COLUMN: Hydrangeas are stealing the show this summer

Flowering shrub adds a bright burst of colour to the garden

  • Jul. 23, 2016 6:00 p.m.
Hydrangeas add a burst of colour to summer gardens.

Hydrangeas add a burst of colour to summer gardens.

Gardening by Brian Minter

Our gardens are now going through their cycle of summer colour, but a certain flowering shrub is stealing the show. Hydrangeas, next to roses, are perhaps the most popular deciduous flowering shrub in West Coast gardens.

The “macrophylla” – “garden hydrangea” – was introduced to England in 1736, and since then a great many 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 glossy dark heart-shaped leaves. Its aerial rootlets cling to virtually anything standing still, and the plant itself will stretch to 20 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 that grow to six inches across and resemble the lace-cap varieties. This hydrangea is hardy to -25°C, which is surprising because of its lush appearance.

A winner in any garden, it will tolerate some sun, but the foliage is far richer in a more shaded location.

The flowering hydrangeas you see in summer 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.  I

t 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°C. Given time, the plant can become almost a tree, stretching up to 12 feet in height, but 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 an autumn garden.

“Little Lime,” one of the new shorter varieties, turns cream then multi-coloured. I love it for those sunny locations where a more compact plant is needed.

The most compact of all are H.p. “Bombshell” and “Bobo,” growing only three feet high and wide and blooming from July through to frost with stunning pure-white blooms.

“Little Quick Fire” is another new variety that comes out white, then immediately turns a deep pink and holds that beautiful colour to the very end.

The show stealer, however, has to be H.p. “Vanilla Strawberry” with its stunning white flowers that are almost immediately infused with red, creating a “wow” sensation in any garden.

“Lace Cap” hydrangeas have certainly drawn the most interest during the past few years. They are called “Lace Cap” because a cluster of sterile flowers in the centre is surrounded by large florets of traditional hydrangea blossoms.

The effect is really quite charming, and in shady locations they seem to outlast the “macrophylla” or common varieties.

Like the big-leafed hydrangeas, however, the blossoms will turn a beautiful sea-blue in acid soils and pink or reddish-purple in chalk soils.

Remember, you can change their colour by adding lime to keep them pink or aluminium sulphate to make them blue. There are now white “Lace Cap” varieties that look classy and elegant in any setting, and they do not change colour. Take a look at all the new varieties now available – they will amaze you.

One of the lesser-known hydrangea varieties is the “quercifolia” or “oak-leafed” hydrangea. This handsome shrub has rather large leathery leaves resembling oak leaves, and it grows to about six feet high.

This is a great plant for heavily shaded areas because its creamy white flowers, which appear in June, brighten up those dull spots, and its foliage, which turns a bright scarlet-crimson in fall, is really outstanding.

Unfortunately, this oak-leafed variety is often quite hard to locate in nurseries.

For small-space gardens, there are now several true dwarf varieties that stay within the three-foot range. Pia, Winning Edge and Pink Elf are some of the cutest little garden gnomes you’ve ever seen!

The truly big news is the first ever “macrophylla” type that blooms on new wood. For those buds that get frozen out in a bad winter, and for those of us who prune our hydrangea to the ground each spring and get no blooms, “Endless Summer” is the answer because, amazingly, it blooms beautifully on new growth.

The new double varieties from Proven Winners and Ball Ornamentals are really quite something as well, offering an entirely new look. They, too, can be blue or pink depending upon the pH level of the soil.

They are in bloom now, so take a look at these beauties. Two of the most unique, Green Star and Pistachio, are unusual blends of lime and pink that continually change.

Perhaps the most revolutionary hydrangeas now creating a sensation are nine varieties belonging to the “Everlasting” series. These compact (three to four feet) plants are repeat and continuous flowering. What I really love about them is that the older blooms, instead of deteriorating, become infused with green, adding a whole new element to this stunning series.

Most hydrangeas are very versatile, but they prefer moist soil and bloom far longer with some shelter from the intense afternoon sun. They are great garden plants, and two or three varieties in a garden will be a welcome addition.