Oftentimes we’re challenged with less-than-ideal landscapes. Have you tried gardening on a hillside? Here’s what we did to stop erosion on a hillside and create an easily-navigable garden.
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When we began Hillside Community Garden in 2011, we weren’t excited about our plot of land: a steep hillside, prone to land-sliding and erosion. It was evident that any topsoil and nutrients had washed away years before.
We wanted to find a terracing solution that not only helped stabilize the hillside, but also helped increase fertility (to make up for all that had washed away). Oh, and the solution should be cheap and low tech, because after all, we’re just a volunteer group operating on a small budget.
Check Logs: Terracing on a Slope
As a permaculture practitioner, I see a hillside and generally think, “Swale! Catch and hold and spread water!” However, in the case of a hillside that is steep and unstable, the act of digging swales could potentially make the hillside more unstable.
A Check-Log Method Summary
Logs and brush are laid across the hillside like a beaver dam and held in place with wooden stakes. New soil is added above the dam and planted with perennial trees, shrubs and herbs whose roots will soak up and slow the rain as it rushes down the hill.
The Method: Nitty-Gritty Details in 8 Steps
#1: Drive in stakes along an elevation contour line.
What is contour?
Imagine you have a dinner plate with water on it. As long as all edges of the plate are relatively level (all on the same elevation contour), the water stays on the plate. But if one edge dips too low (changes elevation), the water runs off.
When you build your terrace, find that elevation contour line to keep the rainwater on the plate (terrace). The best way to find the elevation contour is with a low-tech gadget called an A-frame level. Best news? Anyone can build one (promise!). Go here to read all about an A-frame level and how to build one.
Using the A-frame, drive stakes in along the contour line every 2-6 feet. The steeper the slope, the closer together the stakes should be.
We started out by making our own stakes out of waste wood, but as our supply diminished, we bought 2 x 2 x 36-inch untreated pine stakes at our local home improvement store. If you can’t find untreated stakes with these dimensions (I’ve found them harder to come by in recent years), deck balusters like these can be used instead.
#2: Lay cardboard as a weed barrier behind the stakes. (We covered enough space to make a garden terrace 3 feet wide).
If this will be a managed garden and you’re concerned about weeds, then free cardboard is a great weed blocker. Lay the cardboard like shingles on a roof – start at the bottom, top pieces at the top! Overlap the pieces by several inches on all sides – weeds will find any openings.
#3: Lay logs, limbs and brush uphill of the stakes to act as a dam.
We used logs and limbs that we cleared from the area in preparation for this project. If your check log area is already cleared, a local tree trimming company may be able to supply you with the wood you need.
Logs and limbs 1-4 inches in diameter work best. Logs that are 6-8 inches in diameter will work, too, but first, dig a little trench for them to sit in, to take a little pressure off the stakes.
Pile the logs up so that they’re slightly higher than level, because the terrace will settle over time. Like this:
#4: Plug up the holes.
The logs and limbs are packed with twigs, brush, and leaf litter to act as a filter and hold in soil.
As the leaves begin to fall this season, it’s a perfect time to build a Check Log Terrace!
#5: Add soil uphill of the limbs and brush, on top of the cardboard.
If you used cardboard, the soil will go on top of it. Fill the soil until it’s level with the terrace.
The soil will settle over time, so expect to add a bit more in the future.
#6: Observe the terrace after a couple of hard rains.
How did it hold up? Are there any low spots that need more logs, leaf litter, or soil?
A check logged wood chip path will flank the top side of this fruit tree terrace, which is now planted with pawpaws.
#7: Plant perennials in the new soil.
At our garden, we’re planting fruit trees, berry bushes, and edible/medicinal herbs, but there’s no limit to what you can plant. Just make sure to use perennials, whose roots will be permanent fixtures in the terrace.
Treat your check log terrace like a mini forest. In the forest, you see trees, shrubs, and herbs all living in the same space. Mixing up the types of plants planted on the terrace will provide multiple styles of roots.
For example, fruit tree roots are wide and shallow, while asparagus roots are thick and deep. Each root type will help to hold a different part of the soil in place and will not compete with one another for nutrients.
Berry-producing, nitrogen-fixing shrubs will provide food and fertilizer at the same time!
Note: If you’d like to use these terraces for your annual vegetables, go for it. Check logs will still work for this purpose, they just won’t hold as much water and nutrients.
Be sure to mulch with straw or shredded leaves. Or for a living mulch, plant clover (I like white clover) or an array of low-growing herbs.
#8: Observe over time.
As the terrace settles and decomposes over time, you may notice little spots here and there that need to be plugged up, or a stake that needs replaced.
In general though, this little ecosystem you’ve built will do a good job of stabilizing itself without a whole lot of work on your part.
Would you like to learn more about using the contour of your land to improve the biodiversity of your garden, reduce maintenance, and increase yield?
You’ll find loads of information just like this in my book, The Suburban Micro-Farm.
6 Benefits of Check Log Terraces
#1: Aerate Soil
As water rushes down a hillside, over time it compacts the soil like a well-used sled-riding hill. In order to have a successful hillside garden, this soil must be loosened and aerated. Remember though, digging or tilling can de-stabilize a steep hillside, so we’ll save those techniques for flatter ground.
On the other hand, check log terraces are highly aerated, with air exchangeable through the logs and into the new soil behind it. This air exchange in the new soil improves even the old compacted soil below it. Keep reading to find out how!
#2: Catch Nutrients
Rainwater typically rushes down a hillside, trickles into streams and rivers, and eventually makes its way out to sea. Along this route, nutrients are washed away, never to be available again in the soil. Since there is only a finite amount of nutrients left in the soil, we want to retain as much of them as we can.
Check logs are like nets, catching those essential nutrients before they rush away in the rain.
#3: Improve Plant Life
Before we built terraces, we tried planting in the existing soil, but the plants looked sad and droopy and had yellow leaves. This was an indication of collapsed soil – whereby the air had been pressed out as it was compacted by sheets of rain over time. These symptoms also indicate a lack of fertility.
With the check logs, plants thrive in the loose, aerated soil, rich in nutrients.
Additionally, plants go through growth and die-back stages, feeding the soil with dead roots and dropped leaves.
#4: Increase Organic Matter
Rich, aerated soil attracts worms and other beneficial soil organisms. As they go about their daily business, they eat, poop, pro-create, and die. They wiggle around in and out of the new and old soil, forming little tunnels everywhere they go.
These tunnels are lined with a sticky exudate that they excrete, which helps hold the loose soil together so it doesn’t wash away. The tunnels allow air, water, and nutrients to penetrate deeper into the soil, preventing even more runoff.
Their poop adds to the nutrient density of the soil, as do their own bodies as they die and decompose (both are organic matter), providing more reasons for the plants to be happy.
#5: Attract Beneficial Fungi
Fungi are an indication of healthy, mature soil, and show up fairly quickly in check log terraces because of the decomposing logs. Fungi that we see above ground are connected to one another below the soil surface through fungal networks. These fungal networks form beneficial relationships with the roots of the plants, and catch and hold both soil and nutrients.
#6: Build an Ecosystem with very little work
Ultimately, a check log terrace on a slope will become its own self-sustaining ecological system, drastically improving the stability of the hillside and contributing to the regeneration of an eroded landscape.
A check log terrace is so simple that it’s worth a try on your hillside today. Even better: if you change your mind, it’s just as cheap and easy to deconstruct 🙂
What do you think? Will a Check Log Terrace improve your hillside?