Few plants are more vibrant than the hydrangea. They grow easily in various climates around the country, making them as popular as they are colorful. Follow these steps to learn more about hydrangea varieties and how to successfully incorporate these beautiful flowers into your landscape.
Originally imported from Asia, hydrangeas exist in many varieties in the US. Hydrangea macrophylla, which includes mophead and lacecap types, happens to be the most popular variety found in gardens. Most mopheads grown today are blue or pink (with a few white varieties), while lacecaps are much more widely grown, their flowers looser, creating a more graceful and subtle visual effect.
There are two species of hydrangea that are native to North America. Oakleaf hydrangea (Hydrangea quercifolia) has huge clusters of cream-colored flowers that last into summer and turn a dusty pink while the foliage turns burgundy red in fall. Smooth hydrangeas (Hydrangea arborescens) are the second species, with small domes of pretty white or pink flowers. All varieties exfoliate bark in shades of tan and cinnamon.
There is even a hydrangea that climbs to more than 50 feet. This slow-growing hydrangea has sturdy stems that will climb a post or brick wall, clinging with small aerial roots. It features flat-topped clusters of white flowers in early summer while the flaky tan bark provides interest in the winter landscape. Climbing hydrangea tolerates full sun in the northern part of its range, but is somewhat intolerant of the hot and humid conditions of the Deep South. While somewhat slow to establish, it grows quite vigorously once it does.
For the most part, hydrangeas like morning sun and afternoon shade. Climbing hydrangeas and oakleaf hydrangeas tolerate more shade, and the lacecap and panicle hydrangeas prefer more sun. To start, plant hydrangeas in rich, well-drained soil where they will receive adequate moisture. A bit temperamental in early stages, the roots will rot in heavy or water-logged soils, but they will wilt if conditions are too hot and dry. Once established, hydrangeas will thrive for years to come. For optimal growth, feed in the spring with a slow-release plant food, such as Miracle-Gro® Shake ?n Feed Flowering Tree & Shrubs Continuous Release Plant Food.
You may notice varying color changes in some of your hydrangeas. For Hydrangea macrophylla, the flower color will change from blue to purple to pink depending on the soil pH and the amount of aluminum present in the soil. To make your hydrangea flowers blue, add aluminum sulfate and make sure the soil is around pH 5.4. There are also some varieties that are more likely to stay pink or blue independent of soil conditions.
A little maintenance goes a long way. For hydrangeas that produce flowers on new growth such as panicle hydrangeas and smooth hydrangeas, it's best to cut them back in fall or winter. These hydrangeas generally bloom in mid-summer. The spring-flowering hydrangeas like the mopheads, lacecaps and oakleaf hydrangea bloom on old growth. They should be pruned after the flowers begin to fade but before next year's flower buds are set. To be on the safe side, prune before August. A good rule of thumb for all hydrangeas: you can rejuvenate the plants by cutting back some of the older, thicker stems at the ground. Enjoy the blooms.