The benches are of Wolmanized lumber and quarter inch hardware cloth. Corrugated fiberglass runs directly under the bench tops so plants can be housed under bench without runoff. Surprisingly, a good share of the collection winters under bench. For example, thirty full-size phalaenopsis sit on ten foot long, ten inch high movable shelves placed under the center bench from about November through April. In April, the shelves are placed on top of the North wall bench and the phals begin to acclimate to light. In June, I run an inside white fabric shadecloth over the phal section which is removed in September. Phals are usually repotted in September. Come October, they are again under bench. Optimal? No. But it makes it possible to enjoy 700+ plants!