By Steven V. Philips –
A “rain garden,” he said? He must mean some mystic sub-tropic thing. Maybe not a Costa Rican “rain forest” but something similar. And up here in North America, without real rain forests, it’s really worth hanging on to as much water as you can, so what’s a rain garden?
O.K. So I’m dozing a bit, listening to a certified arborist and high-degree horticulturalist talk about “green gardening,” and dreaming about the reality of my own garden, when I hear him say rain garden again and something about the practicality of capturing runoff from the roof and other hard surfaces. Free water? Suddenly I’m interested. Oh, yes, I’m fully alert and listening; now it’s your turn.
On your back forty (though you know what I think of all that grass foolishness going on), think about installing dips or gentle slopes in the terrain and fill them with, wet-loving plant specimens. Under the soil should be a bed of gravel to filter the water as it percolates through. Then the water from a downpour will migrate to these depressions (ha!, a rain garden!) and sink in, rather than turning your bedded flowers into pre-compost mud baths. But, No buggie worries. In the summer you won’t have a mosquito problem because there’s no standing water. The concept of a rain garden is to turn storm-water runoff into ground water. Actually, underground water. A rain garden captures water (free water) to keep your lawn irrigated and the water table good. Very environmental.
Another rain garden option – you could separate your lawn from your planting beds with a sweeping dip, called a swale, (rain garden!) to do the same thing. And, if you are a very good person with your totally mulched gardens, use “valleys” (rain gardens!) to retain rainfall.
On to your bullet and water-proof concrete driveway. Run a parallel swale (rain garden!) so the drive run-off goes down into the ground rather than down into the storm drain. Or better yet, use porous pavers over six inches of compacted gravel (more where you have frost..).
And so garden students, in essence, you can be dippy and drippy without suffering social ostracism.
Roof water and no gutters? Under the drip line of your roof run a gravel bed, four inches thick, so the rain ends up draining into the ground and not running off to join the circus. In the South, with slab foundations, this works as described. In the North use waterproof liner, or French drains (hold the Fries), under the gravel to drain the water away from your basement and off to a what? A rain garden! Pay attention or I’ll be lowering your grade..
New as it sounds to you hybrid-driving techies, you could also attach an old fashioned cistern to your gutter downspout. These days special plastic tanks can be hidden under a deck, buried in the yard or just set next to your mother-in-law’s window to let the glugging water drive her nutso. They collect free water from your roof rather than paying the water company.
You could then submerge a pump in the cistern, hook it up to your drip irrigation system and deliver water all over your estate. Or the overflow can be routed to a what? A RAIN GARDEN! Is nobody listening here?
Though it’s a lot of long words for some of you to remember, look at the American Rainwater Catchment Systems Association (ARSCA) Web site. These experts know how you can retain water better than a pregnant woman.
• Look! A 2,000 square foot single-story house roof can collect maybe
1,200 gallons in a one-inch rain shower so it’s worth it to retain that
“abundant dew” on-site rather than let it migrate down the river.
• Internet search: Go to ARCSA.org They have great stuff you never
heard of! Really.
• Gutter into a rain barrel or into a cistern. With either system, screen
that flow of water to keep crud out of your storage vessels.
• Repeat. You can easily make a rain barrel out of a trash can and
there’s nothing like that free, chorine-free H2O!
So unless you’ve drowned by now, you know that it’s silly to waste any (it’s free!) water that hits your roof, yard or mother-in-law. Cultivate a rain garden.