Eavesdrop on pupils in many middle school cafeterias and you might hear a vigorous debate about the relative merits of strawberry vs. raspberry Pop Tarts.

But not at Troy Howard Middle School.

On Thursday afternoon, a dozen seventh-graders could be heard touting the nutritional value and superior taste of their home-grown greens to the district superintendent, assistant superintendent and the managers of the district’s food services.

In the fall, the middle school's renowned Garden Project program launched its first attempt to grow spinach and other salad greens through the winter in an unheated structure. Even with subzero temperatures this week, the project's new "hoop house" produced about 40 pounds of greens.

The pupils served samples to the district administrators gathered in the school library --- greens flavored with Newman's Own dressing --- hoping to persuade them to feature the produce in salad bars at the high school.

Garden Project greens and root vegetables already are offered at all the district's elementary schools as well as in the middle school cafeteria. The produce is sold at the Belfast Co-op Store and to district staff, and donated to the local soup kitchen.

But to date, the project relied on a heated greenhouse.

The latest venture, explained Steve Tanguay and Jon Thurston, who coordinate the project for the school, was to test the viability of an inexpensive, unheated structure to grow through a Maine winter.

After building the hoop house --- it's 12 feet wide, 20 feet long, and 8 feet high at the peak --- and covering it with special plastic, all for about $800 from a grant, pupils considered the soil bed options and planted their crop.

The latest venture had pupils using math, science, communication and analysis skills as they tackled the design, materials and construction of the hoop house, and observation of the conditions inside and out, and the results of the crop.

Pupils also used the latest in microscopic photography equipment to record images of ladybugs eating aphids and wasp larvae growing out of aphid carcasses, which they projected on a screen at Thursday's event. The children took turns with portions of the presentation and talked comfortably and knowledgeably about the material.

Each portion of the project was tied to Maine's Learning Results standards, Tanguay and Thurston said.

Data from indoor and outdoor temperature probes were carefully tabulated. The cold snap Wednesday night resulted in an outside low of 7 below zero, while inside, temperatures in the soil remained in the 20s, which is tolerable for the vegetables being grown.

Tanguay and Thurston said the same set-up could be used by a typical family to produce the same 10-20 pounds of greens weekly to augment its diet. The project has relied on help from noted Maine four-season gardener Eliot Coleman, they said.

The latest part of the garden effort also had pupils using the art of persuasion.

The middle-schoolers traveled to Belfast Area High School to informally survey the older students about their perceptions of the garden greens. The high-schoolers were asked to compare the organic garden greens to iceberg lettuce, which is typically offered at the cafeteria's salad bar.

On both visual and taste appeal, the locally grown greens won favor with high school students.

And it's hard to argue with the nutritional value of the spinach-heavy mesclun salad mix, which pupils said provides three times as much protein, five times as much calcium, six-times as much iron, seven times as much vitamin C and 20 times as much vitamin A as the iceberg lettuce.

Asked if they have changed their eating habits as a result of being affiliated with the garden project, pupils were thoughtful.

Lila Carpenter said she had developed a taste for fresh spinach, while John Loxterkamp admitted to enjoying munching on raw corn.

Forrest Munson conceded she was not a big fan of salad, but "now, I like it." Nick Flagg also admitted to being a salad convert.

The other pupils involved in the presentation were Rochelle Soohey, Emma Boniville, Rose Hyland, Kate Howard, Carson Beck, Alex Blair and Noah Fishman.