THERE are 18 in the class, and 18 hands shoot up in an eager response to the visitor's query. ``It's a Grow Lab,'' they say, pointing to a plant-filled structure bathing the far corner of the room in a soft, luminous glow. The enthusiasm is obvious, and there's not a bored look anywhere. They are only in the second grade here at the Orchard School in South Burlington, Vt., but they know all about germination, pollination, how peanuts grow, and what a cotton plant looks like; that a nasturtium may look pretty but also tastes good in a salad. And they speak with authority on photosynthesis.
``It's how light makes the plants grow.'' Then more explanation: ``When we breathe out carbon dioxide, the plants take it in and give us back oxygen. They want our carbon dioxide and we want their oxygen.''
Less obvious to the eager youngsters are the nonhorticultural lessons the indoor greenhouse is teaching them; lessons in math, environmental studies, even the social sciences, and in creative writing, says their teacher Paula Flaherty.
``It's an all-round teacher's aid; the springboard for so many other subjects,'' she adds. Then with a chuckle: ``It's also the envy of the school.'' And so it has proved in the 74 other classrooms around the United States that were introduced to the Grow Lab program by the nonprofit National Gardening Association last year.
About 12 months ago, the NGA, backed by the National Science Foundation, launched a pilot program aimed at helping schools put across the fundamentals of gardening and horticulture. Basic to the program is the Grow Lab - a specially developed system of lights for indoor growing.
Feedback from the schools in 11 geographically diverse cities has been uniformly excellent, according to NGA president Charles Scott, and the association is preparing to launch the program nationwide. The immediate aim is to give a minimum of 5 million schoolchildren each year the opportunity to learn in this fashion. Ideally, every child in the country should get some exposure to the program, Mr. Scott says, adding that even if it is never achieved, it is ``something to aim for.'' Already the youngsters who will shortly be getting the experience are several times as many as the NGA originally contemplated.
Three years ago, the NGA staff made a commitment to concentrate on youth gardening and began looking for an existing educational program that could involve teachers, administrators, and the nonprofit organization. They found what they sought in Hartford, Conn. There the little-known Knox Park Foundation had established indoor gardening projects in schools using a simple box containing the growing medium, over which were strung some artificial lights.
The concept was attractive because it freed the learning system of climate-imposed limitations. Seedtime and harvest could be planned to coincide with the school year rather than requiring children and staff to harvest during the summer vacation. Other advantages: No land was required, opportunities to vandalize were minuscule, and there was a captive audience. So NGA entered an agreement with the Knox Park Foundation that allowed it to present the program to a wider audience.
First the equipment had to be upgraded to meet electrical codes nationwide. Light intensity was increased by adding reflectors. Climate controls allowed classes to reproduce everything from a rain forest to a desert.
Initial tests in a handful of schools showed that prototype Grow Labs were so popular that they were being moved from class to class at three-month intervals. So, Scott says, ``We had wheels added.''
Currently a curriculum is being developed with input from teachers around the country. It will be available next year. Meanwhile, the Grow Lab system was officially introduced last month at the National Science Teachers' Association convention in St. Louis.
The experience of Mrs. Flaherty and other teachers will help shape the curriculum. When seeds are planted on Monday and they come up on Tuesday of the following week, how long did they take to germinate? she asks her class. If the lights are on in the Grow Lab 16 hours a day, how many hours are they turned off? ``The children don't know it, but they're learning math,'' she points out. When they write down their feelings about the Grow Lab, they're involved in creative writing.
``Now,'' says Flaherty, ``none of my class still believe the food chain begins and ends in the supermarket.'' With the help of the Grow Lab they now know that food is often transported vast distances to consumers.
``And that's a lesson in social science!''
For information on the Grow Lab system, write to the National Gardening Association, 180 Flynne Ave., Burlington, VT 05401.