The Hydrangea is a flowering bush native to Asia and the Americas. Hydrangeas are prized for their large clusters of colorful blooms.
While Hydrangeas have rather demanding moisture requirements, these bushes are generally hardy and make a great addition to any landscape.
Types of Hydrangea
There are several different types of Hydrangeas used in landscaping. Some varieties bloom on new growth, while others bloom on old growth from the previous year. These are the most common types seen in home gardens.
Also known as the Bigleaf, Mophead, or Lacecap hydrangea, this Hydrangea bush grows between six and 10 feet tall and wide. As one of the plant’s names suggests, this variety features large leaves, reaching a size of six inches long. Bloom buds set on branches between mid-summer and fall but do not bloom until the following growing season. The default flower color for this type of Hydrangea is pink but gardeners can turn the flowers blue by increasing the acidity in the soil.
Sometimes called the Smooth Hydrangea, this variety grows between three and six feet tall and wide. The blooms are either white or pink, with buds setting on new growth in the spring. Blooms will appear shortly after.
Also known as the Oakleaf Hydrangea, you can expect this Hydrangea bush to mature at a size of around seven feet tall and wide. The blooms can be white or a purplish-pink color. The buds set on old growth mid-summer to fall for next-season blooms. As the alternate name suggests, the bush features leaves that resemble those of the Oak tree.
Better known as the facile Hydrangea, this Hydrangea stands out among other varieties thanks to its cone-shaped bloom clusters. Most of the cultivars’ blooms emerge white and then gradually turn light pink as the flowers mature. The bush reaches a size of between 15 and 20 feet tall and wide if left unpruned. Blooms on this bush emerge on new growth each spring.
When to Plant Hydrangeas
Plant your Hydrangea bush either in the fall or early spring to allow the bush to establish a healthy root system. If you live in a climate where winter comes early, spring planting is recommended. When planting in the spring, wait until the ground has thawed and the last risk of frost has passed.
Where to Plant Hydrangeas
The three most important factors to consider when choosing a planting location for your new Hydrangea bush are sunlight, soil quality, and moisture availability. In Southern climates the ideal spot will receive morning sun followed by afternoon shade to avoid scorching the foliage. Hydrangea bushes planted in full shade may grow larger but will struggle to bloom as prolifically as those that receive more sunlight. In Northern climates, all-day sun is acceptable in most cases.
Moisture accessibility, whether it be rainfall or manual watering, needs to be adequate. Avoid planting your Hydrangea bush under a large tree’s canopy if you wish to rely on rainfall to water your bush. For large properties, do consider the logistics of getting a garden hose to your Hydrangea’s location as these plants require consistently moist soil all season to thrive.
The type of soil you plant a Hydrangea bush in will impact its success. Hydrangeas prefer soils that can retain enough moisture to sustain the bush but still provide enough drainage to avoid soggy soil. Avoid clay or sandy-based soils and instead opt for a loamy soil texture. Amending heavy soil with peat moss works well and sandy soil can be improved with the addition of organic matter, such as compost. Also, acidic soil will change the bloom color of some Hydrangeas from pink to blue. If this is a result you’re wanting, choose a site near, but not directly under, an evergreen tree. The falling needles from evergreens naturally increase the acidity of soil as they decompose.
For those living in USDA growing zones 7 or higher, Hydrangeas can be grown in containers if you wish.
How to Plant Hydrangeas
Once you’ve chosen your ideal planting location, it’s time to plant your new Hydrangea bush. Begin by digging a hole twice as wide as the bush’s current container and approximately two to three inches deeper than the pot is tall. Once the hole is dug, pour a two-inch layer of either compost or bone meal into the hole and spread it evenly over the bottom. Remove the bush from its container and squeeze the root ball to loosen the soil and roots.
Place the bush in the middle of the hole and spread out the roots as much as possible. Backfill around the root ball with the removed soil until the soil is even with the top of the root ball’s soil. Water the Hydrangea immediately to set the bush and increase the soil to root contact. Lastly, lay a two-inch-thick layer of mulch around the base of the bush, leaving a three-inch space between the base of the branches and the inner perimeter of the mulch.
Companion Planting with Your Hydrangea
Companion plants complement each other both aesthetically and, often, help keep each other healthy.
Shrubs that complement Hydrangea are Azaleas, Holly, Gardenia, and Boxwood. The evergreen foliage of the Boxwood and Azaleas add visual interest to the area year round. The Boxwood is also beneficial as it can be pruned to the perfect size to provide protection for the base and roots of the Hydrangea.
Choose shade-tolerant perennials to plant around the base of your large Hydrangea bush to add color and interest during the growing season. Hostas, Ferns, and Foxglove work well and will grow well in the shady area at the base of the bush. For smaller Hydrangea bushes that don’t create a shade area at its base, choose Daylilies, Salvia, or Dianthus.
If you prefer to change up the aesthetic around your Hydrangea each year, opt for flowering annuals to fill in the space and add visual appeal. Choose the shade-loving Coleus, Impatiens, or Begonias, or plant Petunias, Marigolds, or Zinnias for sunny locations.
How to Care for Your Hydrangeas
Consistent watering is the key to a healthy Hydrangea bush. During the growing season, water your Hydrangea one to two times per week until the ground is saturated but not waterlogged. In higher heat increase waterings if needed. During high temperatures, the leaves of the Hydrangea will wilt and curl. This is natural protection for the plant and not necessarily an indication the bush is dehydrated. If you’re concerned, check the Hydrangea’s leaves in the cooler evening temperatures. If the leaves are still wilted and curled then give the bush a thorough watering.
If your Hydrangea’s soil is already rich in organic matter then additional fertilizer is likely not required. Instead, boost the soil’s fertility in the spring by spreading a thick layer of organic matter around the base of the bush and gently work it in with a garden fork. Be careful not to damage the Hydrangea’s roots in the process.
To prune your Hydrangea properly, you will need to know if the bush blooms on old growth or new growth. If your variety of Hydrangea blooms on old growth, prune the bush once all the flowering has finished in the fall. For new-growth bloomers, prune in late winter or early spring. When pruning, always use sharp and sterile shears to avoid damaging your Hydrangea. Remove dead or damaged branches, as well as branches that are crowded or ingrown.
Overwintering Your Hydrangeas
In climates that experience long, cold winters, it is advised to provide protection for your Hydrangea plant to help them survive the winter. In the fall, before the first snowfall, wrap your Hydrangea bush with heavy-duty burlap. If the bush is sitting in an area that is exposed to strong winds, wrap and tie the outer branches before wrapping to provide extra protection and support.
Growing your own Hydrangea bush does require some regular maintenance but the results are well worth the effort. A healthy Hydrangea will produce big, beautiful blooms that will add beauty to your garden. Hydrangea blooms also make excellent cut flowers to include in your own floral arrangements.
Growing Hydrangeas FAQ
There are over 100 varieties of Hydrangea.
Common diseases affecting Hydrangeas include Botrytis Blight, Cercospora Leaf Spot, and Powdery Mildew.
In flower language, the Hydrangea symbolizes gratitude, grace, and beauty.
Yes, Hydrangea blooms attract bees, butterflies, and insect pollinators.