Cutline quote: “Oakleaf hydrangea’s white flower heads age beautifully to burgundy.”
It would seem that the nation is in the grip of hydrangea mania. Sales campaigns for new introductions are planned and executed almost like military campaigns, q.v. the blue pots and logo of ‘Endless Summer.’ Consequently, sales of hydrangeas of all species and varieties are booming, and not least on Martha’s Vineyard. The evidence is everywhere that the Island is enjoying a hydrangea love affair of immense proportions.
Is there another plant whose blooms are more anticipated or more closely inspected, or whose coloration is more discussed?
Due to unexpected weather patterns, there was no way to prune hydrangeas correctly during the spring of 2015. Didn’t matter if one waited, or did not wait; there were so many bud-shriveling temperature shocks that garden owners all over the Island questioned whether their gardeners were pruning their hydrangeas incompetently and incorrectly.
This makes a great selling point for the newer hydrangea types of the ‘Endless Summer’ sort, which form flowering buds on old wood as well as new, throughout the season. If a temperature shock aborts buds formed on last year’s growth, replacements form shortly.
Now that we are in August, aging effects taking place on hydrangea flower heads are changing their coloration to the subtle and artistic colors we now see. The “petal” part of the flower actually turns and hangs upside down, and the deeper colors form on the undersides.
Everyone’s favorite, the mophead hydrangeas, H. macrophylla, may form new flowering buds after a light pruning. H. arborescens cultivars such as ‘Annabelle’ may do likewise, but most of the lacecap types bloom once only, after which the flowers age. Hybridizers are working, however, to breed a lacecap with continuously forming flower buds.
As the name hydrangea would indicate, hydrangeas are water lovers. The leaves of mopheads and lacecaps hang limply and they look very sad indeed, if grown in full sun or hot locations. Yet one sees this commonly, hydrangeas planted in baking locations: front of buildings, alongside asphalt streets, in planters outside storefronts. They look miserable! Partial shade is best for flower bud initiation, performance, and maintenance.
Drought-stressed hydrangeas are far more liable to be browsed by deer, at a cost of lost flowers. Either install them with a permanent drip line, sort of like a hydroponically grown plant, or avoid such locations altogether. Using good fertile soil that is free-draining and laying a temperature-moderating mulch are good cultural practices for these plants, which put out lots of energy in producing new canes and oversize foliage, but do not like soggy soil.
Or plant instead the frothy yet coolly elegant, white-flowered panicle hydrangea, H. paniculata grandiflora (“peegee” hydrangeas), which may be grown in full sun. These are gracing gardens all over the Island right now and, while different from a blue or pink mophead, are glorious and graceful, equally an icon of summer with their H. macrophylla cousins. Flowers of peegee hydrangeas also age beautifully, some, such as ‘Pinky Winky,’ having been selected for this trait.
I have so far failed to mention the oakleaf hydrangea, a North American native hydrangea of an entirely different species. Bold in texture, gorgeous for fall foliage color, this plant is a study in strong texture and form: white cone-shaped flower heads aging to burgundy in a good year, and oversize dimpled leaves mimicking an oakleaf shape. Plant them in partial shade, with the same humus-rich, well-draining soil that mopheads and lacecaps enjoy.
Mopheads, ‘Annabelles,’ and oakleaf hydrangeas encompass but a few members of a large family. Put Michael Dirr’s “Hydrangeas for American Gardens” (Timber Press, 2004) on your Vineyard coffee table and watch your friends reach for it; it contains cultivar info about the above and all their relatives, with many excellent photos and more information.
In the garden
The fair will be underway by the time this column sees print. See you there.
Meanwhile, sowing successional crops must be underway in order to see results before light levels diminish in fall. Good fall crops include beets, radicchio, carrots, Swiss chard, greens of all sorts — brassicas, spinach, lettuces — peas, and edible pod peas. Depending upon an individual garden plot’s siting and light levels, another crop of bush beans may yield well.
Most clumps of daylilies will look better if de-stalked and dead-leaved. Some, such as ‘Stella d’Oro’ and those with ‘Returns’ in their names, may be completely cut back; fresh new foliage will sprout. Cut back spent growth of biennial plants such as lychnis, lunaria, and foxglove; leave clustered basal leaves if any. The seedheads may be laid or shaken around the garden to produce future seedlings.
When cooler weather and rains come, many perennials will flush new growth and flowers if cut back or deadheaded now. Examples include coreopsis, nepeta, phlox, and geraniums. Remove deadheads from platycodon, butterfly weed, echinops — and religiously deadhead annuals.
Top up mulch and attend to watering. I had two nasty surprises at my place with new plants that were a little out of the way; it is shocking how little time it takes for significant damage to occur during drought. (I hope they will claw back now that I have them on my radar.) All recently planted trees and shrubs are vulnerable for a year after planting.
Feed containers with slow-release or soluble fertilizer — the middle number, phosphorus, should be high to boost blossom production. Watering is necessary almost daily during these blazing days. Once the plants dry out and wilt, they split open and the leaves yellow. At that point it is difficult to bring them back up, but you can trim back the growth somewhat, dead-leaf, and, after rehydrating, try a weak feed.