Horticulture Beyond the Backyard: A Tale of Three Ditches

Many suburban dwellers see drainage ditches as eyesores, nuisances, potential safety hazards, and even indicators of a “second-class” neighborhood. My tale is not only about three ditches in my own neighborhood, but also about my personal transformation from a ditch doubter to a ditch dabbler to a ditch enthusiast.

Before: work in progress on Ditch Three in April 2001, with plenty of reed canary grass (Phalaris arundinacea) still to be removed. The neighbor’s cypress hedge screens the ditch from their view. Occasional boulders edging the street help guide drivers at night. Author’s photographs

Before: work in progress on Ditch Three in April 2001, with plenty of reed canary grass (Phalaris arundinacea) still to be removed. The neighbor’s cypress hedge screens the ditch from their view. Occasional boulders edging the street help guide drivers at night. Author’s photographs

My husband Ib and I live in an older area of North Delta, in suburban Vancouver, British Columbia. Our storm water drainage system is a patchwork of concrete and plastic culverts (pipes), shallow grass-covered ditches (which homeowners have adapted as extensions of their lawns), and a few deeper ditches—the last vestiges of the seasonal streams that once flowed down our slopes.

Our house sits on a lot that is shaped roughly like a quarter-piece of pie. The outer edge of our piece of pie fronts the street, which means that, in relation to our total lot size, we have quite a daunting swath of municipal property to look after—roughly sixty-five meters (215 feet) long and five meters (seventeen feet) wide. With the exception of our driveway and an adjacent parking strip, that swath of land originally featured drainage ditches of the deeper “wild and woolly” sort.

Like most storm water drainage systems in this area, and indeed just about everywhere, ours eventually empties, without benefit of any water treatment, into fish habitat—a stream, river or bay where fish are trying to survive. At the time my tale begins, however, I was only vaguely aware of the significance of all this.

Ditch One: Neighborhood Eyesore

Ditch One is no more—though in the late 1980s, when we paid the municipality to install a culvert and fill the ditch, we thought we were doing a good thing. Ditch One used to stretch up the street from our driveway, in full sunshine—a jungle of vegetation waving high above the neighbors’ tidy lawns. Despite twice-yearly mowings, and Ib’s occasional Herculean efforts with a scythe or shears, the ditch generally looked messy and unkempt by suburban standards. Neighbors continued thanking us for years after we replaced it with culvert and lawn. Now I wonder what biological treasures might have been lurking in that ditch and on its banks.

After: nearly the same view in spring 2003, with plantings beginning to fill in between rocks and woody debris in the upper portion of Ditch Three

After: nearly the same view in spring 2003, with plantings beginning to fill in between rocks and woody debris in the upper portion of Ditch Three

Ditch Two: The Triumph of Ivy

Stretching in partial shade to the other side of our driveway and parking strip, Ditch Two never quite managed to achieve the rank of Neighborhood Eyesore. Grasses did not grow as exuberantly there, nor was it directly facing any neighbor’s front entrance. Furthermore (forgive us, we knew no better!), we planted English ivy (Hedera helix) on the inside of a low retaining wall; over time, it cascaded over the wall, down the ditch bank, across the ditch and up the other side to the road, obliterating everything in its path.

The great expanse of ivy was healthy, tidy, and much admired by neighbors and walkers. But back in 1998, as I gazed down upon it, I could not help feeling that it was too much of one thing. Ib, having patiently awaited the day when the ivy choked out the last weeds, somewhat grudgingly agreed that I could carve out a little streambed at the bottom of the ditch.

I did this (that short phrase does not do justice to the labor involved and the mountains of ivy produced), and then began lining my little “creek” with rocks—rocks that appeared as I yanked out ivy roots, rocks Ib screened from our garden soil, rocks unearthed at nearby construction sites, and rocks commissioned from family and friends. Ib added some cattails at the lowest end of Ivy Creek, just before it disappeared into the culvert, thus creating a miniature wetland and completing my riparian vision . . . or so I briefly thought.

It did not take long before I began imagining that the creek needed a bit of color. I began slashing and yanking away at other bits of ivy, substituting some easy‑care, drought tolerant perennials. Little did I know that these small labors were but a foretaste of things to come.

