Late October and mid-November might seem late to be planting salad greens in New Mexico, but a group of New Mexico State University faculty members, students and farm crew were not deterred by custom.

For the third year in a row, they were starting rows of Trout's Back lettuce and Bloomsdale spinach from seed in a dozen hoop houses, also known as passive-solar high tunnels. Six of the structures are located at NMSU's Leyendecker Plant Science Research Center south of Las Cruces and the other six are at NMSU's Sustainable Agriculture Science Center at Alcalde, north of Santa Fe.

When the last of this crop is harvested in late winter or early spring, it will provide the final data in a three-year study of the viability of these low-budget greenhouses for New Mexico small producers who want to grow vegetables in the winter.

This project, titled "Winter Production of Leafy Greens in the Southwestern U.S.A. Using High Tunnels," actually involves 18 hoop houses — in addition to the ones at the two agricultural science centers, there is one at each of six cooperator sites in New Mexico, Arizona and Colorado. The project is funded by a $194,000 grant from USDA's Western division of the Sustainable Agriculture Research and Education program.

The project's lead researcher is Steve Guldan, agronomist in the Department of Plant and Environmental Sciences and the superintendent of the Alcalde science center.

"During an advisory committee meeting a few years ago, Don Bustos, a successful small-scale grower, recommended that more research was needed on year-round vegetable production," said Guldan. "I felt that the USDA's Western SARE program was an ideal source of potential funding for research on this topic."

The project team includes three other faculty members and five Extension specialists from NMSU, plus a Colorado State University Extension agent from La Plata County. Two NMSU graduate students are intimately involved in the project, as well, and will be using data from the study in their master's theses.

"The main goal of the project is to determine the best way for growers who want to engage in winter vegetable production to provide for direct markets such as restaurants, year-round farmers' markets, community-supported agriculture projects, and maybe even schools," said Guldan. "But we want to do it in a way that doesn't require expensive heated structures - and to see if the types of passive solar structures in this study can provide the winter growing environment for some cold-hardy vegetables like lettuce and spinach."

Juliette Enfield is a master's student in PES who has participated in the project since its inception. "We're growing lettuce and spinach because they're two crops that are always in demand, and they're good things to grow in a hoop house because they're the most efficient use of space," she said. "If you plant something like tomatoes, a lot of the space is being used for vegetation, not the actual product that you sell."

"We have two replications of three different designs of hoop house at each of the two science centers," said team member Mark Uchanski, a horticulturalist in the Department of Plant and Environmental Sciences and Enfield's advisor. "The low design is a single layer of plastic covering up the frame of the hoop house. The medium end design is a single layer covered with a second layer, and a fan to blow air between the layers to provide insulation. And then the final, and high-end, design adds several 55-gallon drums, painted black, inside the hoop house that allow for the capture of heat energy during the day and then the re-release of that heat energy at night."

Del Jimenez, NMSU Extension agriculture specialist with the Rural Agricultural Improvement and Public Affairs Project, has been developing low-cost hoop houses for several years and came up with the basic designs used in the study.  The structures measure 16 by 32 feet and feature PVC pipe frames and translucent plastic sheeting. They are equipped with overhead sprinkler systems.