Feature Article Managing Hydrangeas in the Delaware Valley By Michael Bowell olks who visit my garden in native to Japan) were at the FMalvern (Charlestown Twp), Chester Jersey Shore and or as potted County, PA, know that I love and flowering plants on Easter and grow several species and cultivars Mother’s Day, complete with of hydrangea. I enjoy them for their foiled pots. I remember the varied colors and forms and often drive through Margate City use them as cut flowers and branches when the hydrangeas were at for weddings, party work, and vases. their July peak in the central We also dry them to use in fall and traffic islands of the main winter arrangements for our Create A thoroughfare, and abutting the Scene clients, frequently embellishing guesthouses of Ocean City photo ©Simple their faded blossoms with floral paint Hydrangea paniculata ‘Limelight’ flowering in and Cape May, NJ. Like many matching their original colors. At early August. The green buds open to white folks, I also recall hydrangeas Christmas, we spray some with gold and eventually color up to shades of pink , green planted from those foiled holi- paint for decorating mantles, wreaths, and burgundy in late summer, persisting well day pots growing to great size and trees, or as I say, “We grow past frost. They are available in both shrub and in our gardens, with their vigor- standard form. ‘em, guild ‘em, and sell them to the ous green growth and sparse goyem!” next, followed by the arborescens and flowering, foiling our dreams I am frequenty asked for advice macrophylla types in the garden, and of flower-laden shrubs. It made no about their care, from pruning to color finally the paniculata cultivars, which sense to me at that time, but I learned change, and for the most reliable vari- last through October. If you count later that those plants were potted up eties for the Delaware Valley. Viburnum macrocephalum1 (Chinese in the greenhouse and, like the plants Hydrangeas, at least the four Snowball Viburnum), which many we carry over in the cold frames each major groups discussed in this article, think of as hydrangea, I have hydran- winter, had already gone through a generally begin their show here in late gea-like flowers from April through period of dormancy. They are destined May when the containerized hydran- October, and dried flowers through the to flower when they break dormancy geas (all macrophylla types that have winter holiday season and beyond. as the weather warms and the days been protected in cold frames over Like most locals, my first memo- grow longer. winter) commence flowering.The ries of hydrangea (Hydrangea macro- Many of the cultivars that are used oakleaf (quercifolia) varieties are phylla, aka the mophead hydrangeas, in hothouse production are bred for flower size, style, and color and are Michael's Tips for Painting 1 Be wary of the confusion of common not reliably winter hardy in our gar- Use floral paint, many colors available at names...hydrangea and viburnum are both dens. Their wood dies to the ground craft stores. deciduous shrubs. The snowball hydran- in our winters, which are more severe gea (Hydrangea arborescens) belongs to Dip in paint if trying to highlight edges. than the coast and its beaches. Al- the Hydrangeaceae plant family, while Spray outdoors, be sure flower surface is though they recover quickly from their dry. the Chinese snowball viburnum (Vibur- base each spring, the older wood from Use multiple colors and layers for a more num macrocephalum) and the Japanese natural effect, start with green or blue, then snowball viburnum (Viburnum plicatum) the previous season is gone, along softly highlight with cranberry, pink, or bur- are in the Adoxaceae (formerly classified with all of the current season’s flower gundy. Experiment! in Caprifoliaceae). buds. Even if the winter is mild, a late Vol. 27, No. 3 Hardy Plant Society/Mid-Atlantic Group 3 cold snap, with temperatures dipping temperatures of about 26ºF or less. below the mid-20sºF, can kill actively The 8' deer fence and four dogs deter growing woody stems or damage their Bambi. Vigorous, well established burgeoning buds. Shy blooming might plants overwinter better than the newly also be caused by the gardener who planted. Varieties such as ‘Penny Mac’ tidies up the garden, removing all of tend to give some flowers on newer the bare (but budded) wood in fall or wood and the Endless Summer® brand spring cleanups. Also, the deer love of hydrangea flowers on old and new them and they might chew the canes to wood, especially after they have been the point that the buds are destroyed. established for three or four years. Do Again, no flowers are produced. be patient with varieties such as End- less Summer® and ‘Big Daddy’ as they definitely just get better photo ©Linda Guy ® and better with