Beware the killer pavement

On April 9, 1999, about a year after the “daylighting” of our “Ivy Creek,” the Vancouver Sun published an article by University of British Columbia professor Patrick Condon entitled Beware the Killer Pavement. Mr Condon wrote:

. . . curbs are evil, and I say this only partly in jest. Curbs block rainwater falling on streets from going onto the soft adjoining surfaces. Since it can’t be absorbed, it must be piped. Once storm water goes into a pipe, it is almost impossible to get it out again before it is dumped, dirty and torrential, into the nearest stream—destroying fish breeding grounds in the process.

Suddenly, I saw our neighborhood’s old-fashioned curbless streets and remnant ditches in a whole new light, as “fish-friendly” storm water drainage features. Our ditches slow the torrent, thus reducing downstream erosion and allowing pollutants (road runoff, garden chemicals, car-washing soapsuds, garbage, dog droppings) to settle out and/or break down through exposure to sunlight and air. In addition, our ditches are porous, so that some natural recharge of groundwater takes place, which is good for our gardens and for water conservation.

Large-leaved avens (Geum macrophyllum), in the foreground, was the only native plant found in the ditch when work began; double marsh marigold (Caltha palustris ‘Plena’) and common rush (Juncus effusus) work with rocks and woody debris to help slow and purify the runoff water

Large-leaved avens (Geum macrophyllum), in the foreground, was the only native plant found in the ditch when work began; double marsh marigold (Caltha palustris ‘Plena’) and common rush (Juncus effusus) work with rocks and woody debris to help slow and purify the runoff water

Caring for Wildlife

I job-share a cataloging position at Vancouver Public Library, specializing in science and technology materials. Around the same time that I was pondering drainage issues, I cataloged several titles in the Stewardship Series, published by Naturescape British Columbia.

As I skimmed these publications, another light bulb turned on: ditches have great potential as wildlife habitat for small animals, and as wildlife corridors for larger ones. Ditches can provide water (at least seasonally), mud, rock piles, rotting wood, native and nonnative berries and nectars, and shrubby cover for all forms of wildlife.

I ordered a couple of Naturescape publications for myself, mulled them over at length, went out to have a look at our neighbor’s ditch, pondered the books some more, and looked at the ditch again with an idea for improvement.

Ditch Three: A Preemptive Strike

With Ditch One under lawn and Ditch Two landscaped in rocks and ivy, Ditch Three, belonging to our neighbors, rose to assume the rank of Neighborhood Eyesore. It lies immediately upstream from our Ivy Creek. At thirty meters (about one hundred feet) long, its sunny portions overflowed with reed canary grass (Phalaris arundinacea), which was gradually smothering the five large yuccas and one santolina that had been planted some years before. (Reed canary grass is considered by some to be native to coastal areas here, but has definitely extended its range through human activities.)

The grass was, in turn, facing competition from the much-loathed Himalayan blackberries (Rubus discolor), which were in the early stages of takeover, arching and coiling their way up sunny banks, over the grasses and yuccas, and into the cedar hedge (which hid the ditch from our neighbor’s view). In the shadier areas, buttercups (Ranunculus) reigned supreme—huge, succulent, and doing their best to strangle a couple of flag iris, some gladiolus, and an aromatic patch of lemon balm (Melissa) that, like the yuccas, had their origins in the lovely garden behind the hedge.

Reed canary grass, Himalayan blackberries, buttercups—invasive “thugs,” all of them! And yet . . . a habitat of sorts. Like the English ivy, they protected the soil, they held back the runoff (better than a charming stony creek, in fact) and, as I later discovered, they harbored enormous numbers of hardworking earthworms. I was beginning to see beauty even in a tangled, but somewhat functional mess of alien invaders, but I doubted that anyone else in the neighborhood shared my view.

I was distressed by the thought that the ditch might be culverted, whereupon it would probably become a gravelly-weedy parking strip. Eventually, a “killer curb” would be installed, and that would be the end of yet another stretch of natural drainage in North Delta. The ditch desperately needed a preemptive strike—a splash of beautification that would stave off any neighborhood pressure to fill it in at owner or municipal expense.

