One thing that I love about farming is that it is extremely dynamic. No season is exactly like the last season, and I am always looking ahead to the new season even before the current season ends. Recently while I was plotting new strategies for the farm in my head I decided to look for some new inspiration. I found just the inspiration I was looking for when I discovered the Instagram page of a gardener in England named Charles Dowding.
Charles is an author, instructor, and advocate for the no-dig method of gardening. His approach is to build upward on top of the soil, rather than till or flip the soil at the beginning of the season. I was intrigued when I started to read his online content and book. Rather than pull the weeds in the garden plot, or till up the soil to start anew, his approach calls for cardboard and a hefty amount of compost. A light bulb came on in my head as I excitedly envisioned the perfect spot to test out this method on the farm.
Last Fall I plowed a new section of the farm and formed several rows for planting. The season got away from me and these rows ended up turning into a weedy mess, as you can see in these photos:
In the past I would have cut my losses and re-tilled the rows to get rid of the weeds and start with a fresh plot. The problem with tilling too much is that it disturbs the soil structure and every time you disturb the soil you uncover more weed seeds, which just exacerbates the problem. So I turned to my new source of inspiration and decided to leave the rows exactly as they were, but instead of pulling the weeds the farm crew and I smothered them with cardboard:
I would like to point out that this method probably works best if you are dealing with annual weeds, not perennial weeds like Bermuda grass or nut sedge. Those weeds are aggressive and will eventually work their way through the cardboard barrier.
Once the cardboard was applied to the rows it was time to cover the cardboard with a nice thick layer of compost. The type and quality of compost is very important here. You will want to work with a well-aged compost because you will be planting directly into it. Fresh manure or mushroom compost won't work here because the plants won't be able to tolerate it. If you would like to use mushroom compost it will need to be aged until it is not hot anymore.
Once the compost was applied to the rows we filled-in the walkways with oak leaves and/or hay. I wouldn't normally recommend using hay in the field because it can be full of weed seeds and chemicals, but we have a source of some really clean hay so I was okay with using it here. We also applied a layer of hay on top of the compost to prevent it from eroding in the rain while we wait for warmer weather. Our plan is to let these rows sit and smother the weeds for at least a month before we plant our warm season crops directly into the compost in March. The cardboard will become wet and fragile from rain and/or irrigation, which will allow the roots of the plants to eventually break through into the soil below.
The cardboard and thick layer of compost will kill the weeds below and turn them into even more organic matter for the soil. Your plots should be relatively weed free for the season, but a few grasses might sneak through.
I highly recommend checking out Charles' books (featured above) for some great inspiration from a well-trusted gardener. This method can be used on field plots like we did at Ronin Farm, or you could apply this method to flat ground or bordered raised beds. However you choose to utilize this method it is sure to build great soil in your garden and allow you to spend less time pulling weeds.
Written by Corey Wahl, Director of Farm Operations at Ronin Farm in Bryan, TX