Fallow Your Garden

For centuries, farmers allowed their soil to go fallow, and today’s modern gardeners are now following suit.

This practice supports sustainable gardening, where crop rotation and natural amendments eliminate the need to add artificial amendments. Adding a cover crop after harvest will keep the soil alive and biologically productive.

Types of Cover Crops

A cover crop is any plant that is seeded heavily and thickly to protect and enrich the soil. A growing cover crop becomes “green manure” when it’s tilled back into the soil during planting.

A “forage crop” has grain heads that are harvested for animal feed; its roots are left in the ground to protect the soil. This is an excellent example of a no-till farming technique.

A “catch crop” includes leguminous covers that can “catch” plant-feeding nitrogen in the air and slowly release it back into the soil after being plowed under. Cabbage and cauliflower are two such plants.

If your soil is already nicely rich, but weeds are the bane of your garden, then, after the “winter kill,” consider using the dead plants as a natural weed block. To do this, punch holes for tomatoes, peppers, and any other future plantings in the dead cover.

If you originally sowed the seeds thickly enough, the remaining mat of dead cover should work as an effective living mulch.

Your region will dictate the exact crop you will use for this method as will what you intend to plant the following season, but consider using nitrogen-fixers, like white clover, which can be a permanent “living mulch,” and cowpeas, or non-legumes, like buckwheat and oats. In California, I use Pacific Gold mustard seed to replenish the soil’s depleted nitrogen by cutting and tilling it into the soil when it flowers.

When to Plant

Start by sowing a cover crop in the late summer/early fall that grows rapidly but will “winter kill” when the temperatures drop. Plant the cover crop (after your harvest, of course), so it has time to grow and benefit the soil before you till it under in late winter. Make sure to do this at least four weeks before the first hard frost to help the crop establish roots. If you would rather not plant a cover crop at all, you can always use mulch (e.g., straw, wood, paper) to protect your soil and add nutrients.

Dozens of cover crop systems exist to keep your soil alive after harvest. Check your local regional agriculture extension for native plant alternatives and their applications.

After you have fallowed your garden and getting ready to prepare soil for the upcoming growing season do you till, double dig or cultivate your soil, adding amendments?

In every forest, debris (leaves, twigs etc.) fall from the tree canopies. Then wind, rain, animals and other cellular processes bring nutrients and break down debris for soil to accept as needed. This is “trickle down” fertilizing and a process every forest ecosystem uses that enhances our planet’s life cycle. One acre of healthy topsoil can contain hundreds of pounds of earthworms, fungi, bacteria, protozoa, arthropods, algae and in some cases, small mammals. On average, the planet is covered with a little more than 3 feet of topsoil.

Tilling

Since the invention of the plow, man has resorted to easier forms of planting crops by turning over soil to eliminate weeds, rocks and allowing easier seed and transplanting applications. For example, tilling the rich soil of America’s great prairie has reduced the top soil from 18 feet deep to 14 inches since industrial agriculture began there.

Soil naturally stores carbon. When soil is plowed or tilled under, carbon, in the form of organic material such as plant roots and microorganisms, rise to the soil’s surface. This temporarily provides nutrients for crops. As the soil carbon is exposed to oxygen and sun, it transforms into carbon dioxide, contributing to the greenhouse gas emissions that warm the planet. No-till farming minimizes soil disturbance, which helps keep carbon in the soil. It also enriches soil biodiversity, reducing the need for chemical fertilizers that emit greenhouse gasses.

Tomato Gardeners and Raised Beds

The average home tomato gardener usually is not planting acres of crops; however, they must still consider the healthy biological structure of the soil to obtain optimum results. Raised Beds over existing site soil is the ideal way to address this for most home tomato gardeners.

Build a simple structure to contain your growing medium on top of your existing site soil. 1×8 or 2×12 untreated wooden frames are commonly used. Aluminum tubs, pavers, and straw bales are other alternatives that are available.

With raised beds, existing soil is then protected and not exposed to the elements and would always be covered with a rich layer of organic material. Formulated organic container garden soil can also be used to cover your existing site soil and of course, your own compost that I hope you are making. Tomato plants grow best in soil with a PH between 6.2-6.8. Testing your gardens top soil is always recommended prior to planting. Many home gardeners also use wire mesh prior to placing grow medium in order to prevent burrowing rodents from attacking your plant roots.

If your site base soil is compacted, or you are converting a lawn into a raised bed garden, double digging with a spade does not invert the soil structure profile as much compared to when you roto-till or plow. The soil is never turned in the double digging process, only loosened and slid forward off the spade moving soil from one place to another. The soil biological structure is then disturbed as little as possible. Only the upper 10- 12 inches of the site soil are loosened allowing for increased air and water availability to plant roots and helps access nutrients and bio organisms stored in the base soil.

In a container or raised bed, your top soil will feed/trickle down to your base and create optimal soil structure. Cover crops and good crop rotation will eliminate the need to double dig your garden after every season as only the top 4-6” will need cultivating and amendments.