If you time it right, you can start the hydrangea season with Hydrangea arborescens (smooth hydrangea) and finish it with Hydrangea paniculata (panicle hydrangea), enjoying those big, showy blooms from early June until fall. Easier said than done, right? Nope, growing hydrangeas is actually quite easy, but here’s the catch: You have to know which hydrangeas you have in your landscape and what makes it thrive.
That’s important because there are so many hydrangea species. Some require shade, and some require sun, some bloom on old wood, and some on new wood. So knowing what you have (or what you’re purchasing) is critical.
To help, we’ve listed the most popular hydrangeas, with a summary of the each plant’s cultural needs. If you still aren’t sure which hydrangea you have, take a picture of it in bloom, and the staff here at the garden center will identify it for you.
1. Mophead Hydrangeas (Hydrangea macrophylla)
Other common names: big leaf, or French hydrangea (different names for the same plant), and lacecap hydrangea
- Bloom type: Mopheads have large, globe-shaped blooms. Lacecap hydrangeas form a flat disc of flowers.
- Bloom color: White, pink, blue, or purple. Blooms can also change color depending on the soil type.
- Bloom time: June/July
- Sun/Shade: Morning sun until 1 or 2 pm, then afternoon shade
- Zone: 5 to 9
- Water: These are thirsty plants whose “big leaves” will wilt on a hot summer day, but perk up quickly after watering.
- Pruning: The best way to maintain them is to cut down to the first pair of buds below spent blooms immediately after blooming. The older varieties such as ‘Nikko Blue’ bloom on old wood, so if you prune in late fall or early spring, you just pruned your blooms off.
- Fertilize: Use Espoma® Holly-tone in early spring, and a bloom booster (Espoma® Rose-tone is a good choice) again in May, June and July for bigger blooms. Follow the instructions on the fertilizer bag.
- Because these primarily bloom on old wood, if a late spring frost comes, be sure to cover the plants to protect sensitive buds.
- Color can change from blue to pink or vice versa depending on soil conditions. Acid soils maintain a blue color while more alkaline soils a pink color. Using sulfur helps keep blooms blue, or lime helps keep blooms pink.
What About the New Hydrangeas That Bloom on Both Old and New Wood?
The newer series of hydrangeas such as Endless Summer, All Summer Beauty, and Let’s Dance, are zoned 5 to 9 and bloom on old and new wood. Because these newer hydrangeas bloom on both old and new wood, a late spring frost doesn’t kill all of your season’s blooms and, bonus, you get repeat blooms. Pruning these newer cultivars can be done anytime, but if you do so in spring, wait to remove dead wood until all the leaves have been pushed out. Morning sun, and afternoon shade are still best, and they have the same requirements for watering and fertilizing.
Lacecap hydrangeas require the same pruning that the mopheads do, which is immediately after blooming Hydrangea macrophylla ‘Horwack’ or pistachio hydrangea is taking the color of macrophyllas to new hues. Going from green to dark pink and deep red, this mophead hydrangea stays smaller, growing to 3′ x 4 to 5′.
2. Smooth Hydrangea (Hydrangea arborescens)
Other common names: famous for the ‘Annabelle’ hydrangea and, more recently, the ‘Incrediball’ or the ‘Invincibelle Spirit’ (the first pink smooth hydrangea)
- Bloom type: Its blooms are large, and globe shaped
- Bloom color: White or pink, and it does not change color with soil conditions
- Bloom Time: Early June/July through fall
- Sun/Shade: Full sun, slight shade
- Zone: 3 to 9
- Water: Thirsty plants especially when establishing; leaves will wilt in the hot sun without water
- Pruning: Cut back by a third in early spring to encourage strong stems and large blooms
- Fertilize: Over-fertilizing can cause floppy plants. Fertilize once a year in early spring with Espoma® Rose-tone
- Native plant to North America
The newer cultivars like ‘Incrediball’ (enormous flowers) have stronger stems, and ‘Invincibelle Spirit’ is pink. Both prefer full sun and will re-bloom throughout the season.
Hydrangea arborescens ‘Annabelle’ is an old favorite. It grows 3 to 5′ x 4 to 6′ and can flop when it rains. Pruning hard (cut back to 6”) in late fall or early spring helps to encourage strong stems and bigger blooms. It blooms on new wood. Newer cultivars like ‘Incrediball’ and ‘Invincibelle Spirit’ have bigger blooms (basketball size) and stronger stems.
Hydrangea arborescens ‘Invincibelle Spirit II’ is pink and supports the research to end breast cancer. Check out how this hydrangea helps support this cause.
3. Panicle Hydrangea (Hydrangea paniculata)
Other common names: peegee hydrangeas and ‘Limelight’ hydrangeas
- Bloom type: Large conical-shaped blooms
- Bloom color: White, or lime green fading to pink or dark red
- Bloom time: July/September into fall
- Sun/Shade: Full sun
- Zone: 3 to 9
- Water: Water well while establishing but it isn’t as sensitive to dry days as the smooth hydrangea or mopheads
- Pruning: Blooms on new wood, so cut back 1/3 in spring, but don’t overdo it; interior stems help hold up heavy blooms
- Fertilize: Once a year in early spring with Espoma® Holly-tone or Rose-tone is sufficient
Some of the newer cultivars like ‘Quickfire’ and ‘Fire and Ice’ bloom earlier in the season to give you longer bloom time in the garden.
Hydrangea paniculata ‘Limelight’ has been a best seller for years. It grows 6 to 8′ x 6 to 8′ and its lime blooms fade to pink. Its cone-shaped blooms are full and make great cut flowers. This is an easy hydrangea for beginners.
4. Oakleaf Hydrangea (Hydrangea quercifolia)
Of note: its leaves look like oak-tree leaves
- Bloom type: Large, pyramidal-shaped, open panicle blooms
- Bloom color: White, fading to pink
- Bloom time: June/July into fall
- Sun/Shade: Full sun to part shade
- Zone: 5-9
- Water: Does not like wet feet, and can handle drier conditions
- Pruning: This one blooms on old wood, so prune immediately after blooming
- Fertilize: Use Espoma® Holly-tone in early spring; once is sufficient
- Native, stoloniferous (has “runner” horizontal branches that can root) shrub with exfoliating bark
Hydrangea quercifolia are good hedges or border plants. They are a nice transition between the landscape and the woods. As suckering shrubs, they can reach heights of 5 to 8′ x 5 to 8′, though smaller cultivars like ‘Munchkin’ (3′ x 3′) are available, too.
While this list doesn’t include all the hydrangeas, (there are also the climbing hydrangeas, the mountain hydrangeas, and more), it gives a good start to understanding and including them in your garden.
If you have questions, our gardening experts are always happy to help!
