Cold Hardy Hydrangeas
When you live in zone 6, it sometimes seems as though all the best shrubs require milder climates. But that is not true of cold hardy hydrangeas. With some 23 different types of hydrangeas, you are sure to find hydrangeas for zone 6. The wildly popular, color-changing bigleaf hydrangea (Hydrangea macrophylla) is the most sensitive to the cold of all the varieties. But it still is hardy in zone 6. Bigleaf produces huge snowballs of white, pink, or blue flowers in early summer. These are the “magic” cold hardy hydrangeas that change blossom color according to soil acidity. However, bigleaf are known to flower sparsely in cold climates. That makes it important to think about good zone 6 hydrangea care. Take some steps to protect your bigleaf hydrangeas by planting them in a wind-protected area. You should also mulch them well with organic compost come autumn. If you are growing hydrangeas in zone 6 and you’d rather go with an even hardier hydrangea, take a look at panicle hydrangea (Hydrangea paniculata). Gardeners living in zones as cold as zone 4 can grow this beautiful shrub, sometimes referred to as tree hydrangea. Paniculata are not tiny plants. These cold hardy hydrangeas rise to 15 feet (4.5 m.) tall. Their flowers don’t change color, but you’ll love the huge, creamy-white blooms. Or go for the popular ‘Limelight’ cultivar for unusual green flowers. Oakleaf hydrangea (Hydrangea quercifolia) is an American native shrub and it thrives down to zone 5. That means that it is one of the great hydrangeas for zone 6. This hydrangea grows to 6 feet (2 m.) tall and wide. It offers flowers that start a soft green, then turns ivory as they mature, and finally fade to a rose-purple in July. If you are looking for fall color or winter interest, consider this hydrangea. Its large, oak-like leaves turn an arresting shade of cinnamon before they fall, and the exfoliating bark is lovely.
Zone 6 Hydrangea Care
Even when you pick cold hardy hydrangeas with growing zones that include your own, it pays to baby these shrubs, at least for the first few years. If you provide optimal zone 6 hydrangea care, your chances of success increase. When you irrigate, be sure that the soil is evenly moist. The flower bed soil must drain well, since the plants cannot tolerate standing water. Don’t prune unless absolutely necessary for the first few years. This includes deadheading. Another good tip for zone 6 hydrangea care is cold protection. Cover your new plants in spring and fall if the weather looks like frost. In addition, use a heavy layer of organic mulch over their roots until all danger of frost is past.
