My back yard is now gravel-free and a whole lot flatter, thanks to a Saturday morning spent relearning how to run a backhoe and front-end loader, which I rented around the corner on Merrimon Avenue. It had been a decade or more since I last operated the mantislike backhoe, and it took awhile to smooth herky-jerky hydraulic motion into some semblance of controlled digging. But I got the job done, including some things that would have meant many hours of extra effort with only a shovel and pick (see “To the Victor, the Soils?” April 19 Xpress).
There were several huge chunks of concrete buried at odd angles, relics of a former sidewalk entombed by some previous owner’s efforts at terraforming this alien urban landscape. Digging them out of the heavy clay soil by hand was happily avoided, and between double-digging my incipient beds and filling in behind the now-straightened retaining wall, there’s still plenty of shovel work to keep me busy. (That too was the work of hydraulic power, accomplished with a pair of 12-ton jacks planted at an angle to the sagging structure. All hail hydraulicism!)
While I was at it, I dug a trench and buried a pile of lumber scraps left over from house projects (not pressure-treated wood) together with a rotting log and some sizable branches that had dropped over the winter. As Masanobu Fukuoka, author of The One-Straw Revolution, discovered through years of experimentation, nothing builds soil faster than rotting wood.
While carrying on with the bed preparation,I’ve had plenty of time to study the trees surrounding my new garden. Now fully leafed, the oaks, maples and pines are providing full shade to all but a small patch of the yard. None of the trees is on my lot, though a few seem to be right on my southern property line.
I have the right to lop off branches overhanging my property, of course, and legalism aside, I will negotiate any outright removal of trees along the lot line, but I will be judicious.
It takes a lot of tree trimming to gain a useful amount of sunlight. Most flowering plants and all fruit-bearing vegetable species need five to six hours of full sun to prosper. At present the sunniest part of my yard gets full sun just before noon and falls into full shade less than three hours later. Late in the day, the sun sneaks around the western end of my house and delivers another hourlong dose before setting.
The shadow of a single leafy limb crosses 40 feet of my space over a four-hour period at midday, so trimming it will garner each plant in that stretch only a dozen extra minutes of radiation. To gain five hours of direct sun in that fully shaded space would thus require lopping 25 similar limbs from east to west, and that doesn’t account for the changing angle of old Sol as the Earth circles through the season.
From the time this story goes to press, the sun’s ecliptic will move farther north for another three weeks. Three weeks after the solstice, its track will be about where it is today. In practical terms, this means that if I can extend my optimum sun by an hour and plant short-season tomato seedlings (say a 60-day variety) that are one-month old on June 1, I have a reasonable chance of enjoying ripe fruit by mid-July.
But for longer-season varieties I am apt to be flat out of luck, because as the sun dips lower in August, the shading limbs will be well over the line into my neighbor’s yard. If those plants do bloom and set fruit they’ll be slow to ripen, though I could get a very late crop if the frost holds off until well after the trees drop their leaves.
What’s true for tomatoes holds for all the other fruiting veggies as well. Eggplant, peppers, squash, beans and corn all need long hours of direct sun to amount to anything — and then there are the flowers. Most annual flowers, the showy ones that really brighten a summer garden, are sun worshippers.
There’s a reasonable chance that I can gain an hour of sun in some parts of my yard with the aid of an extension ladder and a chain saw. But unless a major storm whacks my neighbor’s trees, there’s no chance whatsoever that I’ll be able to grow sun-lovers in most parts of my garden. What to do? Pray for a tornado?
For starters, I’ve planted some impatiens and will put in more soon. Among the most shade-tolerant of flowers, impatiens are available in a growing range of colors and patterns. New Guinea impatiens are particularly showy and, like their commoner cousins, will bloom until the frost. Begonias are another expanding family that offers up profuse blooms in low-light conditions. Hostas sport lovely foliage, either solid green or variegated, and with just a little sunlight will send up spikes of lavender or white flowers.
Other semishade-blooming perennials include thimbleweed (Anemone virginiana), goatsbeard (Anuncus dioicus), astilbe, goldenstar (Chrysogonum virginianum), foxglove, Japanese meadowsweet (Filipendula purpurea), queen-of-the-prairie (Filipendula rubra), queen-of-the-meadow (Filipendula ulmaria), various lilies and day lilies, fire pink, monkshood species, turtlehead, pearly everlasting and the gentians. “Semi” is the operative word here, and while all of these flowers will survive deeper shade, blooms are more abundant in dappled light.
Vegetable crops for shady gardens include most of the greens, but even with those, growth will vary with sunshine and many will tend to languish until the leaves drop in October — while bugs will happily feast on whatever foliage does manage to grow.
The whole arena of day length and the ecliptic provides what for me is one of the great enticements of gardening. An attentive gardener is intimately linked to planetary motion, to the dictates of the Earth’s angular axis of rotation and the varying intensity of solar radiation through the days and through the season. To me, it seems impossible to garden and not experience our sweep through space as well as the hydrologic cycle that engenders weather. At the same time, one comes to intimately appreciate the metabolic process of photosynthesis involving the uptake of nutrients and manufacture of carbohydrates.
It’s all too easy to take sunlight for granted — indeed, some optimists among us foresee the easy option of a solar-powered future free of the pollution and poisonous leavings of our current fossil-fuel economy. But a gardener — even this one, who happily lived in a photovoltaic home for two decades — knows better. Available sunlight is not infinite. And whether it’s the neighbor’s trees or my solar panels, sunlight captured for one purpose is unavailable for another.
According to Jared Diamond, writing in Collapse: How Societies Choose to Fail or Succeed (Viking Books, 2005), the first calculation of the limits of sunlight was done in 1986. At that time, “Humans then already used (e.g. for crops, tree plantations, and golf courses) or diverted or wasted (e.g. light falling on concrete roads and buildings) about half of the Earth’s photosynthetic capacity. Given the rate of increase of human population, and especially of population impact, since 1986, we are projected to be utilizing most of the world’s terrestrial photosynthetic capacity by the middle of this century.”
Short version: Sunlight will be in short supply; there are simply too damn many of us.
Big thoughts to ponder while double-digging this spring.