Hydrangeas That Work

Joe Caputi

One of the foundations of my cut flower program is hydrangea, but not just any hydrangea. Because of our central Virginia climate, soil structure (sandy loam with very little clay), intense summer heat, and a tendency for drought (we are in a whopper of a 15-year drought, with no signs of it letting up) not all hydrangea varieties do well on this farm.

When I started my cut flower business nearly 10 years ago, I had dreams of row upon row of big, fat pompoms of blue, purple and pink hydrangea—Hydrangea macrophylla. So I planted them, hundreds of them. But they don’t do well here at all. The plants are big and robust at first, but have very few blooms—and by very few I mean possibly 10 blooms per 100 plants. Without constant irrigation, they stress heavily in summer. This is not a successful scenario, and by no means a dream-fulfilling one.

But that doesn’t mean hydrangea won’t grow on this farm—quite the contrary.

While I was planting all of those potentially magnificent macrophyllas, I was also planting Annabelles (Hydrangea arborescens) and Pee Gees (Hydrangea paniculata Grandiflora), with much better success.

Okay, so they weren’t those lush, gorgeous orbs of blue and so on, but they have their own place among the pantheon of great floral gods. Even more importantly, they’re green, one of the hottest and ongoing color trends in the world of cut
flowers.

While I had, and still have, a great passion for the Pee Gees, my attention shifted to Hydrangea paniculata Limelight for many reasons: They are hardy, outrageously fast growing, make great cut flowers, and are green.

Hydrangea arborescens (Annabelle), Zones 3-8
In the Zone 7A of central Virginia, Annabelle hydrangeas are productive. In May, plants produce lacy, brilliantly chartreuse blooms, which transform into wedding-white, very large pillows (up to 10-in. wide) in June and July. They finish in early August with a muted, papery green, almost dry flower head. Each stage is interesting and usable as a cut flower, a near perfect wedding flower.

Planting and Pruning:
Left on her own, Annabelle can get to a width of 6 ft. and up to 6 ft. tall, but that isn’t useful for cut flower production.
Annabelles should be planted 4 ft. on center in rows 6 ft. apart. I add a half-cup of Miracid to each planting hole, re-applying once after harvest. Early spring or early fall planting is best and less stressful on the plants.
Plants may be sited in moderate shade to direct sun, but in an intensely sunny location, flowers can burn if they aren’t harvested early during the blooming process. To achieve the late-blooming, papery-green flower heads of early September, plant in an area that receives only morning sun, and muted sunlight in afternoon, or apply a layer of 50% shade cloth if possible.

When I was first learning the cut flower business, I was taught to prune Annabelle back to the crown, nearly to ground level. I have since learned that less severe pruning assures a multitude of hearty blooms much earlier in the season. Pruning to a height of 12 in. to 16 in. is preferable. I simply measure the distance from my heel midway to my knee while standing next to the plant and cut just above the top node.

Postharvest Treatment:
As stems are cut, all leaves but the very top few are stripped in the field, and stems are immediately placed in a bucket of tepid to warm water. Once cutting is completed, they are processed by re-cutting the stems, dipping the base of the stems into a Quick Dip solution, and placed in buckets of fresh warm water with a solution of Floralife or Chrysal preservative. Average vase life is 12 to 18 days at a moderate room temperature of 68F to 72F (20C to 22C). Arborescens do not refrigerate well.

Hydrangea paniculata (Limelight) (Zones 4-8)
Similar to Hydrangea arborescens, plants of Hydrangea paniculata Limelight are vigorous growers, produce stunning and numerous bright-green flowers, and are extremely drought resistant. Blooms transform to a rosy champagne color when left to mature until August.

Planting and Pruning:
Plant Limelight 4 ft. on center in rows 6 ft. to 8 ft. apart. Add a half-cup of Miracid to the soil at planting, re-applying once after harvest.

Limelight can also be planted in moderate shade to direct sun, but perform much better under a 50% shade cloth, allowing blooms to open fully without burning. Fully opened flowers dry easily, lasting up to a year.

When properly pruned, plants produce several long canes (up to 24 per plant) with large oblong blooms. If left unpruned, they may become exceedingly branchy with up to 100 smaller, unimpressive flowers. That is not to say they aren’t usable in corsage work and smaller arrangements, but they don’t have the same stunning impact of the large, single-stem blooms. Pruning is done in mid April. Measuring down to the third node from the crown, prune just above the node.

Stem length can be up to 5 ft. on mature plants, but longer stems compromise hydration and shorten vase life. Cut no more than half the blooms on a first-year plant.

Postharvest Treatment:
Cut each stem to the desired length and strip the leaves in the field, immediately placing stems in a bucket of tepid to warm water. Once cutting is completed, processing is similar to that of arborescens. Average vase life is 12 to 14 days at a moderate room temperature of 68F to 72F (20C to 22C). All varieties of Hydrangea paniculata store well up to a week under refrigeration, with a vase life of seven to 10 days. Dry in a well-ventilated area with plenty of air movement from a fan.

For a nearly guaranteed extended cutting season, the combination of Hydrangea arborescens Annabelle and Hydrangea paniculata Limelight generously produces gorgeous blooms from mid May well into September. Few other flowers can boast such a claim. They look great in the landscape and grow vigorously under the harsh, hot and dry summers of central Virginia. They are the true workhorses of my cut flower program. GT

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Joe Caputi is the owner of and grower for Charlotte’s Garden in Louisa, Virginia.