Growing Hydrangeas - Planting & Caring for These Stunning FlowersLearn about growing hydrangeas, including pruning and design tips, how soil plays a role in their color and which type is best for your garden
Not many garden shrubs can provide the punch of summer color that hydrangeas do year after year. Although most varieties prefer partial to full shade, there are selections appropriate for most gardening situations.
Hydrangeas are popular summer-flowering shrubs that are easy to grow and care for. Photo by: Joyce Vincent / Shutterstock.com.
There are hydrangeas available for zones 3-9.
The mature size of a hydrangea differs depending on the species and cultivar. Some are as small as 3-feet by 3-feet, while others can reach 15-feet tall and 12-feet wide.
Most hydrangea plants bloom best in part shade, but there are some that tolerate full shade and some that tolerate full sun. The amount of sun hydrangeas can handle depends upon your location—in areas further north they can take more sun, while further south they prefer just a few hours of morning sunlight.
Hydrangeas are commonly thought of as summer blooming shrubs, with some blooming earlier in the season and some blooming later (and if you’re lucky, possibly even into fall).
Types of hydrangea:
There are many hydrangeas to choose from, with a wide variety of characteristics. You can choose a standard-size hydrangea shrub, a smaller dwarf hydrangea or a taller tree-like type. You can also choose from four distinct flower shapes: lacecap, panicle, mophead or snowball. There are also types that bloom on old wood, types that bloom on new wood and types that bloom on both old and new wood, often referred to as “reblooming” or “remontant” hydrangeas.
Furthermore, you can choose from six different common species, which are as follows:
- Bigleaf or French hydrangea (Hydrangea macrophylla)
- Oakleaf hydrangea (Hydrangea quercifolia)
- Climbing hydrangea (Hydrangea petiolaris)
- Panicle hydrangea (Hydrangea paniculata)
- Smooth hydrangea (Hydrangea arborescens)
- Mountain hydrangea (Hydrangea serrata)
Compare the sizes, light needs and bloom time of the different hydrangea types and determine which ones meet your gardening needs.
One characteristic of hydrangeas that puzzles gardeners is flower color. Many hydrangeas will open one color and then change colors as they age. Additionally, the color of certain hydrangea flowers responds to the composition of your soil, turning blue, pink or purple. There are also white hydrangeas, green hydrangeas and even some newer introductions with red flowers.
Learn more about changing the color of hydrangeas.
Gently loosen the roots of your hydrangea before placing it in the planting hole. Photo by: ajlatan / Shutterstock.com.
Growing hydrangeas successfully starts with the planting process. It's all about timing, location and healthy soil.
When to plant hydrangeas:
Container-purchased hydrangeas should be planted in spring or fall. Make sure there is no threat of frost when you plant your hydrangeas.
Where to plant hydrangeas:
Keep reading for some suggestions on how to find the right spot for planting your hydrangea.
- In general, the best location for a hydrangea is a spot in your garden that receives morning sun and afternoon shade. If you live further north, hydrangeas will tolerate more sun (possibly even full sun all day).
- Make sure to account for the mature size of the hydrangea when selecting a spot for planting—give your plant plenty of room to grow.
- Pick an area of your garden that has excellent drainage. Amend the soil with compost if necessary.
- Do not plant hydrangeas beneath a tree—the root competition and lack of sunlight will prevent them from thriving.
- Avoid planting hydrangeas in exposed areas where gusty winds could snap stems.
How to plant hydrangeas:
To get your hydrangea off to a healthy start, amend your soil with up to 15% organic matter and an all-purpose slow-release fertilizer (use half of what is recommended). Plant hydrangeas slightly higher than they were in the nursery container (plant proud or high). The planting hole should be 2 to 3 times wider than the root ball to give the roots plenty of room for expansion. If the roots appear to be bound, loosen them gently before planting. Finish up by backfilling with the amended soil and then water well. If you are planting a grouping of hydrangeas, space them at least 3 feet apart (more if they are larger varieties).
Planting hydrangeas in pots:
When planting a hydrangea in a pot use a bagged potting mix rather than garden soil. Mix in a slow-release fertilizer and make sure to leave an inch to 1.5" of headroom between the top of the soil and the rim of the pot for watering. Make sure the pot you use has drainage holes and is big enough that your hydrangea has room to grow.
If you wait until spring to prune your mophead hydrangeas (Hydrangea macrophylla), be careful not to remove the new buds that are forming. Photo by: Dorling Kindersley ltd / Alamy Stock Photo.
Many hydrangeas don’t need major pruning. Most need just enough to keep them tidy by removing old flowers and dead stems, some trimming to improve the shrub’s structure or shape, or to open up the shrub to let in sunlight and air.
Flower head size can be related to pruning, as with more aggressive pruning, shoots will be more vigorous and flower heads will be larger and fewer. Less aggressive or tip pruning can result in smaller but more numerous flower heads.
How and when to prune depends on the type of hydrangea you are growing. You’ll need to determine whether your plant blooms on oldwood, new wood, or both before proceeding.
Learn more here: How to Prune Hydrangeas.
All hydrangeas like well-drained soil that is rich in organic matter. Soil composition can affect the flower color of H. macrophylla and H. serrata. Other varieties can tolerate a range of soil alkalinity.
Mulch with organic material annually. A slow release 10-10-10 chemical fertilizer with thorough watering before and after applying is also an option.
