Traveling shows a gardener unfamiliar plants – or new ways to use familiar ones. My band of travelers, visiting gardens around London last month, saw many new plants and often commented, “Why can't we grow that?”
Sometimes we can grow that, but we don't because of tradition, style preferences or ever-changing trends. Sometimes the answer is that climate rules. England has several weather and soil conditions that differ from Western New York. As my friend Mrs. Howell, who has visited gardens in England, put it: “England is an island. So more sand in the soil, more mist, more seacoast.”
Let's consider some of the plants we observed or lusted after in England. Perhaps some horticultural understanding will follow.
The lime tree
One scene at the Chelsea Flower Show resembled a contagion-theme movie. All along the aisle of small “artisan gardens” everyone began sneezing. Ahchoo sounds dominated the conversational buzz, punctuated by polite Brits saying, “Oh, pardon me ... begging your pardon!” over and over again. I asked people what might be the allergen, and many pointed skyward.
“The lime trees; it's always the lime trees!” they said.
Further inquiries did not help, even in a flower-gawking crowd. Definitely it wasn't a tropical, citrus-producing true lime, and 40 feet up the leaves looked to me like honey locusts.
Mystery solved: “Lime” is derived from the original “Line tree,” which is a Linden tree. In that scene the overhead trees were Tilia cordata (Littleleaf Linden or Small-leaved lime) but Tilia platyphylos (Large-leaved Linden) is also native and commonly used in Europe. Basswood is another common name. We have an American Basswood, but in America the Littleleaf Linden has gained popularity as a successful urban tree for its tolerance of heat and compact soil, fast growth and dense, rounded crown.
Gold dust plant
After traveling I was prepared to introduce Aucuba japonica into local landscapes, as I have seen this gold-spotted shrub used in several parts of Europe. It's also called Spotted Laurel, Japanese Laurel and Japanese Aucuba. Cool shrub. Neat leaf pattern. We use them as houseplants – and it's probably better left to that use. Its hardiness is probably USDA Zone 7, and even if we establish it in a sheltered spot, do we need one more shrub that's not very hardy and native to Japan?
Golden chain tree
In London in May this tree, Laburnum x watereri, became a familiar and impressive sight – dripping with yellow racemes. We can and do use it in America, but it requires specific conditions, neither colder nor warmer than USDA Zones 5 to 7. In the WNY region, it should be somewhat protected from severe winter weather, performing best in a courtyard or building-sheltered site. It blooms in spring, which helps to differentiate it from the similar-sounding Golden Rain Tree (Koelreuteria paniculata), a bright yellow-flowering presence in summer. Great trees in the right location.
I've yearned for a British garden speckled with foxgloves ever since I first saw a flower garden picture book. My Canadian Grandpa Harper grew foxgloves in his border, where I was taught to dead-head, to appreciate bumblebees and ordered to keep the dog from running through the garden. So why do these plants tend to be short-lived? Foxglove, aka Digitalis (from which the heart medication is derived), has a taproot, similar to that of lupines and delphiniums, which requires deep and penetrable soil – the opposite of typical WNY clay. Even if we provide a raised bed with slightly acidic soil, foxgloves may not proliferate for us as they do elsewhere because of our mulching habits: English gardeners do not typically mulch heavily but instead cultivate (hoe) the soil surface lightly. They watch for seedlings. The foxglove seedlings either can't take root in our mulched surfaces or we dump more mulch on their little heads in early spring. Foxgloves, lupines and delphiniums are the poster children for “Right Plant/Right Place.”
Why their roses seem better
Although we have many public and private gardens with extraordinary roses, when one thinks of roses, one thinks of England: roses climbing over thatched roofs, arching over trellises and beds and beds of them stretching far and wide. They appear free of blackspot and mildew, and the smell of pesticides does not linger in the air.
In this case it's all about England's temperate maritime climate. While the latitude of London would suggest winters as cold as ours, the North Atlantic current ensures milder temperatures with hardiness zones equivalent to our Zones 7 or higher. Roses love lots of water and England's skies are generous with rainfall. Further, most fungus diseases thrive during extended periods of high humidity, and are discouraged by breezes and intermittent rainfall interrupted by dry spells. The American rose grower must work harder at creating the right conditions, watering early in the day and carefully, and selecting disease-resistant and appropriately hardy roses. They just don't perform as easily in America.
Gardeners love the exotic
As in America, ecologists and environmentalists educate about the importance of using native plants, assisting pollinators and avoiding invasive plants. In this regard, our culture's similarities are greater than our differences. Public and private British gardens were filled with exotic plants from all over the world. The Himalayan Blue Poppy (Meconopsis) and Prickly Pear Cactus (Opuntia from the Americas) were featured in the flower show. A sea of Camassia at Wisley came from the American Southwest. Hostas – from Japan, Korea and China – are as popular in England as they are in America. The most intense plant people, in England as in America, are often collectors who try to push the limits of what they can grow.
Whether we look at somebody else's garden in Buffalo or Hamburg, or we travel across the ocean to study plants, there is something to learn. Sometimes the lesson is as basic as adding compost to the soil, or the reminder that site and climate rule gardening success. Often we discover plants we want, or design ideas to take home. Always, garden travels open our horticultural minds ever wider.
Sally Cunningham is a garden writer, lecturer and consultant.