At bottom, gardening is all about dirt — its care and feeding, its microbes and fungi, bacteria and earthworms.
Science has gradually recognized that the soil’s vibrant but delicate food web must be treated carefully to produce the best yields. Turning the soil before planting is generally conceded to be more disruptive than building it up year after year with rich natural substances.
“We lose organic matter whenever we till the soil,” said Mark Alley, an agronomist and professor of soil fertility and management at Virginia Tech.
No-till growing means adding layers of plant and animal matter to the topsoil rather than plowing, shaping and otherwise disturbing it.
“It reduces runoff and evaporation losses, increases organic matter in surface soils, which increases the rooting environment for seeds,” Alley said. “All this makes things more productive.”
Farmers began to embrace the no-dig philosophy in the mid- to late 1970s with development of a no-till corn planter, said Brian Jones, an extension agent for Virginia’s Augusta County.
The same planting principles apply to back yard gardens. They vary from farm fields only in scale and in varieties grown.
The first year is the hardest for no-till practitioners. The ground must be cleared of debris, weeds and other obstructions before nutrient-rich compost and protective mulch can be used.
“Initially, some digging of perennial roots may be required,” said Charles Dowding, a commercial gardener and author of “Organic Gardening the Natural No-Dig Way.” “If the soil is full of durable perennial weeds, a long-term (smothering) mulch for a year is worthwhile. It becomes much easier thereafter.”
The essence of no-till gardening is staying ahead of weed growth, not allowing weeds to seed and creating a clean plant bed with just a few weed seeds germinating, he said.
Because no-till encourages the soil food web to become so active, fewer nutrients need be added, and only soils with deficiencies will require synthetic minerals, he said.
Digging up the soil to destroy weeds is a failed practice, said Jeff Lowenfels, a lawyer from Anchorage, Alaska, and co-author of “Teaming With Microbes: A Gardener’s Guide to the Soil Food Web.” It only encourages weed growth by exposing seeds to sunlight, he said.
“Heck, we’ve all seen plants grow through pavement,” Lowenfels said. “They don’t need tilled soil. The least amount of disturbance when planting in a garden is best.”
Dowding recommends that gardeners new to a no-till system begin with a small area and experiment to find their favorite growing methods. “If it seems strange or difficult at first, do persevere, because the potential rewards are significant, especially the reduction in weed growth.”
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