Notes from Windward: #69


Terracing the Main Garden

Putting to work the concept of reuse

Oana writes:

     Right now the weather is transitioning between the late snow and the early rains. Whenever there's a streak of sunshine we're working on terracing the main garden.

Since it's a lot of work, why are we bothering?

     One of the main problems we had last fall was water retention. I would water the corn, and most of the water would dribble downhill as soon as the straw covering the base of the corn plant saturated. The soil here becomes solid from mid-June to October, and is almost impermeable. Water runs down the hill soon as it gets a a chance. When growing crops, especially water-intensive crops such as corn, that's not a desirable feature.

spring's not quite here yet; the morning after installing the retaining wall

     However, there are a couple things that can be done to remedy this. One is to improve the soil quality by digging in plenty of compost. Another is to make sure that the water cannot run downhill except through the soil. This means cutting into the hill and building retaining walls so that three terraces are formed.

     We've already added some compost to the soil, and as time goes on I'm sure we'll add more. Compost retains water much better than clay and gives nutrients to the soil that the plants can then use to grow and produce fruit. However, adding compost is only part of the solution.

Making the First Terrace

     Lindsay wrote about disassembling the pigpen to create the retaining wall for the first terrace. Making a terrace is not as simple as it seems, but it is a worthwhile investment.

the first of the short ties and rebar

     We began by tying masonry string from one side of the garden to the other, making sure it was level. Then we dug a trench for the railroad ties (which used to be part of the pigpen) by referring to the level string. On one end of the garden we had to dig a rather deep trench, but on the other end we didn't need to dig at all. What we did have to do was to make sure that the bottom of the trench was angled towards the terrace we are building so that the wall would tilt into the soil a little, giving the structure more support.

terrace diagram

     Then we hammered the rebar into the trench every 18 inches, since the railroad ties already had predrilled holes with that separation. Sometimes we'd run into rocks and would have to stop and dig them up. Sometimes, though, we were lucky and the rebar went into the ground smoothly.

driving home the rebar

     The next step was to slide the railroad ties onto the rebar. We found that some of the railroad ties were too long, so we put in the ties as well as we could and Walt volunteered to chainsaw the ends so that they would all fit snugly. We built three layers of ties. Then we used the maul to hammer the rebar into the ground as far as it would go. Our interlocking railroad-tie retaining wall is looking pretty sturdy.

new snow graces the new retaining wall

In the meantime...

     Lindsay and I have been musing on the concept of reuse during this process. The pigpen, a circular structure, was disassembled and recombined into a long straight wall. All the components of the pigpen are still there, except that now they make a wall. The earth works in this way at its most fundamental level. When you die, your atoms disassociate and are formed into plants, perhaps, or are carried down a river. The plant is harvested and shipped to New Jersey (say) and some person in Hoboken eats it. You're a part of them now. That's essentially what happened with the pigpen. Sustainability is all about convincing a pigpen to make you a wall.

  March 22:

     After the retaining wall went up, the uppermost terrace was still not level, so the water would continue to flow down the hill if we didn't do something about it.

     So we did something about it. Andrew, Camille, and I spent an afternoon moving earth from the high places to the low places of the terrace to even it all out. It was a lot of work, but it will be worth it once our water usage is more efficient in growing healthy plants. Since the hill that the garden is on slopes north-to-south as well as east-to-west, we made sure that the north-south slope was level. We can use the east-west slope to our advantage by allowing water to flow in that direction in a controlled manner. We intend to build up the slightly shorter side with compost as time goes on to even out the east-west slope eventually. The garden is an intentional landscape.

lookin' better

     Camille and I used the surveying tools Opalyn has for making measurements to see whether the terrace was level. First, I measured my eye height by using the hand level and looking at the measuring rod while both Camille and I stood on level ground. Then, I stood on the north side of the terrace as Camille placed the measuring rod on the south side of the terrace. I looked through the hand level again and found that the measurement was larger. This meant that the north side of the terrace was more elevated than the south side. We compensated for that by adding more earth to the south side.

Camille and I measure differences in elevation

     So we're done with the first terrace. Whew! Two more to go...

Camille lends scale to the terrace

Notes From Windward - Index - Vol. 69