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A New Garden Model by Nigel Palmer The following excerpt is from Nigel Palmer’s new book, The Regenerative Grower’s Guide to Garden Amendments: Using Locally Sourced Materials to Make Minerals and Biological Extracts and Ferments (Chelsea Green Publishing, August 2020) and is reprinted with permission from the publisher.
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e all use models to help explain the world around us. For example, when a traffic light turns green, many of us reflexively hit the accelerator and go. We don’t check whether any cars are coming from the left or right, because our mental model assumes that cross traffic has stopped. Another example: At day’s end, we don’t worry when the sun goes down and it gets very cold, because we have a clear certainty that the sun will rise again tomorrow morning, providing light and warmth. Our mental models define our reality. We tend our gardens and farm fields 46
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based on our mental models about how plants grow. An example of a plant cultivation model is the assumption that simply putting a tomato seed into the ground, and occasionally watering it, will eventually produce a tomato plant that bears a good crop of fruits. Some gardening and farming models require that the soil be tilled and all weeds removed before seeds can be planted. Some models call for regular additions of nitrogen fertilizer and lime. Plants are tenacious, they will grow under the most difficult of circumstances, and even if a cultivation model is far from ideal, the plants may grow pretty well. Many a good-tasting tomato has been grown following conventional gardening models, but are these the most nutrientdense tomatoes possible to grow? Can the nutrient density of the crops grown be measured? The answers to these questions lie ahead. Rediscoveries of forgotten or discarded ideas about plant growth—such as that truly healthy plants can thwart soilborne and airborne pathogens, as well as insect
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pests, and provide significantly higher levels of nutritional value—are the inspiration for a new model for tending gardens and farm fields, one that focuses on the entire ecosystem that the plant grows in. And from these ideas arises a new garden model that makes use of a different set of tools and gardening practices. The old plant model that most gardeners followed for decades envisions a one-way flow of nutrients from the soil into the plant, with no biological interaction involved. In this model the soil isn’t given much importance—it’s just a matrix for root growth. Gardeners add nutrients to the soil in the form of fertilizer. Plants absorb those nutrients through their roots, and the plants produce a harvest. Gardeners also remove weeds that might rob the crop plants of the costly fertilizers so carefully applied, and they use sprays to kill pests and disease organisms that might attack the plants. A new model of plant growth is based on a two-way flow of nutrients between soil and plant and an understanding of a
