A Living Classroom in Portland, Maine!

The results are clear; diffused light is best for plants!!!
Garden & Greenhouse Magazine published an article last year that was yet another confirmation of what Udgar Parsons has long known and is the reason for using the type of polycarbonate glazing panels that we use.

Diffused light, or scattered light waves, as opposed to direct or spectral light, is non directional and hence the reason you do not see dome grown plants leaning in one direction. Because they dont need to, they get the full spectrum of the light they need from all directions as diffusion is exactly that: a wrap around light which hits the panels as a much stronger beam. As it passes through the panels it becomes distorted light, spreading it out and making it much softer for the plants than the harsh rays that come through glass, acrylic or single wall polycarbonate. It reaches all parts of the plant leaf and is not blocked by other plants, or too concentrated in one area.

This, coupled with the silver reflectix inside the dome, and the light colored wooden frame, means the dome contains the least amount of shadow as mentioned in the article. The beds are often made from darker materials which bring heat absorption near to the roots and provide much needed warmth in winter - in addition to the soil heating system, this means plant growth in winter is still viable.

If you try the *acid test* mentioned in the article, taking pictures and looking for light patterns which highlight glare or shadow, you will note that all of our pictures on our website are free from such indicators of non-diffused light in most regular greenhouses. In fact we have a very soft, even lighting in our pictures which is a clear indicator that our glazing really trips the light-fantastic and makes our plants healthy and happy.

Temperature Graphs
We have known a long time that the dome stays appreciably warmer than the outside, but here are some graphs to show how well it performs.