Ask any 4-year-old what color leaves are, and they’ll confidently proclaim, “Green!” And green leaves are just fine, for the most part. We expect gardens to be basically green, from the verdant lawn to the tops of the trees (at least during the growing season). When it comes to plants, that glowing, chlorophyll-derived green implies life and health.
But one can have too much of a good thing. That’s why our landscaping includes plants with leaves that are a soft silver (that sounds much better than “gray”). No, I don’t want an entire yard full of them, but as accent plants, silvery leaves can make quite the impression.
It seems such a waste—we use a tea bag to make a lovely cup of tea, and then toss it into the trash. It just screams to be repurposed—surely there’s some way to get some extra use from that depleted bag! So it’s no big surprise that the internet is suddenly full of lists with titles such as “7 Random Uses for Used Tea Bags.”
We’ve been enjoying some glorious autumn foliage these past few weeks, but there are plenty of plants that remain stubbornly green. In fact, their leaves stay green no matter what the season—that’s why we call them evergreens. With winter just around the corner, I began to wonder—how do evergreens survive our cold winters? Why don’t they lose their leaves?
You probably remember learning about fall color when you were in elementary school. You know that leaves turn colors before they fall, and it had something to do with chlorophyll. But when is the last time you really thought about fall foliage from a botanist’s point of view?
As gardeners, we want to know which plants turn which colors so we can use them effectively in the landscape. Here in Colorado, most of us know that aspens turn yellow golden, Gambel’s (scrub) oaks become a flaming reddish orange, and burning bushes (Euonymusalatus) shine in stunning shades of fluorescent pink, purple, and red. But why exactly do they do that? And how?
“Deck the balls with boughs of holly” might work well in Merry Olde England, or even in the eastern U.S., but it’s not very practical at my house, just north of Colorado Springs, Colorado. We have too much sunshine, the air and soil is too dry, and our soils are too lean and too alkaline. Holly won’t survive winter’s dessicating winds. At least, that’s what I learned when we moved here.
So imagine my surprise a couple of weeks ago when I was out for a walk in a near-by subdivision, and there were two bushes, covered with green leaves and red berries, planted in the strip of soil between the sidewalk and the street. Could it be?
The huge zucchini leaf looked as if it had been dusted with flour. The man holding it was looking at me expectantly, waiting for my diagnosis. I was volunteering at our county’s Master Gardener helpdesk, providing free gardening advice to the general public. Sometimes we get stumped, but this time I immediately knew exactly what the problem was.
“Your zucchini plants have powdery mildew,” I told the man. “It’s pretty common around here, especially this late in the season.”
They’re chewing holes in my big, beautiful chard leaves, leaving tiny dark pellets of digested foliage to mark their conquests. They jump aside as I walk through the knee-high grass in our field. Until I moved to Colorado I had idea how plentiful grasshoppers are (we’re home to over a hundred different species!), or how much frustration they can cause a gardener.