Virtually every well-tended garden is now going through its cycle of summer colour, but a certain flowering shrub is just around the corner, preparing to steal the show.
Hydrangeas, next to roses, are perhaps the most common deciduous flowering shrub in West Coast gardens. The macrophylla, or garden hydrangea, was introduced to England in 1736, and since then a whole series of exciting new varieties have been developed for the home garden.
When folks ask me to recommend a good vine for a shady north wall, my first choice is the climbing hydrangea, anomala petiolaris. This deciduous, fast-growing vine has four-inch-long, dark, heart-shaped glossy leaves. It has aerial rootlets that cling to virtually anything standing still and the plant itself will stretch to twenty feet or more, if left untrimmed.
Its foliage appears quite early in the spring and lasts well into the autumn. In my opinion, it almost qualifies as an evergreen vine. The real feature of this attractive vine, however, is its large, flat white flower clusters which grow to six inches across and resemble the lace-cap varieties.
This hydrangea is hardy to -25 degrees Celsius. which is surprising because of its lush appearance. It's a winner in any garden and will tolerate some sun, but the foliage is far richer in a more shaded location.
The flowering hydrangeas you see in fall gardens are most likely the heat loving P.G. varieties (P.G. is short for paniculata Grandiflora). You've probably seen some in tree forms as many have been grafted that way.
It is quite easy to select one strong branch and train it into a tree form. Believe it or not, this hydrangea is Prairie hardy, tolerating temperatures of -35 degrees Celsius. Given time, the plant can become almost a tree, stretching up to 12 feet in height, however most folks like to keep them trimmed back to around six feet to conform to most garden situations.
Its massive, pendulous cone-shaped flowers appear in mid-July and often last until late September when they take on a pinkish hue. The foliage of this fine garden plant also turns a rich bronze in fall, so it is a colourful accent in your autumn garden.
Most hydrangeas are very versatile, but they prefer moist soil and bloom far longer with some shelter from the intense afternoon sun. They are one great garden plant, and two or three varieties in a garden will be a welcome addition.
