Do hydrangeas bloom all summer?

Only certain varieties of hydrangea growing in their optimal climates can bloom all summer. In ideal mild climates like Zone 7, choose “reblooming” varieties that can grow flowers both on old wood and new wood for the best chance at an extended blooming period. In addition to reblooming cultivars, you can mix different varieties and species to create a lovely show of flower clusters all summer long.

Do hydrangeas bloom all summer?

Whether or not hydrangeas bloom all summer depends on the variety and how they’re grown. A hydrangea plant can certainly bloom all summer if it is a reblooming variety and the winter has been mild. These plants are easy to grow and will provide you with a long season of colorful blooms.

Most varieties of reblooming hydrangea are either one of two hydrangea types (or hybrids of the two):

• Bigleaf hydrangea (Hydrangea macrophylla)
• Mountain hydrangea (Hydrangea serrata)

To ensure that your hydrangeas bloom well, ensure that your soil is well-drained and has good moisture. You also need to provide them with plenty of light. This is especially true for cold-climate gardeners.

Water your plants well during the day to keep from wilting in the hot summer months. You can also spread a layer of organic mulch to keep the soil cool and retain moisture. Some gardeners also fertilize their hydrangeas in the summer after they start blooming to give the plant more nutrition as it blooms and sets up the buds that will overwinter on the stems.

Reblooming hydrangea cultivars

Unlike most hydrangeas, reblooming hydrangea cultivars produce flowers on both old and new wood. Most reblooming hydrangeas are bigleaf hydrangeas (Hydrangea macrophylla) but there are also several reblooming cultivars of mountain hydrangea (Hydrangea serrata).

Here are some of the most popular reblooming hydrangea cultivars to look for if you’d like an extended flowering season:

1. Endless Summer hydrangea
2. Summer Crush hydrangea
3. Bloomstruck hydrangea
4. Tuff Stuff hydrangea
5. Blushing Bride hydrangea
6. Penny Mac hydrangea
7. Tiny Tuff Stuff hydrangea
8. Cape Hatteras hydrangea
9. Mini Penny hydrangea
10. Early Blue hydrangea
11. Blue Jangles hydrangea
12. All Summer Beauty hydrangea
13. Ayesha hydrangea
14. Tuff Stuff Red hydrangea
15. Cape Cod hydrangea
16. Red Sensation hydrangea
17. Fire Island hydrangea
18. Rhythmic Blue hydrangea
19. Shamrock hydrangea
20. Starlight hydrangea
21. Moonlight hydrangea

Many of the varieties above belong to one of these popular lines:

• Endless Summer hydrangea series from Bailey Nurseries (blue pots)
• Let’s Dance hydrangea series from Proven Winners (white pots)
• Tuff Stuff hydrangea series from Provien Winners (white pots)
• Seaside Serenade hydrangea series from Monrovia (green pots)

The ideal climate for a long re-blooming hydrangea season

In their ideal climate of Zone 7, reblooming hydrangeas tend to bloom reliably from early summer (May-June) through until the fall (September-October). In these climates, remontant hydrangeas truly do bloom all summer. Trimming off spent flowers will encourage the plant to rebloom, so be sure to deadhead regularly in the summer.

At the cooler end of their growing range, Zones 4-6, overwintering flower buds are often killed by cold temperatures and desiccating winds. In these colder climates, reblooming hydrangeas often only get the second round of blooms. The overwintering buds don’t make it to springtime, so the plant’s only chance to bloom is on fresh new growth. This delays the start of the flowering season considerably.

At the hotter end of their growing range, Zones 8-9, the summer weather often gets so hot in mid-to-late summer that the plants stop blooming. Avoid direct sunlight in the afternoon in these climates and site the plants in a cool spot with ample water if possible.

Blooming times for each popular hydrangea species

Different hydrangea species bloom at different times during the growing season. You can mix up different species to have some blooming in spring and other shrubs bloom in summer.

Here are the traditional blooming seasons by type:

• Smooth hydrangea: Blooms in summer on new wood
• Panicle hydrangea: Blooms in summer on new wood
• Bigleaf hydrangea: Blooms in spring on old wood
• Oakleaf hydrangea: Blooms in spring on old wood
• Mountain hydrangea: Blooms in spring on old wood
• Climbing hydrangea: Blooms in spring on old wood

Combining types for hydrangea blooms all summer

In a cooler climate where bigleaf hydrangea may not be able to flower on old wood at all due to the cold winters, choose a hardier species like oakleaf or mountain hydrangea for your spring blooms. Then you can plant panicles and/or smooth cultivars for summertime blooms.

Using different hydrangea varieties in your garden is a great way to add color to your summer landscape. These shrubs can grow at a variety of heights, bloom in several colors, and are easy to care for. They are also wonderful for creating long-flowering hedges.

As discussed above, recent hydrangea breeding developments have led to certain cultivars of bigleaf that can bloom on both old wood and new wood. This extends their blooming season from spring through to summer – but only in areas where the overwintering spring blooms aren’t killed by cold winters. They may not reliably bloom in spring in Zones 5-6. But since the new wood blooms are so long-lasting on these plants, they can last into fall and even overwinter on the plant.

Tips for getting lots of flowers on your hydrangeas

Hydrangeas are excellent for mass plantings, and their flowers last for weeks. However, they require some maintenance. They can be pruned to encourage new buds. They also need consistent moisture during the early years.

To grow hydrangeas easily, you should ideally have well-drained soil with a pH of 5.5 to 6.5. You can also add organic mulch to the area to help retain moisture and nutrients.

Direct sunlight is also key for flower formation. In hotter places, aim for morning sun and afternoon shade. Gardeners in more mild climates can usually have their plants in full sun as long as they are well-acclimated and well-watered. Certain hydrangea types, such as panicle hydrangeas, are more tolerant of full sun.

You can also fertilize hydrangeas with a granular or slow-release fertilizer, but the amount you need depends on the hydrangea variety you’re growing. The more nitrogen you add, the more lush the foliage will be.

Hydrangeas are great plants to attract pollinators. They can fill in a flower bed in just one growing season. They are easy to grow and maintain and can produce beautiful blooms in many different colors.