Grower of giant produce shares tips for cultivating healthy soil

Six-foot long gourds, 20-foot tall sunflowers, and 1,000 lb pumpkins might sound like science fiction, but these supersize plants flourish in Chris Brown’s backyard. An avid gardener from the town of Nowthen, Minnesota, Chris took first place in this year’s Minnesota State Fair Giant Pumpkin Competition when his brilliant and beastly orange pumpkin weighed in at 1,104 lbs. “I tell kids at the Fair that I’m growing Cinderella’s Carriage,” he says with a grin.

Seven years ago, Chris was visiting the Horticulture Building at the Minnesota State Fair when he was struck with the desire to grow giants. He transitioned his kitchen garden into a plot dedicated to massive pumpkins, squash, tomatoes, and more. His regular applications of manure, compost, and leaves help keep the soil rich and hospitable to beneficial soil-dwelling critters.

This is the key to Chris’ success: a holistic approach that maintains a healthy environment for microbes and tiny organisms living in the garden soil. In recent years, he is increasingly convinced of the important role mycorrhizae play in supporting robust plant growth. Mycorrhiza is a kind of fungal root that grows in a symbiotic relationship with plant roots.

Mycorrhizae are ubiquitous in soil, and they help channel nutrients from the soil into the roots of their host plants. Giant produce plants are voracious feeders, and after a typical year of growing giant pumpkins, the soil in Chris’ garden is depleted. Adding compost, manure, and leaves in the fall helps the soil to regenerate robust populations of microbes — and it keeps the organisms that live in the soil happy.

Thriving ecosystems start with living soil

These days, commercial farmers, giant growers, and hobby gardeners are all paying more attention to the importance of healthy soil. Conventional lawn care and gardening practices neglect or actively harm living soil through use of chemical treatments and tilling that leads to erosion.

When gardeners reduce tillage, microbes in the undisturbed soil can feed on residues and plant material underground. Roots and microbes excrete organic matter that allows water to infiltrate and helps the soil hold moisture for longer. That’s crucial in droughts like we experienced in 2021. Living soil doesn’t just absorb and maintain water — and it also helps filter water, reducing potential pollution in runoff from heavy rain falls.

Of course, not everyone is growing vegetables to set world records or win state fair ribbons. If you’re growing an herb garden, vegetables, pollinator-friendly flowers, or even a lawn, following principles for healthy soil will help your plants thrive. A soil test is a great tool to implement to improve soil health and reduce any unnecessary fertilizer application. Check out these recommendations from the University of Minnesota Office for Soil Health:

• Keep soil covered: This fall, cover garden beds with a three-inch layer of shredded leaves to replenish the soil over the winter.
• Minimize disturbance: Limit your digging or tilling to just one or two inches of topsoil. Deep tilling increases erosion and destroys soil structures that support robust plant growth.
• Keep roots in the ground: When you eliminate tilling, microbes in the soil will feed on roots and organic matter left in the ground. The result is porous soil that allows water to infiltrate.
• Diversify plant rotations in veggie gardens: This basic practice of changing which plants are in a certain location year after year helps minimize soil nutrient depletion and reduces unwanted pests.