Living Soil and Planning Your No-Till Garden
Last month we talked about mulch; its benefits, the different options available to us and the advantages and disadvantages they offer. This month I would like to focus on methods for turning over beds as discussed in Jesse Frost’s book “The Living Soil Handbook. Turning over beds is essentially completing the harvest of one crop and preparing to plant another in that space. For most of us, we grew up with tilling the soil being an essential step in that process. In order to change how we prepare the soil to plant, we also may need to modify how we harvest.
If possible, it is best to leave the roots in the ground after harvesting. Of course, this does not work for every crop, such as garlic, carrots or radishes, where the crop we are harvesting is below ground. In those situations, you would indeed pull up the entire plant for harvest. However, for many things we grow, our harvested parts are above ground only and the roots can be left intact. By leaving the roots you allow the community of microbial life that you worked hard to establish continue to thrive. That being said, the plant needs to be killed in order for it to not compete with your next crop.
There are several ways to accomplish this. It can be done by cutting the stem at or slightly below the soil line with a hand tool (snippers, lettuce knife, stirrup hoe). It can be done using the process of occultation (using an opaque covering over the ground to kill any remaining plant life.) Occultation can be done using a silage tarp, plastic sheet, landscape fabric or cardboard. In some instances, the occultation material can be left in place and small holes can be cut into it to place your new crop transplants. Crops can also be terminated using the bush blade on a string trimmer, which will allow you to trim large numbers of plants at the soil surface (the bush blade is preferred so you don’t leave plastic bits from the string in your soil.) Market gardeners might find it worthwhile to invest in a flail mower (a mower that spins on a vertical plane as it cuts, as opposed to the horizontal spin of traditional mowers.) Another option is solarization, which involves laying clear plastic down over the plant residue to kill the plants using the sun’s radiation. Depending on the time of year, this method can work within a day to a week, vs several weeks using occultation.
These methods can be more time consuming than just running everything over with a tiller, but for soil health the important thing to remember is that you terminate the current crop while disturbing the soil as little as possible. Next is the opportunity to add any organic fertilizers or mulch on top of the soil and lightly rake in if needed. Then replant as quickly as possible. Depending on what you have remaining in the soil and what you are planting next, you may choose to maintain your plantings in the same rows as before and just plant in the spaces between the old plant roots. Or, you may choose to make new rows in the spaces between the old ones. For root crops, this becomes more important as the presence of old plant roots can interfere with the growth of the new crop. Consider this when planning your planting rotation. Plant carrots and other root crops after shallow rooted, tender crops such as lettuce for better results.
Submitted by Melissa, NEW Master Gardener
