Let me introduce you to my colorful friend LEONA . . . the acronym for five types of hydrangeas that will give you blooms for half the year or more: Limelight, Endless Summer, Oak Leaf, Nikko Blue, and Annabelle.
Hydrangeas are native to the Appalachian region of the U.S. and to the islands of Japan. H. quercifolia (Oak Leaf) and H. arborescens (Annabelle) are the only two North American natives; these species have made the Southeastern U.S. and Appalachia their natural habitat, growing from Florida to Pennsylvania in pockets of shade, in understory plantings, forest scenes, and on river banks. Gardeners in zones 6–9 can grow hydrangeas with ease.
In zones 7 and 8, blooms will stretch from May to October if you remember LEONA and site plants well. In my Georgia garden, Oak Leaf hydrangeas start blooming in May. After Oak Leaf, Nikko Blue and Endless Summer kick in, along with Annabelle. All three bloom close together, but the Nikkos turn green and shades of aqua after their classic blue shade, and may even show coral, rust, and chartreuse.
Not sure which zone you live in? Look up your USDA Hardiness zone.
Endless Summer blooms multicolored on each plant, with blues, pinks, and lavenders. Endless Summer will blossom again well into summer to finish up in the fall. (I count on their russet, coral, and aubergine blooms for autumn arrangements.) Annabelle blooms hard through June, and then the white flowers turn chartreuse green for added color in July and August. Limelight, a new offspring of H. paniculata, provides the grand finale from July through September. Creamy white panicles turn lime-green, with coral-pink edging.
As cut specimens, hydrangeas are a mainstay in floral décor. (Although the blooms of some hydrangea and viburnum—“snowball bush”—species resemble one another, the hydrangea is the better cut specimen, as its blossoms last longer.) Large, spherical, and colorful, hydrangea blossoms add drama to arrangements, and are dependable for months after they’re dried.
When you cut blooms, do so early in the morning, then allow the cut stems to condition in warm water before your handle and arrange them. A sharp, angled cut allows more surface area to be exposed on the stem, so that more water can be absorbed. Ask your floral supplier for a product called Hydraquick, which helps open the vascular tissue for greater water uptake.
In the garden, native soil amended with rich organic matter is the foundation for flourishing hydrangeas. Sunlight is key for bloom quality and quantity. For those of us in zones 7 and 8, Limelight, Oak Leaf, and Annabelle (or the paniculata and quercifolia species in particular) tolerate exposure to sun with plenty of water, but in the South these plants appreciate some high shade and solar relief, flourishing in spots with morning or late afternoon light. Though shade-tolerant and even shade-appreciative, hydrangeas, like all flowering plants, do require sufficient light to produce blooms.
The amount of water they need depends on the amount of sunlight: in full sun conditions, these plants need regular watering for hydration, leaf rigidity, and flower fervor. A hearty soaking two to three times per week ensures thorough watering of the roots.
The soil’s pH—whether it is naturally acidic or alkaline—is a major factor in cultivating hydrangeas. A more acidic soil, with a pH less than 7, keeps the blooms blue, especially with H. macrophylla cultivars such as ‘Nikko Blue’ and ‘Endless Summer’. A basic or alkaline soil with a pH greater than 7 will bring you pink and red blooms. To change bloom color, you may use aluminum, applied as aluminum sulfate. Coffee grounds, vegetable peels, and pine bark will mildly change pH. Adding lime de-acidifies soil, making it more alkaline. Acidic fertilizers do the opposite. By playing around with these, you can broaden the palette into jewel tones including amethyst purple, lapis blue, and peridot green. Given pockets of nutrients in soil layers, you can have multi-colored flowers on the same plant.
Hydrangeas root very easily. Simply stick cut stems into potting soil or directly into garden beds. Prune your hydrangeas twice a year, once during dormancy (I use Valentine’s Day as my benchmark, and remove spent flower heads and thin stalks at this time), and again during bloom—when you cut for arrangements. Canes removed during dormancy can be used for propagation; in mild climates, just stick the stems in the ground. Cutting during bloom encourages new growth and further bloom.
From the daintiest of lacecaps to the massive panicles of mopheads, hydrangea blossoms are spectacular grace notes in the garden. Plant wisely and you’ll have lots of bloom time as well as a year’s worth of table centerpieces.Published in: Old-House Interiors September/October 2010