Time to Improve the Soil?

How is your garden doing this year? Are your plants healthy and strong and yielding a bumper crop of fruits and vegetables? Or are they looking rather thin and not as productive as you’d hoped? What could be the cause? The plants seem green and healthy. You haven’t detected any insect damage or fungal growth. You water carefully – not too much and not too little – and you make sure to water early in the morning and direct that water to the roots. You’re doing all the right things, yet your garden’s productivity is not quite what it should be. So what in the world could be the problem?

The answer may lie right at your feet – namely, the soil on which you are standing. (Note: try not to stand or walk on the soil too much; it compresses it). Soil is nature’s pantry, and just as you have to go grocery shopping to replenish your pantry with food items to replace what you have eaten, so you must also replenish the soil to replace the nutrients that your crops have absorbed. Soil is not a finite quantity. It must be replenished continually with organic matter to maintain the cycle of life. In the wild this happens naturally. Plants die and get broken down by bacteria and fungi. This returns precious nutrients and organic matter to the soil, maintaining its health and structure, and providing life for new plant growth. But our gardens require human effort to do what nature normally takes care of, and oftentimes, we forget this. So if your garden is not quite performing like it used to, it may very well be that the pantry is bare and needs replenishing.

So how does one go about restocking the cupboard, so to speak? Well first let’s talk about how not to do it. Many people try replenishing their soil by applying concentrated chemical fertilizers. This may give your plants a quick boost, but it will not last long. Just as a drug addict gets a quick high from a hit of heroin then crashes, so too will your garden crash after an application of a chemical fertilizer. And just as that aforementioned drug addict needs another hit of heroin to maintain that high, your garden will need continuous hits of that chemical fertilizer to stay green and productive. In other words, continuous use of chemical fertilizers will turn your garden into a drug addict. Furthermore, those heavy concentrations of chemical fertilizers eventually leach into our groundwater, lakes, and streams causing algae bloom and aquatic wildlife kill.

Proper replenishment of the soil pantry is best done by applying organic matter. A six inch layer of compost, humus, leaf mold, earthworm castings, or some combination of the aforementioned will provide food for the soil’s web of life – earthworms, bacteria, nematodes, etc. – which will then break it down and release the nutrient matter which your garden vegetables can then soak up. In addition, this organic matter will provide “stuff” to go between the mineral particles, thereby breaking up heavy clay soils, making them looser and lighter and easier for your vegetable crops’ roots to penetrate the soil.

Another way to replenish the soil is to grow what are known as cover crops or green manure plants. These are crops that are planted for the sole purpose of being dug up, chopped up, and worked back into the soil. Besides providing that organic matter to improve soil structure, some green manure plants have special properties. The large roots of daikon radishes can penetrate heavy clay soils, breaking them up. Legumes such as alfalfa, clover, and hairy vetch form symbiotic relationships with certain soil bacteria that can pull nitrogen from the air and convert it to a form that plants can use. Lastly, cover crops can crowd out weeds, thereby reducing your weeding chores.

The best time to apply organic matter is in the fall. Add a 2-4 inch layer of organic matter on top of the soil and either work it in or, if you practice no-till gardening, simply leave it there. Then, you will have three months of winter for the soil microorganisms to break it down and release nutrients to the soil. Come spring, you have loose, light, healthy soil all ready to be planted. If you wish to utilize a cover crop, plant it in September or October to give it time to germinate, grow, and overwinter. In the spring, chop it up and work it into the soil (do this as early as possible before the crop sets seed).

We all want our gardens to produce a bountiful harvest, year after year. By regularly replenishing your soil with organic matter, you can ensure that your garden will continue to be productive for many years to come.