Taking It to the Bank

July 14th, 2020

   Planting a steep bank is one of gardening’s worst challenges.

This is part of the bank nightmare as I found it in winter.

   When the bank is covered in weeds, pock-marked with rocks the size of riding-mower engines, and obscured by poison ivy, wild grape vines, and wintercreeper vines growing 40 feet up half-dead trees, it’s more nightmare than challenge.

   That’s what I faced in my new Pittsburgh back yard, which for some reason seemed like a doable challenge at buying time a year or so ago.

   Neighbors told me the previous owners seldom ventured outside, and other than a once-a-year leaf-raking, didn’t do any yard maintenance in the eight years they lived there.

   The huge bank across the whole back yard certainly showed it. The bank runs more than 100 feet across and 30 to 40 feet up, with a slope angle of about 45 degrees… enough to easily slip on (which my bruised elbows will verify).

   After a year of brutal labor, I’m getting it under control. I thought I’d share what I’ve done in case others of you have similar banking problems… or just enjoy a good horror story.

   The first job was to clear out eight years’ worth of weeds and jungle growth. I started by pulling and cutting vines out of the trees, then used my electric Alligator Lopper to cut down scrub trees and several smaller dead ones. I weed-whacked, pulled, and dug the lower herbaceous weeds.

Here I am trying to get 40-foot-tall vines out of the trees.

   Despite watching out for poison ivy, I got rashes several times. For one thing, when you have such a mish-mash of long-ignored weeds, it’s easy for young poison-ivy plants to be hiding in the clumps. For another, the allergenic oil in poison ivy can stay active for years even after a poison-ivy vine has died.

   I tackled the jungle for hours at a time over weeks and finally was able to beat everything back nearly to ground zero.

   This created a colossal amount of “biomass.”

   I chopped larger wood into logs that I stacked in a pair of three-foot-high piles toward the top of the bank. The idea is for these to double as “walls” along the downhill side of a path that I cut across the entire top. (I’ll eventually burn the logs in our outdoor fire pit.)

   I piled the branches, vines, and other weeds and ground them all up with my chipper/shredder. The poor machine took such a beating that I had to patch the hopper back together with bolts and a wooden panel.

   I used the chippings as mulch in that path atop the hill – which both saved money on buying mulch and avoided hauling it to a dump. Surprisingly few weed seeds have come out of that mulch, although it’s entirely possible there’s some poison-ivy “juice” in it.

A new fence marks the right boundary of the bank, which I’ve largely cleared by the time of this photo.

   I hired a fence company to install a privacy fence at the top boundary of the right side of the bank (mainly to keep out deer, which is another story), and then I installed a plastic deer fence the rest of the way until it connected with an existing front and side-yard fence (which I’ve since had to replace in yet another brutal-labor story).

   I also had to hire a tree company to remove three large, dead blue spruces.

   Once the playing field was more level (so to speak, since the angle is still 45 degrees), I set to work trying to reclaim the left side.

   I decided to turn this into a low-care wooded hillside by planting a trio of small trees (American dogwood, serviceberry, and redbud) with a line of five blue hollies toward the top. The hollies eventually will become the wall in place of the current log pile.

This side of the bank now has hollies, junipers, and spireas as a three-layer woody groundcover. Stacked logs make a “wall” at the top. A path runs along the other side of the logs.

   I then filled in the middle of the bank with five ‘Grey Owl’ junipers (a “nativar” that hopefully will adapt to what will become dappled light) and finished the bottom with Double Play Pink spireas and catmint. It’ll stay hot and south-facing out of the trees’ reach down there, so I wanted something that can take abuse as well as cover the ground to lessen future weeding and mulching.

   I lugged mulch in five-gallon buckets up that hill after planting, leading to a case of bursitis in my knee that got infected after the ortho doctor drained it. That put me out of action for nearly two weeks last year. But it looks a lot better now! (The bank, not my knee.)

   I left a four-foot-wide channel down the bank next to that area, both as a path and a place for the grandkids to water-slide (my wife’s idea). (Click this link to see a video of the kids in sliding action: Leona.Georgie.water.slide1)

   That divided the bank into a middle section, which I’ve decided to let in a semi-tamed version of its old self.

   Years and years ago, a previous owner must have attempted to landscape the bank. I’ve found evidence of stone terracing (long covered by weeds and decayed leaves) as well as a few scattered survivor plants, including a lone rose, some bishop’s weed, a Siberian iris, and a gold-leafed spirea.

   The earlier owner also planted a boat load of tawny daylilies – those orange-blooming ones that have become thugs in the wild, earning the nickname “ditch lilies.”

