Last Thursday, our sunken garden rock wall construction project began, with the goal of converting a rather boring 130′, dry stacked rock wall, built in 2003, into a more imaginative, botanically diverse rock garden space. As mentioned in an earlier blog, we hired former JLBG staffer, Jerermy Schmidt, now of Hortco, to design and manage the project, with supplemental labor from the PDN/JLBG staff.
The project began with a truck load of boulders that arrived, all selected by Jeremy.
Then, the smaller rocks, in the form of Permatill, arrived on-site. Permatill is a NC mined slate, which is heated in a seriously hot oven, creating a porous gravel.
Below is the site, after the dry stacked rocks were removed and stacked nearby for reuse.
The next item of business was to dig back into the bank to create from more depth for the new wall, and to create closeup, plant viewing cut ins. This meant doing battle with the roots from the giant row of Metasequoia ‘Ogon’, which tower overhead. With help from a rented backhow, we wound up removing at least 1/3 of the tree roots. To be able to do this without killing the trees, the soil must remain fully hydrated, and we must make sure no other damage to the trees occur. Most of the tree roots were in the top 1′ of the soil, although some larger roots had made there way 4-5′ down to the water garden below, disrupting the adjacent paver walk. As they say on tv, do not try this at home.
After two days of root removal and excavation, Jeremy was ready to begin stacking the new rock wall, which would combine the original stacked flat stones with the newly purchased boulders. Below is the beginning.
The large boulders weigh between one and nearly two tons, so a backhoe is needed to set them in place.
Here is the first section, beginning to rise from the ground. Surround the rocks is a soil mix of 25% compost, 25% our native sandy loam, and 50% Permatill (a popped slate, mined in NC).
After one week, section one is nearly complete. Our facilites team of Nathan and Jason are providing most of the labor, while the garden team jumps in, when extra hands are needed. We’ve had several of our volunteers and other interested customers, stop by to watch, ask questions, and some even wanted to help stack rocks for some hands on experience. We want everything we do to be a learning experience, so others can understand the process, and perhaps feel confident to tackle their own project.
We have wanted to tackle this area for over a decade, but it became obvious that Plant Delights would not be able to fund the construction, due to two recent back to back poor seasons of plant sales. In order to make this happen, private outside funding was secured, which allowed us to proceed, just in time for the June 2027 visit from the North American Rock Garden Society, who will be holding their annual meeting here next year. We expect the rock construction part of the project to be nearly complete by the end of next week, October 16. I’m already itching to start planting.