Early in 2001, with the owner’s blessing, I started to “play” in their ditch—or rather, the municipality’s ditch, since it is really their property. I contacted the town’s engineering office, to make sure they did not have any immediate plans for culverting, and came away with their cautious approval of my “ditchscaping” project. The municipality would be liable if any flooding were to occur, so, quite logically, they cautioned that I must: (a) not interfere with the ditch’s ability to prevent flooding, and (b) not plant anything large on the outer bank of the ditch, in case municipal work crews needed to bring in trimming or scouring equipment in the future.

Rocks and logs arranged to force the water to “pool and drop,” which creates the perfect setting for skunk cabbage (Lysichiton americanum), flowering near top center, and also allows sediments to settle out of the runoff water rather than harm downstream fish habitat

Rocks and logs arranged to force the water to “pool and drop,” which creates the perfect setting for skunk cabbage (Lysichiton americanum), flowering near top center, and also allows sediments to settle out of the runoff water rather than harm downstream fish habitat

Save a Fish and Meet the Neighbors

The idea of gradually transforming Ditch Three into a quasi-native, quasi-ornamental and fully functional “wetland” garden seemed like a worthy but somewhat unrealistic long-term goal. “Bit by bit, over the next ten years,” said I. Little did I reckon on my own compulsiveness, the growing interest of passers-by, and the clever tactics of our relatively new neighbors immediately across the street from the ditch. They were frequently hard at work in their own front yard, transforming it from a derelict weed patch to a showpiece worthy of Pacific Horticulture. If I cleared the buttercups from so much as a square meter of ditch bank, and managed to pop in a single sword fern,, I would hear them shout, “Lookin’ good.”

I was spurred on to greater efforts. Bit by bit, the grass/blackberry/buttercup (GBB) stranglehold started to disappear, replaced by natives such as elderberry (Sambucus racemosa), vine maple (Acer circinatum), salal (Gaultheria shallon), sword fern (Polystichum munitum), and hardhack (Spiraea douglasii), mixed with various quasi-natives (cultivar cousins, naturalized immigrants) and garden perennials.

Early on in my efforts, few walkers stopped to talk; I probably looked too crazy to be approached—especially as I’m not averse to gardening in the rain or in near darkness. As things progressed, however, I made the acquaintance of more and more neighbors and other strollers, joggers, and cyclists, some of whom came by specifically to check up on the improvements. Most just kept me entertained with friendly conversation as I toiled away in the mud.

Improvements? I was not so sure. Here I was, trashing one “ecosystem” and not certain of any measure of success at replacing it with another one. The GBB cabal kept threatening to reclaim its lost territory, and my landscape “compositions” were frequently a marathon of trial and error plant placement. But the new plants all thrived, with no watering other than during their initial planting.

I referred to it all as my “salmon stream restoration,” though I knew full well that no salmon could ever climb the drainage culvert up the steep escarpment to the ditch—and even if they could, like as not they would find no water in summer and early fall. So the fish were a joke . . . until I learned from a neighbor that he had found salmon fry in a larger ditch at the foot of the escarpment while collecting water for his wife’s biology class. I may not have a salmon habitat, but I did have a “nutrient-bearing stream!”

The combination of plant textures and forms offers year-round interest and wildlife habitat in the naturalistic, but far from totally native, landscape of the lower portion of Ditch Three

The combination of plant textures and forms offers year-round interest and wildlife habitat in the naturalistic, but far from totally native, landscape of the lower portion of Ditch Three

In Praise of Yuccas, Stumps and Woody Debris

I was raised to “make do” and “waste not,” so there was no way I was going to get rid of those five established yuccas, even if they were not my idea of “native habitat.” They were healthy, tough, drought tolerant—and probably nearly impossible to dig out, anyway. The yuccas became goalposts on my struggle up the ditch. One by one, I extricated them from their GBB captors. One by one, they became focal points around which to build little chunks of landscaping. They added coherence and a mature look to the evolving chaos.

Similarly, three old Douglas fir stumps provided more good focal points, plus of course their nutrient and habitat value for bugs, plants, and woodpeckers. Following Naturescape BC’s advice, I added more “woody debris,” some of it offered up by neighbors, some from our own garden, some from strangers’ roadside garbage piles, and all of it a great aesthetic and functional addition to the ditchscape.