   I’m not a fan of them and wouldn’t have planted them, but they’re so entrenched in this middle section of the bank that I decided to cull out the even-weedier competitors and allow the daylilies to make a solid cover. I’ll whittle them down in time and replace them with something better.

   I did remove one section of them already to plant an Oriental spruce (one of my favorite conifers) and a trio of ‘Green Giant’ western arborvitae as screening from the neighbor’s house above.

These salvaged fence sections help screen off the “ditch-lily” section. I’ve planted a garden in front of it with Hinoki cypresses flanking each end.

   To soften the blow of giving in to the thug daylilies, I salvaged two eight-foot sections of the old front-yard wooden fence and used them as “ditch-lily screening” at the base of the middle section of the bank.

   I left a four-foot open space between the sections, where I then built trellising to support a vine. I finished that off by digging a two-foot bed across the front for a perennial garden, which is now planted with black-eyed susans, hardy hibiscus ‘Midnight Marvel,’ golden lilies, and red beebalm.

   The right side of the bank has been the biggest challenge of all.

   There’s a major drainage issue over there that literally turns into raging waterfalls when we get a heavy rain.

The bank during a heavy rain.

   Water comes shooting like a fire hose from the higher ground above and for years has been washing down, over a retaining wall, flooding the back yard, then rushing down steps to the driveway in another raging falls.

   Borough officials had a look and said it’s just “natural runoff” and not the result of any misguided drain-piping or other issues that might fall under code enforcement. I later found out that this whole area is prone to drainage problems because of the many hills, cliffs, and high water tables. I’m far from alone.

   Rather than blowing a ton of money on excavation and piping, I tried digging a trench and filling it with two tons of stone that I lugged up the bank in five-gallon buckets. (No bursitis this time, at least.)

Digging the trench to hopefully channel water down the bank in a stone stream bed.

   I dug a pit at the top of the bank where the fire-hose flow emerges and built a stone retaining wall that hopefully will block the rush. The idea is for the water to fill the stone-filled pit and disperse it up and out over a larger area, including down the trench I dug.

   I’m hoping I’ll at least be able to get rid of the water in a more controlled, spread-out way instead of the focused rush that people apparently lived with here for 50 years.

   Time will tell if I’ve solved the water problem. In the meantime, I turned my attention to the last phase, which is planting the right side of the bank.

   Like everything else, this has been brutal, too. Not only is the soil a very heavy black clay, it’s loaded with rocks. Some of them are flat ones from the earlier terracing attempt, some of them are diggable and about the size of tennis balls, and some are huge and removable only with a pry bar.

I dug a pit to slow the rush (right) and built a bridge to walk across the stone stream bed at the top of the bank.

   I used to garden with shovels and trowels. On this bank, I’ve found myself gardening with pry bars, an ax (to cut out roots from the dead spruce trees), and a mattock.

   The soil is so bad that I have to improve it with compost and mushroom soil before replanting with any “real” plants. So far, I’ve planted part of the bank with six David Austin roses, an upright Hinoki cypress, a Fraser fir, a purple lilac that my wife wanted, and along the new fence, a ‘Black Lace’ elderberry, a Hinoki cypress ‘Gracilis,’ seven blueberries, and a trial forsythia I got from a grower.

   I’ll get to the rest of the bank eventually, but for now, I’ve planted the midsection with vining and/or space-hog crops like pumpkins, gourds, corn, amaranth, and squash. I’m thinking of planting asparagus on part of it next spring.

   The last job was carrying nearly three yards of mulch in five-gallon buckets up that part of the bank to keep weeds from immediately coming back.

The right side of the back bank, planted with roses, corn, and squash-family plants.

   I really don’t want to have to keep putting in a lot of work anywhere on the bank, so I’ve been leaning toward plants that 1.) are likely to survive with little input, and 2.) take up a fair amount of space so they’ll reduce mulching in the future.

   I’d much rather have a single juniper like ‘Grey Owl’ ultimately grow up three feet and out five or six feet to dominate that space than leave openings for weeds or a need to keep mulching.

   Fewer bigger plants work better, I think, than trying to plant a lot of low groundcover plants like the popular vinca or pachysandra, which can quickly get overtaken by weeds if you don’t police them carefully in the early years.

   One other little trick if you’re planting on a bank… make little planting “terraces” at each plant. The idea is for these leveled areas to slow and capture rain water instead of letting it run straight down the slope, which happens if you plant on the original angle.

   I’ve done it both ways, and those terraces around the plants make a big difference in plant survival – especially in the critical first year or two.

   The only other piece of advice I can offer after all of this is that if you’re thinking of buying a place with a weedy, long-ignored bank… don’t. It’s an enormous amount of work overcoming the eyesoreness of a mess that like.

   Otherwise, just stay inside and tape over the windows. That way at least you won’t see it.