It started with this idea that everything would be much more attractive and efficiently laid out if only there was a dedicated space for perennials.
My asparagus was doing well, hanging out in a big sandy berm that used to form a sweeping naturalistic border across one side of the veggie patch. It flowed in, diving the curving diagonal of lawn from the rectilinear order of the 8 original raised beds.
The problem was, my raised beds were marching across the lawn like soldiers. A nice, rectangular little garden shed went in. Sweeping vistas of grass were cut up, dug out, flipped over, fed to worms. The curving gentle asparagus bed was now decidedly out of place, surrounded by so many 90-degree angles. In addition, the natural fall of the yard between the shed and the back raised beds was about 2 ½ feet and was awkward. Half the shed was stuck up on 4×4 stilts. It worked, but it wasn’t elegant.
We sketched and measured and sketched some more. We had a space about 18′ x 10′ to work with, and had to deal with the slope. The solution was half-retaining wall/half-perennial bed. Our final design was simple: a big rectangle built out of 5×5 rough-hewn juniper timbers with three tiered levels, working up to connect the lower and upper levels.
And I’m happy to say, it worked. Here’s how we did it:
Maggie & Jim of Casa de Arboles deliver our Juniper Timbers. They are Alpaca farmers who are the Western WA distributors for Western juniper wood.
We started by using twine to line out where the timbers should go and trenching a level-ish base for the timbers.
The fall of the ground from the back to the front of the shed was enough that we stair-stepped the first course of timbers. The timbers were set on a base of crushed rock.
Some spots were extra mucky and we had to use a little extra rock. Here Nick managed to step out of his shoe after it got suctioned into the mud (by the way, if you want a sexy pair of Muck boots yourself, you can find them under the Resources tab in the Gardening Tools category. I prefer the boots but Nick loves the easy-on, easy-off shoes. In this case, maybe too easy-off, huh?)
We got the first course laid in. Notice that the back is actually 1-level taller than the front due to the fall of the ground and my refusal to dig any more than I needed to with a kid on my back.
I’m not kidding. Every step of the way, little man was strapped to my back.
After we got the first course all level and square, Nick drilled ⅜” holes through the timber and we hammered in 24″ lengths of rebar to anchor the timbers into the ground.
Look at that kid, sleeping while I work. Those suckers aren’t moving now, though, I tell you what.
The next courses of timber were laid Lincoln Log style over the first. Nick used a 1½” spade bit to drill countersinks in the timbers, then attached each course to the one below it with ⅜” x 8″ lag bolts with 1 ½”x ⅜” fender washers. Each countersink was coated with waterproof epoxy because I’m extra aquaphobic about wood.We ended up with three courses at the front (nearest the veggie beds), four at the high-ground half of the back (by the shed) and five at the low-ground half of the back, with the difference being because of that initial stair step.
The dividers between the levels were built of two lengths of timbers. The lower beams were cut 5″ shorter on each end than the upper beams to compensate for the 5″ thickness of the timbers. The two levels were screwed together in the middle and on each end. In this way the upper beams hung flush with the outside of the bed and the lower one recessed inside the bed. We did this so that, when the beds are filled with soil, the roots of the plants will have free range of the whole bed, not just their level, but the visual divide between levels will be clear.
Kidlet was excellent at putting the timbers together. It’s basically like huge Legos, so she was a natural.
One three-day weekend later, our three-tiered bed was done. We finished a bit late, as you can probably tell from the nighttime shot of the bed. Our job for the upcoming weekend is to fill this sucker with soil and compost and get the asparagus crowns and rhubarb replanted.
I couldn’t be more happy. The bed turned out beautifully. It solved the slope problem and will be just lovely filled with perennials for the next 30 years.
If you are thinking of building a long-lasting bed like this, I would encourage you to look at juniper timbers. Based on our research they seem like an excellent alternative to pressure treated lumber. As they weather and age I’ll report back on their actual durability.
Here’s a few more pics of the finished bed from this morning, all dusted in snow. Still need to get this sucker filled with soil. Good thing I have 18 yards of it coming tomorrow.