Unless you live where it seriously snows, you probably just think how pretty our gardens look under their winter blankets. And they do look lovely. But underneath Saturday's 6.7 inches of fresh snow is four months of nasty accumulation.
Picture storm after storm dumping ice and snow on your Japanese maples, willows, pines, the arborvitae hedge, the lollipop lilac and the yew globes. At some point, all but the big trees are buried. A lot of the snow that's on the ground has been shoved there by snowplows throughout the winter. On both sides of the driveway the snowbanks are manmade, shaped by shovels and snow blowers.
Last year the garden — front and back, north and south aspects — still had such significant snow cover on March 29th, that we shot a bunch of photos to memorialize the last residue of our record snowfall: 101.4 inches! We're already at 66.5 inches of snow this season, so I may be looking at a similar scene in another month.
Long before Spring, the snow hardens into dirty mounds; they extend far out into the street which slowly narrows over the course of the winter. When the snow finally melts, the gardens that slope down to the curb look like a lunar landscape. The last of the oak and maple leaves — the ones that never got raked up in the fall — are flattened down by the weight of the snow into a mat. On top of it are flakes of yellow paint where the plows scrapped the curb, empty cigarette packs and other detritus. But worst of all is the salty grit thrown up after every melt/freeze cycle.
Looking at this brown carpet last Spring, I wasn't sure the small spring bulbs would even be able to push through such a crusty mat. And if they could, then they'd be resting on all that salted surface. As strange as it sounds, I decided to literally roll up the top layer of leaves and debris and discard it. I got the idea because it started doing that on its own as I was trying to do a little early cleanup.
Because we don't have sidewalks in my neighborhood, I've always been aware that the front sixteen feet of our property belongs to the city. Knowing it might get dug up for utility work or street widening, I resolved to plant nothing fancy or temperamental there. There are assorted bulbs (Crocus tommasinianus, Muscari, Narcissus poeticus), Hostas of every size and sort, Japanese painted ferns, cranesbill geraniums (Geranium macrrorhizum), Lady's mantle (Alchemilla molis), early and late daylilies in shades of yellow and peach (Hemerocallis), and a white rugosa rose.
As for trees, an old Bur Oak — my pride and joy — marks the corner where our driveway meets the street. At some point in its long life, this tree had its bark sliced off on two different sides near the base but still it survives. I'm sure that when the silver and sugar maple trees were planted 50 years ago, when our house was built, road salt was not an issue. Purdue's extension booklet on road salt and plants, suggests keeping sensitive plants at least 30 feet from the road, especially if it has a high traffic volume. Most of the trees just make that cutoff.
When I planted my curbside perennial gardens, I gave some consideration to road construction but none to road salt. Though we've tried to use only sand and ashes on our driveway, some years salt is a must. Locally, the city follows a low-salt diet but there are plenty of times when it's used on our streets. In both instances, that salt winds up on garden beds.
In hindsight, I've discovered most of my perennials are tough; they've survived years of winter salting. The same goes for the trees. According to the University of Wisconsin Extension booklet, "Salt Injury to Landscape Plants," most of our trees closest to the street have a moderate to high degree of salt tolerance. (Purdue also has a long list of the tolerance of landscape plants in their publication).
If I was just beginning to landscape my streetside gardens, I'd use these publications as a guide — not only for tree and shrub choices but for ways of minimizing the effects of salt. One UW suggestion is to create a berm to keep salty water from moving into root zones. Most of my streetside garden is planted on a slope which has the same effect naturally.
But now that I've been reading up on the subject, I'm considering a different approach when the end of March comes around. This time I'll flush the high-saline areas with water to move salt out of the plant's root zone, as both publications suggest. The end result should be less salt and a more healthy garden and leaves that can be left in place to decompose.
