So we laugh about Michael Jackson's "sleeping chamber" filled with purified air, and called Howard Hughes a fanatic for living in a sterile environment. But the question most often asked around the smog-free greenhouse at the L.A. Arboretum is, "How can I get one of these systems for my home?"
The inquiry is understandable after you've looked into the greenhouse--filled with robust plants--which by no coincidence is next door to a greenhouse with normal air. The plants in the regular greenhouse are smaller; some of the leaves are brown, discolored or curling, and the plants themselves are weaklings compared to those dwelling in the smog-free environment. The startling thing is, the struggling plants in the regular greenhouse are breathing the same air we do.
The smog-free greenhouse is part of an educational project in its third year at the Los Angeles State and County Arboretum. Funded by a grant from the state Air Resources Board, officials in Sacramento are keeping close tabs on the progress of the plants, receiving photographs every month of plants from both greenhouses to see what effect smog is having.
Air Is the Variable
Though its greenhouse is mainly an educational display, not a research project, the Arboretum has been able to determine when smog is detrimental to certain plants because the only variable is the air. The young plants that are put in the greenhouses are identical, all started in the propagation area in the nursery and put into the filtered air as 2-inch plants. When the roots are established (4 inches), they are separated, six plants in the filtered air, six in regular air.
There are about 32 kinds of vegetables and bedding plants and 20 different trees and shrubs in each greenhouse. They are given the same amounts of water, fertilizer and care. With the aid of the filtering system, the smog-free greenhouse has the impurities (i.e. pollution) taken out.
A monitoring system outside the greenhouses detects the ozone and nitrogen dioxide levels of the ambient air (smog-free house). There are also photographs of healthy plants and of plants affected by the smog in a display nearby.
"Some plants do better than others (in smoggy conditions)," says June Petrie, a student of ornamental horticulture who works in the greenhouses. "Like bush beans, within the first four weeks you can see a difference. Petunias, begonias and zinnias--a lot of the bedding plants people use all the time--are greatly affected by the smog."
