The Orchid Display House is a 5200 sq. ft. landscaped greenhouse. The front half, landscaped in a formal style, is surmounted by a cedar pergola. Many of the orchids are displayed on a rotational basis, either in baskets hung from the pergola, or in pots. The back portion is landscaped in a more naturalistic style, with orchids permanently installed on trees or in the ground. Of all of our greenhouses, the Display house supports the widest diversity of orchids, encompassing those which grow at 4,000 ft. elevation and less. Daytime temperatures reach a maximum of 85° in summer and a minimum of 60° in winter. The humidity ranges from 65-85%. Many microclimates in the Display House are associated with epiphyte trees and the varying amounts of shade and moisture that they provide both on the ground and internally. The light and moisture available within the vertical strata of an epiphyte tree has to be carefully considered when we install epiphytic orchids. We use both living and dead epiphyte trees.
In the display greenhouses a variety of rocks are used as a substrate for different lithophytic and epiphytic orchids. Lava, granite,
limestone, hardened limestone and Mexican pot rock are very different in the degree to which they absorb water and release mineral ions. Orchids of all types and other plants grow readily in the crevices of porous lava boulders. Phragmipediuim roots attach to granite boulders alongside the waterfall and stream in the High Elevation House. Angracoids are growing robustly on soft Florida limestone in the Malagasy bed. Lithophytic Mexican orchids like Rhyncholaelia have been somewhat shy about putting their roots down on Mexican Pot Rock, which is extremely hard and dense. We recently renovated our Paphiopedilum outcrop, replacing the granite that was initially installed with crystalline limestone. We anticipate that lowland calcareous species like philippinense, stonei, and rothschildianum will enjoy growing in the crevices of these rocks. Florida
The medium used for terrestrial plants in the
beds consists of equal parts fine fir bark, fine charcoal and Permatill, an expanded slate product similar in particle size to the bark and charcoal. Permatill is manufactured in Orchid Center and is used to break up clay soils and to discourage pine voles in the SE. (It also goes by the name of “Vole Bloc.”) It is hard, sterile and inert. The mixture is long-lived. Its cation exchange capacity is quite low so we rely on slow release fertilizers for our larger non-orchidaceous foliage plants. Terrestrial orchids like Sobralia, Phaius, Stenorrhynchus thrive in it. Quite a few epiphytic orchids grow well in the ground in this mix. North Carolina
We have tried a number of native trees as non-living epiphyte hosts, including Sassafras, Kalmia, Rhododendron and Cedrus. Cedar is the most durable (5 years+) of the three trees and orchid roots attach readily to the sinewy textured surface. To provide additional surfaces for epiphytic orchids we have created faux trees by cladding vertical greenhouse supports in tubular cork. Orchids are mounted with fishing line or 18 gauge wire. Moss is used sparingly as it breaks down quickly with repeated watering in our climate, retains salts and becomes a haven for slugs. We prefer to mount orchids either bare-root or with a pad of coarse tree fern fiber.