age. Hydrangea Magical Ruby Red Hydrangea macrophylla Michael's Personal Favorites (Bigleaf Hydrangea) comes in Hydrangea macrophylla—blue to pink white and also in shades from flowers, pH dependent, salt tolerant. rich pink to purples, mauves, ‘Penny Mac’—blue to pink flowers, reli- and blues. The colored forms able, medium-sized flowers, reblooming. Endless Summer®—medium flowers, can be altered by soil pH and extremely reliable, reblooming. aluminum levels in the soil. The ‘Big Daddy’—large flowers, reliable whites mostly turn to greens or bloomer, long lasting. age to soft pinks and greens and ‘Lemon Daddy’—tends to pink, me- photo ©Simple dium flowers, chartreuse foliage. Hydrangea paniculata standards give a can only be changed with floral ‘Nikko Blue’—medium flowers, reliable. freshness to the late summer garden. paint directly sprayed onto the ‘Tokyo Delight’—blue and white lacecap. blossoms. We have many times Hydrangea arborescens—mostly green To encourage these types of embellished fading blooms in the buds to white flowers, aging to green, salt Hydrangea macrophylla to flower garden with floral paint, especially for tolerant. ‘Annabelle’—old favorite, reliable, col- well, you can start by planting hardier garden parties, just as we do with the onizer, excellent for drying. varieties (see sidebar) that withstand fading blooms of giant alliums in late Incrediball®—large upright flowers, ex- our winters. Pruning before mid-July, June or the white flowers ofViburnum cellent for drying. Invincibelle® Spirit—pink flowers, re- and then not again until after flowering macrocephalum, which make for early bloomer. the following season, will ensure that ‘hydrangea-like’ pink or blue flowers Hydrangea quercifolia—excellent in the canes go into the winter as viable, in April and May, well before the mop- shade, great for drying, fall color, exfoliat- budded wood. Planting them out of the heads bloom. Lacecap hydrangeas can ing cinnamon bark. I like the species more way of the cold and dessicating north than most of the selections, widespreading be treated in the same manner to adjust and open habit. and west winds; using antidessicants, color with pH and aluminum levels. ® Hydrangea paniculata—mostly whites such as WILT-PRUF ; covering stems For pink hydrangeas, maintain the fading to green with pink touches, sun in- with Reemay®, burlap, or even sheets pH at 6.0 to 6.2. Raising the pH to tensifies color. in early spring, to protect emerging about 6.5 produces the most pink but ‘Tardiva’—large and open growing, shade tolerant, excellent for drying. buds from late freezes; and guard- avoid raising pH above 6.5 because ‘Limelight’—lime green aging to white, ing against deer with sprays or other iron deficiency can be a problem. Fer- then pink, reliable. repellants can all help to give you a ‘Phantom’—huge flowers, ivory to white tilizers relatively high in phosphorus ® good crop of flowers. Since I live on Quick Fire —earlier bloomer, white ag- (the middle number) help to produce ing to deep pink. the north side of a hill (plants there are stronger pinks. First Editions® Vanilla Strawberry™— less likely to bud out early) and most Blue hydrangeas require a pH huge flowers, white to rose to bright rose. of my garden is protected from the under 6.0, the bluest at 5.2 to 5.5. Best Hydrangea petiolaris—climbing (cling- west and north winds, that leaves me fertilizers include aluminum sulfate to ing) woody vine to 60' in my woodlands, white lacy flowers. with just deer and late spring freezes. raise the level of aluminum and lower ® Hydrangea aspera Villosa Group—tall I use Reemay to cover plants if the the pH. Adding organic matter also shrub to small tree, lavender and white buds have emerged and are grow- lowers the pH. Fertilizers relatively lacecap flowers, best in shade and pro- ing, and we are expecting freezing high in potassium (last number in tected areas. Native to Himalayas. 4 Hardy Plant Society/Mid-Atlantic Group May 2013 fertilizer ratio) and low in phosphorus H. quercifolia (both native to North range from clear whites overall aging are recommended. America) have traditionally been to pinks and burgundies. Overall plant I have naturally occurring acidic white or shades of green, frequently size, summer foliage color, and fall soil and a wood- with pink and color are also variable and worth not- land setting. burgundy ing. I rarely fertil- highlights Both Hydrangea arborescens (cul- ize, but I do use that intensify tivar ‘Annabelle’ is an old time favor- ample compost with the age ite, recently upstaged by the large and and pine straw of the flow- less floppy Incrediball®) and Hydran- as mulch. Com- ers. The new- gea paniculata flower on new wood post helps in est varieties and thus can be pruned in autumn or maintaining soil include pinks spring.