By Elizabeth Smith
Gardeners often ask me if they should till their gardens. I find that gardeners get much better results using growing methods that protect and preserve soil quality and soil structure, and this means no tilling. It’s hard to go wrong if you follow Mother Nature in her gardening practices. Just so you know, she would never be caught behind a tiller tearing up her soil. In nature, native plants and trees grow happily in the conditions of their natural habitat and without needing the soil disturbed. Mulch from leaves and plant matter builds up under the native vegetation, slowly and steadily giving nutrients back to the soil, as well as making the soil more pliable. The “no-till” method is simply learning from nature how to benefit the soil and the microbial life within living soil.
When commercial growers learned to till soil, it created neat rows for wooden tillers pulled by horses eventually being replaced by metal tillers and tractors. Vast amounts of land planted with just one crop could be grown with easy access for the machines. This method was at first very profitable for commercial farmers growing one crop season after season after season. But, unfortunately, we have learned that tilling and mono-culture has many drawbacks: depleting the soil’s natural life (microbial); tearing up the soil structure where the earthworms live and create pockets of nitrogen, oxygen, and moisture for the plant roots; and losing vast amounts of topsoil when it is exposed to the wind, as happened in the great Dust Bowl across the plains of America. With no roots binding and replenishing the nutrients that had always been supplied by diversity in native plants, the soil became more and more depleted. Continuing this mono-culture trend into modern day farming has created the drastic need for more and more chemical fertilizers causing the downward spiral of sterile dirt, no longer able to sustain plant life on its own.
But what if you want to grow non-native plants like tomatoes and kale in our very unique desert? Good news, you absolutely can! The easiest and fastest way is to build a raised bed or use containers, like metal troughs filled with organic soil and topped with mulch. But, if you are planning on starting with our native soil as your growing base, tilling could have a benefit in initial garden bed preparation because growing non-native plants in our native soil will require lots of amending. You will want to add in things like peat moss, coconut coir, earthworm castings and finished compost. These will need to be dug into your native soil so tilling might help with the job.
Another method of creating a new garden in your native soil that causes less distruction is something called double-digging. This is just digging a shovel wide trench along the length of your garden, the same depth as your shovel. Put the soil from the trench in a wheelbarrow. Then use a pitch fork to loosen the soil at the bottom of this trench. Next, throw in a 4 to 6 inch layer of compost, peat moss, etc into the trench and gently work it into the soil. Then dig another identical trench, right next to this first one. As you are digging this second trench, shovel the soil you are removing into the first trench, covering the amendments. Loosen the soil at the bottom of the second trench and add in 4 to 6 inches of compost, peat moss, etc. Repeat this for as many trenches as you need for the length and width of your garden bed. Use the soil pulled out of the first trench to cover the amendements in your last trench. Then cover the top of your soil with at least 2 inches of compost and another 2 to 5 inches of mulch. Mulching your garden is one of the very best ways to build up your soil but don’t make the mistake of tilling or digging it in. It needs to stay as the very top layer so it will keep your soil moist in the summer and insulating the roots from both hot and cold weather by acting like a blanket or sponge. It will also slowly feed your plants as it decomposes and releases nutrients, and will smother weed seeds that may be present.
Once you have mixed your amendments into your new garden bed, you will never have to double dig or till again. Remember, your goal is to feed your soil, not necessarily your plants. You do this by continually building up the quality of your soil using compost, mulching, protecting your soil structure and maintaining aeration. Don’t forget that plant roots need oxygen and loose soil to move around in and grow. The roots themselves will help create more pockets of air too if the soil is not compacted. So don’t walk on top of your soil or it will collapse all that structure and little pockets of oxygen you worked so hard to create. After planting out your garden, hand dig in your fresh kitchen scraps each week to feed all your wonderful microbial soil life so they can keep working at building up the nutrients in your garden soil. Earthworms and mycorrhizae need biodegradable matter to do this and minimal soil disruption from digging and tilling.
If you are interested in learning more, look up “regenerative growing” or “organic gardening” and there’s a movie on YouTube called “Back to Eden” that explains how to keep your soil healthy using mulching. In nature and in our backyard gardens, mulch takes the place of digging and tilling, so try the no-till method and see what you think!
