The future of commercial farming, especially in Maine, is in protected agriculture, meaning crops grown in greenhouses and hoophouses. This is according to Cornville farmer and greenhouse farming expert Andrew Mefford, whose new book deals with the subject.

“The Greenhouse and Hoophouse Grower’s Handbook: Organic Vegetable Production Using Protected Culture” provides enough detailed information for a commercial farmer who wants to begin protected farming in a big way. It also offers solutions simple enough for a dedicated home gardener who seeks more production and self-sufficiency.

“There is so much pressure here because we have such a short garden season that it really helps to be able to spread it out,” Mefford said in a telephone interview earlier this month, not long after his book was published. Greenhouses and hoophouses allow gardeners to plant earlier in the spring and harvest later in the fall.

Beyond that, growing in greenhouses is more environmentally friendly than field growing, he added, even if the greenhouses are not certified organic. Pesticide use has become rarer in greenhouses and hoophouses because its use is counterproductive, Mefferd said. To begin with, after using the chemicals, a period ensues when people can’t enter the greenhouse and plants can’t be harvested. Next, while the pesticides kill the harmful insects, they also kill the beneficial insects that most greenhouse growers rely on.

“The Greenhouse and Hoophouse Grower’s Handbook” provides information to help people grow crops successfully in a simple, 100-square-foot hoophouse or in a heated, automatically ventilated greenhouse that covers an entire acre.

“The book is sort of an a la carte offering where people and pick and choose what works for them,” Mefferd said. “The book, I think, would help people especially who have a part-time job growing for a farm market who are thinking of making the leap to becoming a small to medium-size commercial grower.”

He includes techniques used by some of the largest and most successful commercial protected horticulture growers, and he shows how those techniques can be done on a smaller scale.

Mefferd draws directly on his personal experience. He explains that after two years attempting to grow tomatoes at the farm he and his wife run in Cornville, he concluded that to grow tomatoes successfully in central and northern Maine, it must be done under cover. Greenhouses and hoophouse not only provide more heat, they also provide protection from some diseases.

The book also benefits from the seven years Mefferd spent working in the trial gardens of Johnny’s Selected Seeds in Winslow – work that included conducting trials on which plants work best when grown under cover and how greenhouses increased production of various crops.

The book has chapters on the best methods for growing specific crops in greenhouses. Tomatoes, peppers, cucumbers and eggplants each get a separate chapter, while a chapter on greens encompasses lettuces, other greens, microgreens and herbs. Mefferd, a self-described “tomato-head,” devotes most time and space to tomatoes, which he says are the most profitable crop to grow.

The book’s advice isn’t limited to growing in greenhouses. And some of it is simple: Growers should remind shoppers never to store tomatoes in the refrigerator, which will ruin their flavor. That type of customer service is one way that local growers can make sure their produce is not treated like a commodity, Mefferd writes. Other ways to decommodify produce are to stress to customers that the food is local, organic and tastier and that the grower has different varieties of crops than are typically available elsewhere.

One of the longest chapters in the book centers on grafting vegetable plants, especially tomatoes. Mefferd said many of the questions he was asked while working at Johnny’s involved grafting tomatoes, so he decided grafting deserved a chapter. Grafting, more common with fruit trees, is when a one species of a plant is joined to a different species. Usually, the root stock offers higher disease protection, while the above-ground part is chosen for its production and/or flavor. Mefferd says using grafted tomatoes improves disease-resistance, production and flavor – both inside and outside the greenhouse.

Mefferd spent most of 2015 writing the handbook because he knew he would soon be starting work as editor and publisher of “Growing for Market” magazine, as well as operating his own farm. He left Johnny’s in November 2015.

What he did not realize was that the editors at Chelsea Green would ask for a major rewrite.

“It is a much better book after the editors had me reorganize the book and get rid of some of its weaknesses,” Mefferd said, “but 2016 was just crazy busy.”

With the book now out, he has only two jobs: co-owner of an organic farm and editor and publisher of a monthly magazine. That seems like enough to keep him busy.