Greenhouse – Glazing

Q: A tornado damaged my greenhouse; it was wiped out even with the ground. I am in the process of buying a new one and need to know if I should get it with “clear” or “mist green” fiberglass exterior. I don’t understand the advantage or disadvantage of either.

A: Paul Thomas University of Georgia horticulturist replies:

“Mist green does filter out some green light wavelengths…this is not important as plants reflect these wavelengths anyway. Secondly, fiberglass breaks down over time and becomes cloudy…mist green darkens quicker. I would use polycarbonate coverings, preferably double cell polycarbonate to save energy, and have better structural control. You’ll save the difference in price in less than a year with heating cost reduction. The clear is the best choice…in winter we need every photon we can get. There is no advantage to the mist green that is worth considering. You already know about shade cloth, so maximize your light.”