Tuesday, February 14, 2012

The Out-of-Season Season

This time of year, everything seems to be out of season locally. My most recent visit to Three Rivers Market turned up no local produce items, other than storage sweet potatoes. Given that I am harvesting herbs and greens from both outdoor beds and my cold frames, you'd think someone would be doing this commercially.

Last month, there were plenty of local green crops on the shelves. So why now a dearth? I can think of lots of possible explanations. All of which boil down to a matter of timing on the grower's part. Hopefully, some enterprising farmer will realize that he or she could sell local produce during February and plan accordingly next winter.

Cabbage plants under artificial lighting
In all fairness to our astute local growers, it is much trickier to produce a winter crop around here owing to the sporadic availability of sunshine. Short days in December and January cause crops to slow down and stop growing. I have experimented with various types of supplemental lighting for years. Given our relatively low electric rates in the Tennessee Valley, about 9 cents per kilowatt/hour for residential customers, growing winter crops with supplemental lighting might be cost effective for an efficient operation.

It would be interesting to compare the carbon footprint for producing local crops with supplemental lighting, versus trucking the same crops long distances. I know, for example, that lettuce can be grown to harvestable size entirely under fluorescent lights. The photo at right shows sturdy lettuce plants now about a month old. And below, Ashley lettuce, grown under lights, has reached leaf lengths of about five inches, big enough for a salad. These plants are going out to the cold frame soon, but if they were potted up and left under the lights they would mature. Lettuce produced indoors has a much more tender texture. The leaves are thinner. We are experimenting with air movement to get a crispier lettuce. By using a small fan to gently circulate air around the leaves, we encourage them to become sturdier, and hence more palatable.

Lettuce 'Ashley' under fluorescent lighting
Home and commercial growers alike should experiment with supplemental lighting. New technologies, such as LED lighting arrays, offer promise of space-saving designs that use a fraction of the electricity of currently popular equipment, such as fluorescent and metal halide lighting. The biggest drawback to LED systems for home use is their high initial cost, but the price should come down as the equipment gains in popularity.

No comments: