WHICH CALENDAR DO YOU FOLLOW to time your seed-sowing or other garden chores? The one on the wall or desk, or the one provided by nature? I was reminded of this choice in April when a fellow garden blogger remarked with surprise that I had already planted my peas, which I’d mentioned on Twitter or Facebook. “Are the peepers out there already?” she asked, because she plants peas when the peepers peep, observing a practice based on phenological observations—the “what happens when” of nature-watching.
If you mark down observations about nature year to year—what blooms when, what the weather is doing at the time, what birds or other animals and insects appear or depart on certain dates—and compare them, then you are at least informally practicing phenology. Phenology is the study of recurring life-cycle stages among plants and animals, and also of their timing and relationships with weather and climate, according to the USA National Phenology Network, which also calls this system of interactions “nature’s calendar.”
It’s not the actual dates on a calendar, of course—not things like “plant peas at St. Patrick’s Day,” or “sow tomatoes indoors at tax time” that I use as approximate guidelines when writing my monthly chores lists—but factors including daylength, temperature, and rainfall that affect what happens when year to year, and can serve as cues for the gardener. Nature doesn’t read the printed calendar like we do; I’m not sure what the hellebores and snowdrops (top photo) are trying to tell me out back today.
The tricky thing about phenology is that everyone experiences, and interprets, the cues a little differently. The garden blogger who reacted to my pea-planting, Kathy Purdy of Cold Climate Gardening, has written about phenology before, making just that point by comparing the quite different phenology-based to-do lists of several experts.
So tell us: Do you have any nature cues that you follow year to year at your place to guide your gardening rhythms? To look for Eastern tent caterpillars at crabapple bud break, for instance? To plant potatoes when the Amelanchier, or shadbush, blooms? To prune roses at Forsythia flowering time?
I can tell you that the wood frogs mate when the snowdrops are in bloom. No kidding. Like clockwork.
Have you heard the first peepers yet…and have you planted your peas?
phenology for the greater good
PHENOLOGY SERVES HIGHER PURPOSES than providing conventional wisdoms for gardeners, and particularly in this time of climate change, phenological records are proving especially valuable. The USA National Phenology Network is a partnership among public agencies, non-profit organizations, scientists, educators and even citizen scientists—volunteers including gardeners like us. Its Nature’s Notebook project, for instance, welcomes our observations to help in puzzling out the bigger picture.