Hydrangeas like to be kept moist, but not wet. Don’t let them dry out. Container hydrangeas may need daily watering. Add mulch to help keep soil moist.
Diseases and pests:
Hydrangeas are generally not affected by serious disease or insect problems; however, many species may be susceptible to some bud blight, bacterial wilt, leaf spot, or mildew. Keep an eye out for aphids and mites, and treat as needed. Japanese beetles can be a problem on oakleaf hydrangeas.
Hydrangea not blooming:
There are a few reasons why your hydrangea might not be blooming as expected. This problem is most prevalent with types that bloom on old wood, or last year’s growth. First, you may have pruned at the wrong time and inadvertently removed the stems that would have produced flowers. Second, the buds may have been damaged by a hard frost. Some gardeners cover their hydrangeas during cold snaps if they think this may be any issue. Finally, the lack of flowers could be caused by too much shade or over-fertilizing.
Landscape Design Tips
Hydrangeas can play many roles in the garden, from hedges and screens to container plants. They especially shine in borders because they “play so well with others,” says Cheryl Whalen, head gardener at White Flower Farm. “But,” Whalen adds, “hydrangeas are also excellent solo performers,” which is good news for gardeners with small spaces.
- White-flowered selections create the illusion of snowballs in summer.
- Mass pink and blue types with similarly-colored garden phlox (Phlox paniculata selections) and lilies for a visual confection of candy colors.
- Blue selections look like sapphires against a gray wall or set alongside a slate patio.
- Bigleaf selections make imposing container plants - feature a pair in large urns.
- Panicle selections can be maintained as good-sized “trees” in large pots. Remember hydrangeas in containers will need extra watering.
- Oakleaf hydrangeas are the boldest and have the coarsest texture, lending visual strength to shrub borders and woodland plantings.
HYDRANGEA MACROPHYLLA ENDLESS SUMMER™
Without question the hottest hydrangea in the trade. Unlike most macrophyllas, ‘Endless Summer’ starts blooming early and keeps producing flowers (on new and old wood) throughout the season. New enough that its ultimate height isn’t well-documented; may reach 3 to 4 feet tall and wide.
HYDRANGEA PANICULATA ‘LIMELIGHT’
Similar to other ‘Grandiflora’ (PeeGee) types, ‘Limelight’ goes one step beyond the others with its big clusters of lime-green flowers that age to white. Expect a mature plant to reach 6 to 8 feet high by 6 to 8 feet wide. Hardier than many hydrangeas, to Zone 3.
HYDRANGEA MACROPHYLLA ‘MME. FAUSTIN TRAVOUILLON’
Somewhat smaller than loftier macrophylla types at about 5 feet tall, it flowers freely and over a long season. Blooms are dark pink in low-aluminum soils.
HYDRANGEA MACROPHYLLA ‘BRUNETTE’
Always richly colored, whether aluminum is available in the soil (flowers in shades of blue and purple) or not (flowers red). Not as tall or vigorous as many of its kin, making it a good choice for containers.
HYDRANGEA MACROPHYLLA ‘MARÉCHAL FOCH’
Though less cold-hardy than many macrophyllas, the profusion of saturated rose-pink mopheads of ‘Maréchal Foch’ makes it a favorite as an indoor plant in cooler regions.
HYDRANGEA QUERCIFOLIA SNOWFLAKE
Handsome oaklike foliage and attractively peeling silvery brown bark are reasons enough to plant any quercifolia, but this selection also features footlong, pyramidal heads of sterile flowers that look like stacked stars. Expect it to reach 8 feet tall and nearly as wide.
HYDRANGEA MACROPHYLLA ‘KARDINAL’
In the presence of aluminum in the soil, the intricate lacecap flower heads bear small fertile mauve flowers contained within a circlet of large, dark pink sterile flowers, as seen here. The entire cluster becomes red in the absence of aluminum. Less cold-hardy than other macrophyllas. About 5 feet tall.
HYDRANGEA MACROPHYLLA ‘GIMPEL’
Fully mature flower heads show a strong contrast of white fertile flowers and pink or blue sterile ones. Among the newer selections (introduced in 1986) and not as cold-hardy as some. Vigorous plants mature at less than 4 feet high.
HYDRANGEA MACROPHYLLA ‘NIGRA’
Although the pink or pale blue flowers are of some interest, grow this hydrangea more for its striking black stems. Extra fertilizer and routine removal of older shoots encourages stronger, darker new growth. Can grow 4 feet tall and 6 feet wide.
HYDRANGEA SERRATA ‘TOKYO DELIGHT’
White lacecaps gradually turn pink as the season progresses. Has an attractive upright plant habit, and the dark green leaves acquire red and purple shades in autumn. Spotted stems offer additional visual interest. Under 5 feet tall.
Although not obvious in this picture, Hydrangea involucrata bears pleasingly fuzzy leaves. These offer an attractive backdrop for the open, airy lacecap clusters of pale blue to pink-mauve fertile flowers punctuated by a few showier, sterile ones. To 5 feet tall and wide.
Floral Design Tips
- You don’t have to be an expert floral arranger—even just one stem of hydrangea can be a bouquet.
- For longer enjoyment, flower heads can be dried. Visit hydrangeashydrangeas.com for detailed instructions.
- For more floral design tips, see How to Use Hydrangeas in Bouquets.