THE IMPORTED HYDRANGEAS
BIGLEAF HYDRANGEA
The bigleaf hydrangea (H. macrophylla), a Japanese native hybridized in France, is the most popular gardeners’ and florists’ hydrangea. The bigleaf hydrangea comes in two kinds: the mophead with bid round flower heads and a flatter, more open lace-cap form.
Picture: This Asian bigleaf hydrangea hybrid was giving to my mother many years ago as an Easter potted plant; it is kept small (under 3 feet) to fit the garden’s scale by pruning it back to 2 buds above the ground each spring. This particular hybrid changes color as it ages. Stamford CT July 2005
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Picture: Another bigleaf hydrangea at my mother’s. This one is known as “The Marc” due to it having been rescued from my friend Marc’s too shady yard. Stamford CT July 2005. It starts out blue with a creamy center, then goes full blue – the blue color indicating that the soil is the standard southern Connecticut acidic mix
Bigleaf hydrangea is the hydrangea that turns color depending on the soil pH: purple or blue in acidic soil, white or cream in neutral soil, and pink in alkaline soil. (This has to with the availability of aluminum in high PH acidic soils.) ,Some say that the bigleaf hydrangea’s fall leaf color isn’t significant but I think it’s nice. I also like the winter buds.
Unless you’re very familiar with hydrangeas, it can be hard to tell a smooth hydrangea from a bigleaf hydrangea, other than by the flower color. For example, where I live in Connecticut, we have acidic soil making the “default” bigleaf hydrangea color blue; so if I see a white hydrangea shrub with a rounded flower head, I can be pretty sure it’s a smooth hydrangea.
Picture: bigleaf hydrangea lace-cap form. Bedford Street Stamford CT August 2005
Like the oakleaf hydrangea, the bigleaf hydrangea is at the northern end of its range in zone 6, and is subject to winter damage. The bigleaf hydrangea is said to be an “old wood” hydrangea but again should be spring pruned, at least in the north.
The bigleaf hydrangea is a favorite sea-side and roadside plant since it is salt tolerant. It doesn’t like drought, though, so it shouldn’t be planted in full sun in a dry place.