In my small greenhouse, I’m growing the two herbs that we like to use in the fresh state, Italian parsley and basil. In the winter, because of it’s low position on the horizon, the sunlight is less than half as intense as it is in the summer. Add to that the fact that the sunlight is passing through polycarbonate sheeting, further reducing its intensity. The basil looks mostly normal, maybe a little leggy. Everyone knows about phototropism, the growth of a plant toward its light source, but many people don’t realize that some plants grow larger in lower light than they would in intense light. For example one of my Italian parsley plants has grown very large, with individual leaves measuring 3 inches long and 2 1/2 inches wide, about twice the normal size. And the plant, pictured below, is now 22 inches high. The explanation for this is that the large leaves of the low-light plant provide a larger area for trapping light energy for photosynthesis.