Compost Chief, Rockhound, and Green Thumb 

For the most part, I worked on my own, enjoying the setting, the physical exertion, and the solitude punctuated by conversations with passers-by. But while I got the public credit, Ib took care of essentials that made the whole enterprise possible. He moved immovable boulders, composted impossibly dense mats of grass, and dug planting holes through hardpan.

He humored me in my ill-fated experiment to transplant some heavy clumps of reed canary grass, which I thought might be tamed sufficiently to form a part of the ditchscape. A couple of months after Ib’s transplanting labors, I decided to remove them. They looked innocent enough in early spring, but by summer, at five feet tall and their roots beginning to ramble, they were obviously incapable of “playing nicely with others.”

And the rocks! Though the ditch banks themselves produced an enormous number of rocks, which I tossed into the creekbed, there was always room for more—especially large ones, for ditch bank stabilization, small‑critter habitat, and aesthetics. Ib collected and ferried countless loads of rocks from vacant lots and building excavations in our family wagon.

In addition, experienced plantsman that he is, he propagated seeds and cuttings in his small greenhouse. Geum, burdock, dryas, lupine, mimulus, and others began to crowd onto the greenhouse table alongside Ib’s various other projects. The only native plant I had identified and liberated from suffocation, along the entire bank of Ditch Three, was a large-leaved avens (Geum macrophyllum), which bloomed enthusiastically all summer long, so I was especially excited about the prospect of more grown from this plant’s seeds. (As it turned out, it also self-seeded profusely.)

The Source

As summer wore on, I slogged upstream toward “The Source,” the two plastic culverts which fed storm water into the ditch at its highest point. Family arrived in time to help clear the grass and blackberries from around The Source and install a grotto. (More rocks please, Ib!) Then in went the shrubs and ground covers and a final yucca donated by neighbors.

At last, including Ivy Creek, our ditchscape stretched from its rocky “spring” at the top, past open, sunny “meadows” of sorts, through a shaded woodland, and finally down to the cattailed “wetland” at the lowest point, before entering the culvert. There was still more work to be done, clearing a last stretch of reed canary grass on the outer bank, and filling in gaps in the vegetation, but things were “lookin’ good,” after just one growing season (and it was largely a clearing season at that). Under winter snow, one could almost imagine that the ditch was indeed a lovely, unspoiled creek.

Late fall along Ditch Three, with the brilliant foliage of smoke bush (Cotinus coggygria) and colorful bark of red-twigged dogwood (Cornus alba ‘Gauchaulti’) and white fruits on native snowberry (Symphoricarpos alba) behind the yucca

Late fall along Ditch Three, with the brilliant foliage of smoke bush (Cotinus coggygria) and colorful bark of red-twigged dogwood (Cornus alba ‘Gauchaulti’) and white fruits on native snowberry (Symphoricarpos alba) behind the yucca

Two Years to Fill In

Compared to the first year, 2002 and 2003 have been a piece of cake! A few days’ labor took care of the remaining grasses—and regular GBB patrols down the ditch, coffee cup in hand, seem to have won the war against those invaders. Empty spaces are gradually filling up with Ib’s greenhouse output, plus natives and perennials from local nurseries and from plant sales at the University of British Columbia Botanical Garden and Vancouver’s VanDusen Botanical Garden.

Now, little more than two years since I began, I can stand back and watch how it all evolves. For the time being, the habitat is still rather open—great for robins, bathing chickadees, peanut-hiding Stellar’s jays, and the occasional rambling raccoon or stump-chucking woodpecker. No sign yet of frogs, salamanders or garter snakes, but I’m hopeful. In place now are all the rock piles, the rotting wood, the mud, and the “pool and drop” structures that force flowing water to slow down, pond, and then overflow and drop to the next level. Meanwhile, all the plants are thriving and filling in—beyond our expectations and with no pampering of any kind—and should soon produce lots of shrubby hiding places and succulent berries for the birds.

The plantings and ditch banks have withstood freezing, thawing, snowmelt, torrents of rain, heat and dry spells, and a veritable Niagara of water main flushing. (Delta Engineering produces this amazing phenomenon by fully opening a fire hydrant and running the water through a chlorine-removing contraption and thence into the ditch, over a period of thirty minutes or so.) Storm water runoff has washed road sand into culverts, and from the culverts into the ditch, where it has formed miniature sandbars here and there. Nothing like Nature to make things look natural!

