Let’s Talk About Hydrangeas!

Hydrangea Paniculata Is Dependable And Very Winter-Hardy
Director of Horticulture, Les Lutz

As we move through the latter parts of July and into August, this species will start its show. Driving through various parts of the Cape, I see Hydrangea paniculata used to great effect and for good reason. This species is dependable. Always dependable. It can survive our winters with no worries and is considered one of the most winter-hardy of the Hydrangeas. It can also survive gardeners pruning with no problem as it flowers on current years’ growth. Even if you prune the plants hard in the spring, which is when many folks, tired of being inside all winter and itching to prune, take their pruning impulses to their hydrangeas, often to ill effect.

Best grown in organically rich, medium moisture, well-drained soils in full sun to part shade. This species is usually grown as a single-stemmed shrub but can easily be trained as a small single trunk tree or often as a ‘standard’, but is best grown as a large shrub.

‘Limelight‘ is probably this species most famous cultivar and has been in the trade for years. According to multiple sources this cv can grow to 6-8’ but realistically I’d put the height, without pruning, at more like 25’. But there are many, many new cultivars available. A quick search online and I’ve found 22 cultivars and I’m sure there are more. Of the major plant producers, Proven Winners has eight cultivar’s, Bailey Nursery has seven and Monrovia lists seven and each are introducing more each year.  READ MORE

Mal’s Favorites: Endless Summer

Hydrangea Video Series

Mal’s Favorites: Bluebird– hydrangea serrata

Mal’s Favorites: Endless Summer – hydrangea macrophylla + Pruning Tips

Mal’s Favorites: Bluebird– hydrangea serrata

Mal’s Favorites: Snowflake – hydrangea quercifolia

Mal’s Favorites: Lady in Red, Penny Mac & Twist-n-Shout – Hydrangea Macrophylla

Heritage Museums & Gardens Discovery Trail Fundraiser: Hydrangeas

The Display Garden is lovingly maintained by volunteers from the Cape Cod Hydrangea Society

Hydrangea macrophylla

A species found mainly in coastal regions of Japan. They do well in the Cape Cod maritime climate.

Colors range from white to pink, blue, or purple flowers, depending on the soil’s acidity. Blue flowers develop with acidic soil (a pH of 5.0 to 5.5) and pink flowers from alkaline soil pH (6.0 to 6.5). Aluminum sulfate can be added to acidify the soil, and lime to produce a more alkaline soil.

Hydrangea quercifolia

Commonly known as oakleaf hydrangea

Oakleaf hydrangea’s year-long parade starts in spring when dark green leaves unfurl. Depending on the variety, the oak-like leaves can grow up to 12 inches wide. Flower buds form long, cone-shaped clusters that crown summer landscapes with color. The elegant clusters combine large, showy florets with small, budlike flowers. Unlike mophead hydrangeas, soil pH doesn’t affect the color of oakleaf blooms.

Hydrangea paniculata

Originated in the Asian mountains in high elevations

Very cold hardy from zones 3 to 8 and prefers full sun; the most drought tolerant of the species.

  • Growth Pattern: typically strong growers, 5 to 10 ft. plus height & width in bush form; great specimen plants as standards (tree form)
  • Very long-lived; some plants are 100 years old
  • Flowers on new wood (buds form in the spring)
  • Bloom color unaffected by soil pH

Panicle blooms feature clusters of flowers on a branch and typically open white with maturing shades of lime green to pink to mauve, flowering
from mid-summer to mid-fall.

Hydrangea serrata

Commonly known as mountain hydrangea

A hardy species of Asian mountain origin, growing in the
forest understory. Cold hardy from zones 5 to 8, prefers shadier locations – at least a half-day of shade; prone to leaf spotting in high sun locations.

  • Hybridizes well with h.macrophylla; often utilized in newer rebloomers
  • Growth Pattern: Upright bush of rounded habit, 2 to 6 ft. height & width
  • Mostly delicate lace cap flowers with only a few mophead choices; lace caps feature a set of smaller inner fertile blooms and larger colorful outer petals
  • Blooms early in summer on old wood (buds form in the fall) with slightly subdued bloom color range – whites, pale greens, pinks, blues and some reds depending on soil pH and cultivar

July 9 – 18, 2021

The Cape Cod Hydrangea Festival is an annual celebration of the region’s blue, pink, and white signature flowers and everything gardens on Cape Cod! This ten-day festival’s main attractions are the daily tours of private gardens, each designed and maintained by the individual homeowners and carrying a unique charm. You are sure to enjoy such eclectic spaces, not to mention the good feeling of supporting a variety of local nonprofits which will benefit from the proceeds of each tour.

Recent Garden News & Blogs