A Cold Climate Hydrangea

Hydrangea macrophylla ‘Endless Summer’ blooms on both new and old wood
The color depends on soil pH. My neutral soil produces the blue-pink pictured. Acid soils give a more blue bloom, and alkaline soils will tend to give more pink to the flowers.

I coaxed the mophead and the lacecap hydrangea varieties along with meager success in my garden, so when I saw the promises of “Endless Summer” I was hooked. It was advertised as a macrophylla that would bloom despite the cruel winter dieback of our cold climate here in Ohio. And it was “blue”! I’m as enamored of blue flowers as the next person.

A few years ago, after seeing an end of summer bargain on one, I bought ‘Endless Summer’ for my own garden. There was an empty place in the foundation planting, so there it was situated and deeply mulched. The photo collage above shows this years result. Admittedly 2009 has been a cooler and more moist summer than usual, but I think that with attention to watering during dry spells, this hydrangea is a keeper.

[The look]

The Hydrangea macrophylla are medium to coarse texture in form within the garden design. Their heart-shaped leaves are softly ridged, like old corduroy, in a lush green color. As a shrub, ‘Endless Summer’ forms a mounded shape with spaced heads of large, branched globose cymes (translation: full rounded heads made up of little flowerets). The effect is a luxurious bloom that easily makes a bouquet. The flower color ranges in variations dependent on soil acidity (the pH). Change from pink to blue by adding aluminum sulfate, conversely blue to pink by “tying up” aluminum by adding a bit of dolomitic lime. Be careful when adding chemicals to the soil, that you not create imbalances which could affect other plants nearby.

A three foot by four foot deciduous shrub, the hydrangea is grown for its flowers, and this one is chosen for its repeat bloom and hardiness.

Most garden soils have adequate aluminum, but the aluminum will not be available to the plant if the soil pH is high. -US National Arboretum

[The needs]

Plant in full sun to part shade, moist, but not soggy soil. Happiest in light shade and moist soil, increase moisture retention with organic amendments to build humus. Clay soils are already moisture retentive, but could get soggy and lead to rot; so incorporate peat moss when planting and mulch heavily ever after. Fertilize hydrangeas once or twice a year using a high potassium, low phosphorus fertilizer.

Although recommended for shady areas, remember that too much shade reduces bloom and planting under trees can be too much competition for a plant that needs both moisture and fertile soil.

[Growing notes]

Originally native to Japan, the blue macrophylla that gardeners such as my grandparents grew was the ‘Otaksa’ hydrangea introduced by Dr.Von Siebold. Ken Druse, in his book ‘Planthropology: The Myths, Mysteries, and Miracles of My Garden Favorites‘, tells the romantic but tragic story of how this shrub came by its name for Von Siebold’s Japanese lover.

Since the original species grew in “the coastal regions of the Japanese islands, especially the south coast of Honshu” they should be somewhat salt tolerant.

‘Endless Summer’ will wilt easily, even when well mulched it must have consistent moisture during dry spells. This means it is not a low maintenance shrub, although it seems immune from most plant diseases and maladies.

Propagate by cuttings.

Japanese print

[Fun facts]

Hydrangeas are beloved of interior decorators for big impact flower arrangements.

The blooms make dried and pressed flowers.

They are pretty, but don’t eat them .

Soil pH is a measure of the soil acidity or Soil alkalinity. An acid solution has a pH value less than 7. While a basic solution always has a pH larger than 7… Soil pH is an important consideration for farmers and gardeners ~ more info from Soil pH- Wikipedia

More Links:
Best FAQS page
NCSU Factsheet
Drying Hydrangeas
Mophead hydrangeas
Hydrangea print by Sumi-e Kazu Shimura

Related Posts:

• The Beautiful Annabelle
• Blue Flax, Linum narbonense
• Balloon Flowers Throw A Midsummer Party
• Alberta Spruce
• Viburnums: Plants for All Seasons