An End and a Beginning

Thus ends my tale, but I hope it might also be a beginning for other gardeners and nature enthusiasts. There once were dozens and dozens of little salmon streams in the Vancouver area and elsewhere in the Pacific Northwest. Their destruction did not happen overnight; it happened, one culvert at a time, as ever-larger, ever dirtier volumes of water were piped into local watercourses.

Preserving one short stretch of open ditch will not accomplish much. But preserving many ditches, in conjunction with other drainage improvements such as storage ponds and stream daylighting, could make a huge difference. In our immediate neighborhoods, we could enjoy “ditch-based” riparian/wildlife/parkland corridors. And in the larger setting, we could once again take our children to a nearby creek to watch the miracle of wild salmon returning to spawn.


Tips for Ditchscapers

There are just two absolutely critical concepts that ditchscapers must always keep in mind:

(1) The ditch must continue to do its job of preventing flooding of neighboring structures, roads, and gardens.

(2) Every ditch, like every culvert, eventually empties into fish habitat.

All the other principles of ditchscaping flow from the above two basics:

Check with local authorities before starting work. They need to know that you will not interfere with necessary drainage, and you need to know that they will not infill or mow your emerging ditchscape.

• Never obstruct the flow of water, but seek only to slow it down. “Pool and drop””structures made from rocks or small logs are good, if the ditch is deep enough. Cattails and other water plants are also okay, but be careful that they do not become so dense as to impede drainage.

• Never ever use fertilizers, herbicides, pesticides, or gas-powered equipment in a ditchscape.

• Chlorine is highly toxic to fish and amphibians, so never allow tap water to enter ditch water. (In other words, avoid irrigating in a ditch.) Rain barrel water is fine, as is water which has sat for several hours and been stirred to let off chlorine gases. All the more reason to choose native and drought-tolerant plants, which manage amazingly well with no supplemental watering.

• During the initial phases of ditchscaping, there is a great danger of making water conditions worse for downstream fish. Silt kills fish, so do everything you can to minimize downstream silting. For example:

(a) Begin in the dry season by creating a shallow pool (ideally, planted with some cattails or rushes) at the lowest point in the ditch. This will allow any silt you do churn up to settle out, before the water goes on to downstream fish habitat.

(b) Work when water is low or absent.

(c) When there is water in the ditch, do not walk on the ditch bottom unless it is protected by rocks or thick vegetation.

(d) Make ditch bank and ditch bottom stabilization a top priority.

• Native versus non-native plants? Personally, I like the eclectic approach. I suspect it is more likely to appeal to the whole neighborhood than a strictly native approach, plus it is faster and less costly to fill in gaps with divisions of ones own or ones neighbors’ familiar perennials. But avoid “thugs,” the most invasive alien plants, such as Scotch broom (Cytisus scoparius), purple loosestrife (Lythrum salicaria), and English ivy (Hedera helix), whose seeds or berries can easily be spread downstream and elsewhere, squeezing out native vegetation. If you find any natives in your ditch, leave them; they are telling you they like it!

• Do not remove native plants from the wild; purchase them, grow them from seed or cuttings, or rescue them from construction sites. There is no point in creating an artificial natural habitat at the expense of a real natural one.

• There is a lot of good advice out there for creating habitat gardens. Most of it can be adapted for ditches. I relied heavily on the following few sources, simply because they are good, and I had them close at hand.

 

Campbell, Susan. Naturescape British Columbia: Native Plant and Animal Booklet, Georgia Basin. Victoria, BC: Naturescape British Columbia, 1995.

Campbell, Susan and Sylvia Pincott. Naturescape British Columbia: Provincial Guide. Victoria, BC: Naturescape British Columbia, 1995.

Clark, Lewis J. Wildflowers of the Pacific Northwest from Alaska to Northern California. Sidney, BC: Gray’s Publishing, 1976.

Pettinger, April. Native Plants in the Coastal Garden. Vancouver, BC: Whitecap Books, 1996.

Pojar, Jim and Andy MacKinnon. Plants of Coastal British Columbia. Vancouver, BC: Lone Pine, 1994.