrangeas have weak dormancies and their flowers start to bud quickly come spring so these varieties are the most susceptible to damage from frost.
Hydrangeas putting on a second flush of foliage are using stored carbohydrate resources to do it. Also add a couple of inches of mulch around the base to help hold moisture in and insulate the roots. Hydrangeas are sensitive to lack of water according to Niemiera and this has been an unusually dry spring through the end of April. They appreciate temperate climates.