We started working on the orchid room in March of 2015, and have repeatedly refined it. Initially it was just plants in trays on the windowsills, then shelves on the windowsills, then upper shelves, then skylights to add more light, then trays holding the plants and serving as humidity trays, then an RO watering system, then a drain-to-waste system for the trays, then an upper shelf, and finally grow lights. Much of the construction was dictated by the plants and how they grew and flowered. It is now getting to spring in central California, and everything seems to be growing well.
The room was initially a breakfast nook in our home, and has windows on three sides: west-facing, south-facing, and east-facing. The house is extremely well designed and constructed, so we found that the room did not have sufficient light, even in the summer months. So Skylights were installed, and eventually grow lights to supplement the natural light coming into the room.
These photos were taken on a gloomy rainy day, and the red-blue from the grow lights shines through more than on a normal sunny day.
This is a photo of the orchid room on the west side. The lower shelving is built out from the windowsill, and the homemade humidity trays sitting on the shelves will hold a six-inch pot. There is a 20-gallon RO tank, and a 10-gallon mixing tank under the shelves, together with a pump (yellow) and hose to water the plants. The top shelf is built out from the upper ledge of the window, and holds an additional humidity tray, and the LED grow lights are attached to the bottom of these shelves. The RO tank has an aquarium heater that keeps the water temperature at 78°, and an aerator, while the mixing tank contains a small pump that is used to help mix fertilizing solutions. All electrical components are controlled by WeMo switches. The PVC pipe in the corner is part of the drainage system, which currently drains into five-gallon buckets, but will eventually be routed outside. The black item on the far right is a fan that continually moves the air in the room.
This is a photo of the middle part of the room, facing south, showing the four humidity trays on the table (a round glass table that was part of the original purpose of the room), and the trays on the upper shelf. We normally place the flowing plants on the center table, and it provides a good showcase for them. There are two skylights on the ceiling, and a large pistache tree just outside the window that provides dappled shade most of the year. There is an extension to the bottom shelf, in the middle, where we have our seedlings (barely visible in this photo), with a grow light mounted on a swing-arm lamp. There are four trays on the table, four on the lower shelf, and two on the upper shelves.
This photo shows the east-facing wall of the orchid room. The plants here get early-morning sun, dappled by the leaves of a bougainvillea that is growing in a large pot outside. Under the lower shelf is my “collection” of items to maintain the room — fertilizers, bug spray, Physan, pots, stakes, supports, and the like. The PVC pipe in the corner is part of the drain-to-waste system, as is the pipe just under the middle lower shelf.
One cannot see the south-facing upper shelf in these pictures. It is high above the camera, and does get some direct sun through the skylights each day. The two trays on this shelf typically hold my Cattleyas and other high-light plants.
The amount of light coming into the room was a problem. Our house is part of a subdivision where the homes were designed to be extremely energy efficient — and they work very well, especially in the hot summers. There is a bougainvillea shading the east-facing windows, a pistache tree shading the south-facing windows, and a grape arbor shading the west-facing windows. Even with the skylights we installed, there was not enough light in the room for the plants.
So we installed LED grow lights in the room (detailed in other posts in this blog). They currently run 12 hours per day, but will be bumped up to 16 hours per day in the middle of March. As installed, they lie about 12-18 inches above the plants, and the plants seem to like it. The LED lights give off very little heat, so they do not adversely affect the temperature gradient in the room.
With the humidity trays, we can keep the humidity in the room to an average of 60% (which is much better than expected). The humidity trays contain about 3/4″ of pea gravel, and the semi-hydroponic pots drain into the gravel. Not all the water drains to the waste buckets, but some is retained in the trays. The pots sit on homemade plastic stands, slightly above the water level. If the plants are not watered for a week or so, the trays start to dry out and the humidity in the room goes down. However, we have never seen a reading less than 40%.
To try to keep everything clean and prevent disease, we run a Physan solution through the 18 trays once per month. Most orchids are planted in semi-hydro. When new plants are added, we wait for them to become acclimated to the light/temperature environment of the room and start growing some new roots before repotting them into semi-hydro pots.
The orchid room is in the southwest corner of our home, far away from the wood stove and furnace outlets. We tend to let the temperature “float” in our home, so we typically get a 10-15 degree difference in temperature in the room each day. Recorded temperatures range from 68°-82° in the heat of the summer and 55°-68° in the dead of winter. The windows are opened at night in the summer to tap the cooler temperatures at night — even though it can be hot here (greater than 100° in the summer) during the day, it does cool down into the 60s most nights.
The room holds about 70-75 plants currently, with a few open spaces.
It has been a fun project so far, and the plants seem to like it.