planning captures the sun's heat
There are no mechanical devices in the greenhouse, other than
a small blower used to inflate the two layers of 6 mil plastic
that cover the greenhouse. The blower produces insulation
by creating a create a dead air space between the layers of
plastic. Perhaps more importantly, it also keeps plastic taught
so that it is not affected much by wind. There are no fans
for heating or cooling.
Being solar-heated, the greenhouse capitalizes on solar gain,
stores it in the earth and also is supplemented by the ambient
heat of the earth, which is 55 degrees F (about 13 degrees
"The bigger the greenhouse the less perimeter area there
is to the volume. Because of that you have less heat loss
from the surrounding area. The less heat we can give away
and the more we can store is a better deal."
Proper planning is critical from the beginning. "Light
is the key element to growing in the winter. Even deciduous
trees will shade a greenhouse in the winter. You can give
up hardly any light at all. Make sure that you know your site
and understand the limitations of the sun on the horizon throughout
the whole year. It's really important," he says.
The Gothic arch design gives better penetration of sunlight
and ventilation than the usual half-round Quonset hut style
greenhouse. It is oriented east-west instead of the usual
north-south so that you get the maximum amount of solar gain
with the largest amount of surface facing south, Moore explains.
"The arch design is much stronger than Quonset-style
greenhouses and also sheds snow and ice more readily."
Of course, you can't grow tomatoes in a greenhouse like this
during the off-season, the grower says. But Moore can -- and
does -- grow many other things out of season. For example,
he plants some potatoes inside the greenhouse the day after
Christmas and harvests them in March.
"We are in production from the third week in March and
the week before Christmas when the farmer gets worn out. We
could really run year-round if the farmer didn't get so worn
out, and I think we will have to find a way to do that."
Moore worries about losing customers during his present mid-winter
lull in production. "Whenever you leave and don't serve
that market somebody will fill that void. If you can keep
products going every week through the year it makes a huge