Hydrangeas add color and depth to garden

Published on Wed, Jun 26, 2013 by Jody Hackleman

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It should be a colorful summer in my cottage garden this year – the shabby old rose garden is gone and replanted with healthy, freely-flowering hydrangeas. Last fall the search was on for several dwarf versions that could coexist in a tidy setting amongst rhododendrons and Shasta daisies, and I soon discovered and purchased three small easy-care hydrangeas, all promising an abundance of blooms.

They’re new to me, but the brightly colored “Cityline” series of dwarf garden hydrangeas (Hydrangea macrophylla) have been wowing gardeners for several years now. For those of us with cottage gardens, neat and tidy plants that are good performers are irreplaceable. 

To decide amongst lush violets, cerise and magentas with romantic names such as Cityline Paris, Cityline Berlin or Cityline 
Rio was a delightfully difficult task, but ultimately Cityline Venice won me over with a promise of cherry pink blooms flushed with green. Cityline Venice is sure to complement another multicolored hydrangea “Mystical Opal,” which starts out in baby-pink ruffles and gradually fades to an opaline blend of soft pinks, greens and yellows. These two attention-getters are joined in the new planting bed by repeat blooming mop-head hydrangea “Penny Mac.”

Reblooming hydrangeas are indispensable for prolonging color and interest in the autumn garden. Most hydrangeas set flower buds for the new season in late summer, but reblooming hydrangeas like “Penny Mac” set flower buds differently, and instead of blooming only in July on old wood, they set and bloom flowers on new growth all through the summer and into fall. These remontant – or reblooming – mop-head hydrangeas tend to produce more flowers in late summer than typical hydrangeas.

Mop-head hydrangea flowers, unless they are pure white, will be pink or blue (or somewhere in between), depending on the pH of the soil. “Penny Mac” is a good example of a hydrangea that can be customized for your planting scheme. 

If blue flowers are desired, in early spring make the soil more acidic by adding aluminum sulphate. Be sure to follow instructions on the packaging to ensure that you do not burn the plants. Soil can also be acidified with an abundance of organic materials such as conifer needles, sawdust, peat moss, chopped up leaves or coffee grounds. Remember to retest your soil to monitor effects over time.

I’m promoting blue flowers on my classic mop-head “Nikko Blue” and newcomer “Penny Mac,” and since they share enriched acid soil with rhododendrons, all should be happy together.

To add to the garden delight, this year marks the first bloom on my Oak-leaf Hydrangea (Hydrangea quercifolia “Snow Queen”). I’ve had this shrub for four years and although it has grown steadily and produced a bounty of oak-shaped leaves that turn a lovely scarlet red in fall, each summer it has failed to bloom. I’ve longed to experience the graceful white bunches of flowers that initially caught my eye in the garden center.

Over the last winter I did some research and discovered that three or four seasons without blooms is quite normal, as long as the plant has been given adequate (but not too much) water and has been fed a balanced slow-release fertilizer in the spring. 

As recommended, for good measure this spring I gave “Snow Queen” a bonus feeding of compost, blood meal and wood ash. At last, she’s now covered with puffs of snowy white panicles of bloom that I’ve been waiting to see.

Does the cottage garden have room for another hydrangea? Well, yes – there’s a small corner where for years I’ve attempted to establish a “Gertrude Jekyll” rose. This space does not receive the full sun needed for poor Gertrude to thrive, so I have been searching for a small-scale hydrangea to fit this space. Luckily I found “Mini Penny” – a compact pink (or blue) mop head that will grow no larger than three feet high and wide. She’s ideal for containers too, or replicated in a mass planting. Gertrude will be relocated to a sunnier spot to establish her magenta blossoms while Mini Penny gets rich alkaline soil to keep things in the pink.

Established hydrangeas are generally trouble-free performers, leaving the gardener more time to spend on other summertime chores. Since we’re in the Northwest, we might use some of this time to plan a winter garden. July is the perfect month for hoicking out bolted spinach and other heat-intolerant greens, and for preparing the soil for another round of vegetable growth.

A “second season” winter garden should be planted out by early August and might include cool season crops such as radishes, spinach, arugula and Asian greens that can be enjoyed by November. Don’t neglect to plant some carrots, beets, kale, parsley and chives for enjoyment all throughout the winter in our mild climate.

Happy gardening in the summer sunshine!