Planting for climate change
Whether your ornamental garden is an established one or you are contemplating starting a new one, the issue of climate change should be part of the plan. Severe weather swings — extreme cold or heat, abnormal precipitation (the long-range prediction for this summer is warmer and drier) and perhaps even all in one season can take a toll on many plants. While it looks as if we can expect even more of the unexpected in weather, there are things a gardener can do.
An especially cold winter, like the one we recently went through, can be hard on shrubs because their structure is exposed to the elements. Choosing those that are hardy for a variety of conditions — both cold and heat — can make a difference. My garden inventory of the past winter’s cold damage uncovered a few losses, but even more encouraging were the survivors which far outnumbered the losers.
I wasn’t the only one who lost a rose or two last winter. My David Austin "Abraham Darby," a survivor for nearly 20 years, didn’t make it this time. Sigh. I sure will miss that guy. And although I’ve heard of gardeners here who grow hybrid tea roses as if they are annuals, I am reluctant to invest in a rose if I cannot depend upon it, especially now that our weather seems more unruly than ever.
That’s where my heirloom “dog” or Jacobean rose shines. This two-story-tall rose didn’t show any damage at all. What a trooper. No wonder this old variety has been around for centuries and in my own garden for decades. It only blooms once and for a short period in mid-summer, but when it does it is spectacular. Also my landscape roses came through the maelstrom in fine form. Just like that heirloom rose, heat, even humidity and things like black spot don’t seem to phase them. This spring my landscape roses got a quick trim to shape them up, a dose of fish emulsion and they are good to go.
The winter took two buddleias also. I and the butterflies will miss those showy blooms come July. But if butterflies are a “must” in your garden scheme, then maybe it is worth taking a chance on a buddleia just for its color and the incredible numbers of butterflies it can attract. However these showy and fast-growing shrubby plants can be tricky here. Care should be taken to avoid trimming them back in the fall because their hollow stems can hold water which will freeze and…well you get the picture. Apply a thick mulch around their base in the late fall. But even then, the plant might not survive, especially in severe winters like the one past.
Of several hydrangeas, my bigleaf varieties showed the most damage. But because mine are the newer varieties that bloom on both old and new wood, they’ll be just fine. Even so, there was a pile of deadwood to trim back. If yours are in the same boat, go ahead and cut those dry stems back, if you haven’t already. The new growth at the base will soon fill in. An application of a fertilizer for acid-loving plants should be applied now. The hardy hydrangeas, like "Pinky Winky" and the new compact "Bobo," plus the smoothleaf hydrangeas, "Invincible Spirit" and "Incrediball" with enormous white balls of tiny blooms all came through the winter with no damage whatsoever. Summer heat is no problem for them either. Just something to consider when selecting hydrangeas.
The lemony-chartreuse spriea, "Glow Girl" and the burgundy-tipped "Artist" made it in fine form also. I like to keep these colorful shrubs trimmed low and round to offer not only a brilliant color contrast in the perennial bed, but a sculptural one as well. Another springtime champ has been the Double Take quinces, "Scarlet Storm," "Pink Storm" and "Orange Storm"’ These thornless quinces are compact with incredible double blooms that hummingbirds cannot resist.
Another tough shrub has been the Rose of Sharon. No damage whatsoever there, and come August these old-fashioned shrubs will be jam-packed with tropical-looking blooms. I especially love the cool blue of the double-bloomed "Blue Chiffon" as well as the saucy pale pink double blooms and luscious blue-green and cream variegated foliage of "Sugar Tip." For deep dark foliage all season, look to the dependable blooming shrub Ninebark, especially the "Tiny Wine," a diminutive3 to 4-foot variety that is perfect for the small yard. Consult the Proven Winners ColorChoice shrub selection for these and other hardy choices.
The "Dream Catcher" Kolkwitzia amabilis has been a fountain of delicate golden-green dotted with tiny pale pink blooms lighting up the shade bed this spring. Come fall it will again take center stage with a golden-orange glow. It is one of a few shrubs that thrive in the dappled shade of our back yard. When it comes to shrubs, I especially like the flowering ones or those with colorful foliage that help provide the “bones’ of the perennial displays while adding interest all summer.
Making another grand appearance this summer is my perennial hops vine, "Summer Shandy." This bright, golden-yellow green vine has a more refined growth habit than most are accustomed to with hops vines. Other winners in the “winter sweeps” were the hostas — all of which did great and are coming back better than ever. "Empress Wu" will be sure to wow everyone with her gargantuan foliage as will the traffic-stopping "Autumn Frost," which always elicits comments to garden visitors. Clematis, peonies, spring flowering bulbs, sedums along with a host of other perennials including some natives like trillium and Jack in the pulpit, show no signs of slowing down now.
Knowing what conditions a particular shrub or perennial prefers, and tailoring the planting location to those needs also can help combat the wild weather swings of climate change. My Heucheras made it just fine — the first time in years that I have been able to successfully overwinter these colorful perennials. This time I followed the advice of those experienced folks at Terra Nova Nurseries, and planted the selections on a slope that offered good drainage. I also gave them a light mulch of seaweed for the winter. It did the trick. A layer of mulch helps to moderate temperatures around the plant. So far the only perennial I am missing is the Brunnera, but I am sure that as the season unfolds I expect to discover that there will be other plants did not make it through.
As I assess the damage and count the winners and losers, I find the vacant places left to be great opportunities to go plant shopping. I will however, carefully consider whether or not I want to replace those plants that gave into the winter’s cold with the same varieties. Some I will, others not. Selection first, and then proper planting and appropriate care, including a winter mulch in some cases, will go a long way to ensuring their survival season after season.
Lynette L. Walther is the recipient of the Garden Writers Association’s Silver Award of Achievement, and she gardens in Camden. Got questions, or comments? Visit her blog, and join in the conversation at: gardeningonthego.wordpress.com or ”friend” her on Facebook to see what’s new in the garden day-by-day.