There are many misconceptions about the hydrangea, starting with its name. It is widely assumed that this name expresses a need for more moisture or hydration than the average plant. But this assumption is incorrect. Although the first part of the word (hydr-) does refer to water, the second part (-angea) is derived from a Greek word for vessel. Taken together, the two parts of the word refer to the shape of the flower buds before they open, a shape similar to that of an ancient receptacle used for carrying water. Yet, etymology notwithstanding, the hydrangea is still more water needy than typical garden fare.
Incidentally, the “range” in hydrangea is also found in the word angisoperm, which means seed vessel. It refers to the classification of the vast majority of flowering plants whose seeds are contained and protected in vessels, from pods to pits to capsules. By contrast, a gymnosperm, meaning naked seed, refers primarily to conifers whose seeds are borne in between the scales of pine cones, for example, but are not contained within any type of vessel. Angiosperms are an evolutionary advancement since the development of vessels for holding seeds offers a measure of seed protection — and thus insurance for another generation of sprouts — that gymnosperms lack.
There is also a misconception regarding hydrangea toughness. While it’s true that the classic mophead hydrangea (Hydrangea macrophylla) cannot grow in the Antelope Valley but will do fine anywhere south of that area except on exceptionally cold nights, climbing hydrangea (H. petiolaris), smooth hydrangea (H. arborescens) and oakleaf hydrangea (H. quercifolia) can all withstand winter temperatures down to 10 degrees. Peegee hydrangea (H. paniculata) will even grow in Alaska and is extolled by Naomi Slater, author of the newly published “Hydrangeas” (Gibbs Smith, 2020) as follows: “H. paniculata is another hardy species, and it is as handsome as it is trouble-free. The pointed flowers are often spectacular and can be dense or airy, depending on the cultivar. It tends to form a large shrub or even a small tree, potentially reaching 20 feet in a favorable site. … It is unfussy about soil; it naturally prefers … good drainage with plenty of moisture, but if what is on offer is heavy clay or unpromising pebbles, it will make the best of the situation as long as it is not waterlogged, and it will also put up with drought.”
It is worth stopping for a moment to linger over oakleaf hydrangea, a sprawling plant that is ideal for locating on a shady slope or under trees since it will spread out and cover the ground in rather rapid fashion. Slater describes it in these words: “Native to south-east America, it has panicles of white flowers that form erect spires or cascading avalanches. These are set off by the lobed foliage, which is an attractive green in summer but really comes into its own in autumn, when it takes on tones of copper, crimson and rich, inky purple.” This species is slowly gaining in popularity in our part of the world and I can attest from personal experience to its carefree growth and durability.
In Southern California, hydrangeas of every description do have one weakness and that is exposure to direct afternoon sun. Such exposure will invariably fry the plants. Eastern exposure is ideal but northern exposure with good ambient light is also acceptable. And exposure in any direction is fine as long as there are shade-giving trees overhead. Much is made of hydrangea’s above-average water requirement but a constantly maintained two-inch layer of mulch, kept clear from stems, will stretch the interval between waterings.
Another misconception regarding hydrangeas is the idea that, when it comes to color, they are either pink or blue and occasionally red. But there are also a large selection of bi-color varieties that are more than worthy of our attention. Nowadays, almost every time I visit a nursery, it seems like I am looking at hydrangeas for the first time with so many new varieties available. Hydrangea angustipetala ‘Golden Crane’ is a lace cap hydrangea whose white and gold flowers emit a perfume — unusual for a hydrangea — that will permeate the air throughout your garden.
Naomi Slater’s book contains important guidelines for success at cutting hydrangea flowers for vase arrangements. “Take a clean bucket of cold water with you to the plant and cut nice, long stems straight into it … Flowers wilt when they are very soft and fresh, so … choose the older flowers that are fully expanded with petals that look more papery. . . When you get back indoors, trim the bottoms off the stems under the water, cutting at an angle of about 45 degrees … Strip some or all of the leaves from the stem … Leave in a cool and shady place to have a nice long drink, for at least a couple of hours … If you discover that your flowers have wilted … don’t panic. Strip leaves off and immerse the entire thing, flower heads and all, in room-temperature water. Leave them for several hours to rehydrate.”
Slater extols the beauty of hydrangea flowers as they fade. “They become newly beautiful,” she writes, “assuming desirable silvery shades or evolving a … palette of blue, pink or green as they dry. Even when fully brown, or skeletal, they are exquisite in autumn flower arrangements, combined with seasonal leaves and seed heads.” To create everlasting bouquets from these blooms, she recommends this procedure: “Once again, don’t cut them too fresh – young flowers will wilt and won’t hold their shape. But later in the season, as they harden up and become papery, they are far more resilient and can be harvested with impunity. Simply cut the mature bloom on a long stem, then arrange in a dry vase or hang upside down in a cool, dry place. The flowers will dehydrate but lose none of their beauty, and last for many months.”
Tip of the Week: To propagate hydrangeas from softwood cuttings, Slater’s technique is as follows: “You do this in spring and early summer, by cutting a new, flexible shoot, and trimming the bottom to just below a leaf node. You then remove the growing tip and most of the leaves and drop it into a premade hole in a pot of gritty, free-draining compost. (You can dip the base in rooting hormone first, if you wish, but I never do.) Cover the top with a plastic bag to create a humid environment and place in a bright place out of direct sunlight. Roots should develop in 6–10 weeks, after which the plant can be potted up.”
For more information about plants and gardens, visit Joshua Siskin’s website at www.thesmartergardener.com. Send questions and photos to joshua@perfectplants.com.
