This is the first post of a weekly series I’m calling “Natural State Gardening.” Look for posts each week, usually on Friday.
Creating healthy soil for your plants is the most important thing you can do for them. So, what makes soil “healthy”?
Though each plant has its own preferences, plants generally need a variety of macro- and micro-nutrients to thrive. The essential macronutrients are: nitrogen (N), phosphorus (P), and potassium (K). Micronutrients include iron, boron, and zinc. So, what do we add to the soil to organically feed these nutrients to the plants?
A well-made compost—regularly applied—will supply most of the needed nutrients to the soil. However, a free soil sample from the local extension office might reveal that the soil is deficient in certain nutrients. If so, there are many organic remedies:
- Nitrogen: rotted manure, cottonseed meal, alfalfa meal, legume cover crops (“green manure”)
- Phosphorus: rock phosphate, bone meal
- Potassium: greensand, crushed granite, wood ashes (from fireplace or stove), leaves
NOTE: A soil test may also reveal that the soil pH is out of balance. Most garden veggies prefer a pH between 6 and 7. If the pH is lower (more acidic), add limestone (“lime”). If the pH is higher (more alkaline), add acidic materials to the soil, such as peat moss, leaves, sawdust, or bark.
At the Heights Neighborhood Garden we are using compost (many nutrients), greensand (potassium and many micronutrients), and rock phosphate (phosphorus). These amendments provide the soil with a good “insurance policy,” according to Eliot Coleman—one of the nation’s best farmers. In other words, we want to make sure these nutrients are in sufficient supply (especially phosphorus, which is the nutrient most likely to be deficient in the soil), so we add extra. But, why does it matter that we use organic soil inputs instead of synthetic chemical inputs?
We use organic soil inputs to encourage soil microbes to thrive. These microbes take nutrients from the soil and feed the plants, which are otherwise unable to get the nutrients they need. On the other hand, synthetic chemicals kill the soil microbes and make the plants dependent upon a constant supply of chemicals. Those chemicals can be expensive, easily contaminate our water supply and be toxic to your health.
Basically, we gardeners are doing our best to mimic nature, where animal droppings, leaves, branches, and other organic matter constantly breakdown and add nutrients back to the soil without human interference. Like nature, if we feed the soil properly, the soil will feed the plants properly.