Urban Forest Retreat

Highly engaged gardeners, people with strong opinions about their gardens, who fully enjoy the time they spend in their gardens, make the most interesting clients. Add to that a friendship that goes back decades, which makes for more even enjoyment when it comes to developing a design. And as if what wasn’t enough, add the particular design challenges posed by a triangular, sloping property with especially difficult soils, and some pre-existing hardscape features that just weren’t meeting the clients’ needs for outdoor living space. In a nutshell, that was the situation we started with in Scott & Jenise’s northeast Seattle garden. Wonderful friends with some interesting puzzles to solve in terms of existing site conditions.

2013 – Phase one – The patio garden

The Starting Point.  The reason the grass was so green: it was wet most of the time.  The concrete was unattractive and really “old school,” poured in patches separated by wood, but functional needs and costs prohibited its complete removal. The patio space was dysfunctional, but how to turn it around?

The design solution was to get rid of the lawn, and create a new, larger patio, building low walls of Montana slate to define and separate the new stone patio from the remaining concrete. No more wet lawn to mow or slog through, and more spaces for the social gatherings that Scott and Jenise enjoy so much.

The Process. The concrete was carefully broken into uniform strips and stored in the upper garden, for future retaining walls.  Fixing the drainage occurred first, by laying down a drain field and underground gravel sump to divert rainwater back into ground-water.  Plywood forms were built for the backside of the mortared rock walls. The corner planter, which separates the old concrete and new stone patio, has tapered walls so that the wood easily slips out after the mortar sets.

The wood was stripped out before the capstone was mortared in place. The black poly pipe was installed earlier, to be used as conduit for half-inch drip irrigation tubing.  Laying conduit is always a good idea whenever hardscape elements are added to the landscape.  Already the new stone walls are in conversation with the dry-stack wall that Scott and Jenise had built before they hired me to create a design for them.

With the ledgestone in place, installation of the Park City Slate was all that remained to do.  The very hard, light colored stone is ideal for this garden because it is highly reflective in low light, and the hardness provides a clean surface over time, and thus makes for great seating, unlike many sandstones.

At this point we concluded work on the garden for that season.  The next step for the patio would be to pick out new furniture and begin to enjoy!

2016 – Phase two – The upper garden

The idea to complete the garden began when a wind storm dropped a Western Hemlock over the fence into the neighboring property.  Scott fixed that, but not before starting a conversation about finishing the upper garden.  The space looked more like a supply yard than a garden, with stacks of urbanite (broken concrete) and leftover Montana Slate Ledgestone, a whole fence worth of salvaged Cedar grape-stake fence panels, piles of sometimes decaying firewood, piles of arborist chips, and salvaged topsoils.  A wheelbarrow ramp path went part-way up the slope, ending in an old set of stone stairs (a remnant of an earlier rockery.)  A Montana Slate staircase, part of the lower retaining wall, ended rather abruptly in a patch of weedy grasses.

My design concern was to utilize all the on-hand resources in the execution of the project, applying the permaculture principle to Produce No Waste.  We chose to repurpose our broken concrete, reuse valuable cedar grape-stake fencing, bury rotting wood in hugelkultur beds to build better soils, and utilize natural stone in key locations for the greatest aesthetic impact.  This strategy presented substantial benefits. Foremost is cost savings, but more importantly this leads to reduced environmental costs.  Fewer truck trips alone helps to reduce carbon dioxide emissions. The design solution was simple in concept: use urbanite retaining walls to build planting beds to improve soils and minimize erosion.  Woven through the beds is a two-fold pathway system that completes the wheelbarrow ramp and a new staircase that connects the two existing staircases.  Challenging to work out in plan, but once designed it was easy to build.  Breaking the concrete into long, narrow strips helped to make the best use of the urbanite and the use of mortar made the walls nearly indestructible.  We used Montana Slate ledgestone as a cap to our urbanite wall, and in the process of building the lower garden walls we observed a fascinating detail about this stone.  We knew it had unique colorations, but it also leaches with rainfall and effectively colors the mortar and concrete beneath.

To improve soils we employed a practice introduced to permaculture by Sepp Holzer in Austria, called Hugelkultur.   On steep slopes Holzer created terraces by excavating trenches, then backfilled with wood and soil to create water retentive mounds on the contour.  Several benefits come from this practice:  1) you can bury organic waste products on-site with positive results,  2) as the wood decomposes it releases plant nutrients,  3) wood acts like a sponge, holding water during droughts and reducing the need for irrigation, and 4) greater carbon sequestration as plantings thrive.

We built our hugels by excavating what topsoil we had, laying out the wood and replacing the soils.  Compost was worked into the soil during the shoveling process, and we finished with Arborist’s Chips as a top mulch.  Dr. Linda Chalkers-Scott, in her book How Plants Work, describes the benefits of arborist chips, including that they are practically free and will eliminate most weeds.  Spread six to twelve-inches in depth, soil biota can be greatly improved and weeds smothered out.  I use the website Chip Drop to have them delivered to my home or job site.  For a modest payment you can support the arborists and the website administrators, and bump up your chances of getting faster delivery.

When the lower patio was completed, the Fire Circle was moved to the upper garden, where Scott and Jenise discovered territorial views that include the Space Needle from the new location.  For the new fire circle we built a mortared seating wall, with gaps between stones that allows firelight to sparkle through, using on-hand ledgestone.  We used crushed concrete, 5/8″ PTS, from Pacific Topsoils for fill to make a fire safe terrace.  It is used as a substitute for the more expensive crushed rock, and using these products helps make recycling economically viable.

The grape-stake fence and arbor creates a separation between the garden and work/storage areas, with only the posts and footings being newly purchased.  With the elimination of stockpiled materials, Scott set about decorating with his collection of unusual tree parts.  As a designer, this is without a doubt the most rewarding sign of success.  My goal is to facilitate the interpretation and implementation of my clients’ vision.  It helps that I’ve known Scott for a long time, but also that I listened to what he and Jenise were telling me.  Good listening is key to a satisfying design.

Before planting the beds were amended with compost, a low-pressure irrigation was laid in place, and finished with a mulch of arborist chips to complete the scene.  Plant selection was based upon just a few criteria:  1) native species to recreate a forest allusion,  2) niche analysis and selection of site appropriate plant species,  3) and services provided such as nitrogen fixation, evergreen screening, food sources for wildlife.  Now it’s just a matter of sitting back and watching the growth.

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