I often hear people say, “Bottomland — flat bottomland — is what I want for farming.” Mention mountainsides and the quick reply is, “No, it’s marginal land and too expensive to farm.”
But mountainside gardening or farming does have its advantages:
1. An acre is measured on the horizontal, so there’s more surface area in an acre of mountainside than in an acre of flatland.
2. Mountainside trees have more leaf-surface area exposed to the sun; on flatland, solar energy is delivered mainly to the tops of trees.
3. Mountain acreage usually costs less.
4. A south-facing mountain slope receives more hours of direct sunlight each day (hence, more solar energy) than mountain valleys do.
5. The growing season is longer on south-facing slopes, since cold air sinks into the valleys and longer days mean more heat is stored in the soil. In Western North Carolina, it’s not unusual to gain two frost-free months at higher elevations.
6. The side of a mountain has good airflow compared to the stagnant, flat bottomlands.
7. Gravity can help move water between beds.
Of course, there are disadvantages too:
1. It takes more energy to go up the mountainside (though it is good exercise).
2. Motor-driven machines can’t operate as well on steep slopes (on the other hand, fuel scarcity may soon limit their use anyway).
3. Terraces can be difficult and expensive to build.
Converting a mountainside into a viable agricultural system doesn’t have to entail a big investment, however. The reduced use of mechanical equipment can actually offset some of the costs of terracing. And if there’s timber, it can be harvested for construction or sale.
But trees hold 80 percent of a forest’s carbon, so when you log, you remove most of the system’s growing capacity. That makes soil-building and terracing (to prevent erosion) urgent.
When I cleared my mountainside of timber, I wanted to be sure that I caused no erosion — I needed every bit of dirt for my plants! The forest floor had about two inches of soil packed with small rootlets. I knew that as soon as I cut through this layer, it would open the door to erosion. So before planting, I raked the leaves into contours and scattered grass, wild lettuce, clover and other seeds, plus fertilizer, several times. It worked! Many of the seeds sprouted, creating a cover crop of legumes before any erosion took place.
After clearing the land, I had a huge pile of small limbs left over. I used them to create rows on the contour, helping form terraces. I also arranged some big logs along the terraces, secured with stakes made of highly rot-resistant black locust.
If the goal is to create an orchard, each tree or shrub requires only a small swale behind a short log. Essentially, you’re creating a series of separate raised beds.
There are several ways to make terraces. The conventional — and expensive — approach is to hire someone with a bulldozer. But for some of my terraces, I erected small, 7-foot-long logs vertically in a 2-foot-deep ditch to create a temporary terrace wall. I will now use old automobile tires (filled with dirt and stacked on top of one another, slanting into the mountainside) to construct a retaining wall in front of the log wall. It will be a race between my tire collection and fungus. Hopefully the logs’ decomposition will be slow enough for me to finish the tire wall first.
Because trees contain so much of a forest’s nutrients, burying logs is actually one of the most efficient ways to build soil. Masanobu Fukuoka, a Japanese agronomist and philosopher who’s considered one of the founders of permaculture, proved this through extensive experiments in the mid-20th century (see The One-Straw Revolution, Rodale Press, 1978).
In Colonial times, farmers would put corn into stumps and let the hogs tear the stumps to pieces in pursuit of the corn. I plan to modify this method slightly, putting corn in holes in the ground above terrace walls to entice the hogs to help level the dirt.
Last year I tried the Fukuoka method of gardening, cutting small areas out of the cover crop for planting vegetables, and I’m now an ardent follower. The legumes keep growing, providing a continuous supply of nitrogen to the plants. When we get too much rain, the cover crop absorbs the excess; and during dry times, it shades the soil, reducing evaporation and drying.
To manage a sustainable farm or garden, soil health must be improved each year. Forest soils in this region are usually acidic; most vegetables, however, grow better in neutral or basic soils. The common solution is to add agricultural lime, but it’s been shown that as the amount of organic matter in soil increases, the soil’s pH has less effect on the plants in it.
At this point, let me confess that I am not a fan of composting — I guess I’m just lazy! More importantly, when plants are composted, the aerobic breakdown releases nitrogen into the air. But when animals eat plants, the nitrogen is captured and made available to fertilize new plants. So a rotation of plants and animals seems to be the natural way of sustaining an agricultural system. (Of course, some residential areas prohibit keeping animals, forcing suburban farmers to rely on worms or hidden rabbits.)
And because mountainside farming eliminates the costs of buying, operating and maintaining equipment, more of the income is potential profit. Or, put another way, you can earn less and keep the same amount. And if you choose crops that require more attention and hand labor, you may be able to compete with mechanized producers. Also, by using Fukuoka’s (or someone else’s) organic methods to grow food, you can get a premium price selling to the burgeoning organic market.
Crops to consider include strawberries, berry bushes, fruit trees, asparagus, herbs and any vegetables you want to eat. North-facing mountain slopes may be suitable for growing ginseng, goldenseal and shiitake mushrooms.
Insect pests can be less of a problem on mountainsides too, due to the enhanced airflow and elevation changes. In addition, I built a long bat house on the front of my house that can accommodate up to 500 bats. I also put platforms underneath the eaves for phoebes and swallows — insectivores that happily nest near human habitations.
I’ve also had good results with a combination of Muscovy and Indian runner ducks (the latter, I’ve found, will even eliminate fire ants). On my rooftop, I have a cover crop where the ducks can graze, and I keep my vegetable crops in cages, so the ducks can’t eat the plants while they’re consuming any insects trying to get into the cages. As a bonus, you get eggs: Indian runner ducks outlay the best chickens, and they don’t scratch up the place.
So don’t be afraid to turn a south-facing mountainside into your agricultural dream.
[Rod Rylander grew up on a farm, studied agriculture in college, and was a government agricultural agent in Belize and the Philippines. He lives in Earthaven Ecovillage outside Black Mountain.]