Two hundred years ago, if a family had extra available cash, it was spent on a garden, for the purpose of improving the food the family was eating. Today, if a family has extra available cash, it’s spent on a second house or additional car, and the family continues to eat the same old junk food.
Though I have succeeded with varying degrees of success during specific parts of the gardening season, my gardening prowess has had much impact on our annual family food budget. I know families whose gardens make a significant impact on their diets, but it is nearly a full-time job for one person.
Some studies have been conducted on how much space is necessary, in a highly productive garden, to be able to feed one person. The folks at Ecology Action in California estimated that 4,000 square feet (one-third of a football field) of highly productive soil, growing 60 percent grains, 30 percent root crops and 10 percent greens, could feed one person a healthy diet for one year.
The key phrase here is “productive soil.” The folks at Rodale Institute (who publish Organic Gardening and Prevention magazines) have found that a 4′ x 12′ garden bed of productive soil (in our general gardening zone), planted continuously throughout a year (except in the most frigid times), will contribute $1,200 worth of veggies to the dinner table. The main factor in productive year-round cultivation is the constant incorporation of nutrients to keep the production rolling.
As humans, it is our nature to want to invest in the things we can see. Investing in soil isn’t the type of effort that offers immediate gratification. I’ve been in the construction business for 30 years, and time after time, I have seen people hesitate to invest in repairing termite damage or rotted sills in their house because the work and effort can’t be seen when it’s completed. Similar solid foundational investments in the garden aren’t readily apparent as you make them — but this is the only way to get a sustainable and productive soil.
As fall approaches, it’s worthwhile to put together a plan to invest wisely in your soil. Here’s what you need to start thinking about.
Take a look at what you’ve got. At Jardin Fou, we have last spring’s kale, which will be cut back severely to create a new burst of growth when the weather turns cooler (and we finally get some rain). There will be some space left open for fall lettuce in areas that will easily accommodate “tunnels” or some other sort of season-extension contraption. But overall, the summer garden will be torn out. Weeds that have been protecting veggies this summer (my lame excuse for not weeding) will be pulled out and composted. A cover crop of Austrian winter peas will be planted everywhere to add nitrogen to the soil by next spring when I turn it under, and to allow us to graze on the tender pea-flavored leaves all winter.
But before the cover crop goes in, I will be adding some important ingredients to make sure that next spring the soil has maximum potential.
It has been shown that 4 percent to 5 percent organic matter in soil can hold 4 to 6 inches of rainfall, while 1.5 percent to 2 percent organic matter can only hold up to 1 inch of that currently rare commodity. I incorporated a significant amount of composted leaves (from the Asheville municipal leaf dump) in my garden beds last spring, and there is no question that the beds that received more leaf compost have endured the current drought much better.
The leaf dump at Catawba Street and Broadway is definitely the local source of choice for cheap organic matter, but there are other amendments that your soil will love and that constitute a pretty reasonable investment.
Mushroom compost can be found at Reems Creek Nursery. Bales of alfalfa from your local feed store have high nitrogen content and make killer compost that can be added to your soil when it is half-composted, where it will finish breaking down in the soil during the winter. Stable bedding from horse farms can be picked up free or for low cost, and it always contains a delightful combination of wood shavings, manure and horse urine that absolutely rocks if it’s allowed to break down in soil over the winter. And of course there is compost — biological anarchy in action. Compost takes organic trash and turns it into the best stuff you can lavish on your soil.
Lime is best known for increasing the alkalinity of soil. Most veggies do better in a more-alkaline soil. Spread about 50 pounds over a 1,000-square-foot of garden. I add that amount every three years.
But lime has a physical effect on your soil, as well as a chemical effect. In clay soils, like we have here in WNC, lime causes it to gather groups of finer particles together to make larger physical units in the soil, allowing air and water to more efficiently penetrate the ground.
Dolomite lime is rich in magnesium. Magnesium is an important micronutrient necessary for plant growth, and its presence has the effect of cutting plants’ need for potash.
Wood ashes are rich in lime, as well as potash, but it’s easy to put too much on your garden if you burn a lot of firewood in the winter. Though I burn firewood all winter, I don’t spread wood ashes on the garden because there are better sources for these minerals.
Frugal amounts of pulverized limestone in the compost pile have the effect of helping to speed up the breakdown of green matter.
This is just about the best source of slow-release phosphorus. Super phosphates, available as a manmade alternative, are more water soluble, but lack the overall benefits of the naturally mined and crushed rock form. When rock phosphate is treated with a bath of sulfuric acid, it becomes super phosphate, but in the process, minor but essential elements such as boron, zinc, nickel and iodine are inactivated, so your plants will never benefit from them. You should spread rock phosphate every three years at a rate of 100 pounds for every 1,000 square feet of garden.
Greensand is a mined marine product that has many advantages when added to the soil in your garden. Greensand holds water in the soil and has the ability to make available to plants the nutrients already in your soil that are not being utilized. It provides an abundant source of plant-available potash, which stimulates photosynthesis and rapid growth. And finally, greensand provides trace elements not found in typical garden soils, but which are important for effective plant growth. It won’t burn plants and can be spread at a rate of 100 pounds per 1,000 square feet, every couple years. It can also be spread sparingly in the compost pile to stimulate microbial activity.
I’ve given distribution rates in pounds per 1,000 square feet, but most folks who read this column don’t have that big of a garden. The way you effectively invest in these amendments is to figure how much square footage you do have in your garden. Buy 20- to 50-pound bags of the amendments at your local feed store or garden center (call around to find out who carries them) and store any unused amounts in plastic trash containers with waterproof lids. Fill a coffee can with one of the amendments and weigh it on a bathroom scale to find out how many pounds it contains. A pretty good rule of thumb is that a coffee can of one amendment will cover a 100-square-foot bed.
This fall, take the time to invest in your soil. It won’t show an immediate return, but next summer’s plants will show a noticeable improvement in vigor as a result.