Suggestions for Growing Orchids Inside the Home
MANY STILL BELIEVE THAT YOU must have a greenhouse to grow orchids successfully, yet windowsill orchid growing can produce remarkable results. I have been amazed through the years at some of the orchid specimens I have seen that were grown in this manner. As with other cultural schemes for orchids, it is a good idea to strategize a bit about how you can best accomplish the task to ensure success.
By my definition, orchid culture at windows includes almost everything from a table or stand near the good light of almost any window to greenhouse windows, and even some sunrooms. The common denominator is that the sunlight comes primarily from one direction.
LOCATION It is the natural light that we are seeking to optimize when we adapt such locations into environments for growing orchids. Almost any brightly lighted location might do. Morning light from the east is always a good option, but great results can be achieved at western and southern exposures as well. I would not go out of my way to design an orchid windowsill garden at a north window, as most flowering orchids have relatively high light requirements. Nevertheless, I have known a grower who has successfully flowered orchids in her north window, so it seems nearly any location has possibilities.
In most cases, you want to situate your plants as close to the window as possible to maximize the amount of light they receive. Light levels decrease dramatically as you move away from the source.
When choosing a location in your home or apartment in which to establish an orchid sanctuary, be sure to consider trees or buildings outside the windows and how they would impact the amount of light coming through those windows in every season. Large deciduous trees, in particular, can negatively or positively impact the amount of light that can reach your plants as the seasons change. If the amount or duration of light seems too high, that can be easily remedied with sheer curtains or other types of shading.
The latitude in which you live affects the light levels coming through the window in various seasons too. As a general guide, four or more hours of bright or direct light through a window will provide many types of orchids with the amount of illumination they need to flower. Insufficient light is the most common reason that orchids fail to flower, so if you have mature plants that have not bloomed in more than a year, try moving them to a brighter spot.
SETUPS Once you have selected the location, you will want to evaluate how you can best optimize the number of plants you could grow at the window(s). In most cases, that will dictate the use of some sort of shelving or rack. Consider the cultural needs and practices that the plants will require so that you can construct or purchase a system that will make the effort as easy as possible. Watering and spraying, in particular, can be difficult in a domestic environment, so realize that the plants may need to be moved for those or other procedures.
Shelves offer the best opportunity for getting the largest number of plants possible positioned in front of the good light of a window. If the height of the window permits, I recommend looking for some sort of stand that has been designed for growing plants that suits the dimensions of the space. Most of these are designed to accommodate pebble trays or water reservoirs under the pots. While there is debate as to whether there is a real humidification benefit to be gained with the use of pebble trays, they certainly cannot hurt, and it is good to have a situation where a freshly watered pot can safely drip.
Stands that are designed for growing plants will also likely have the option of adding supplemental light with fluorescent fixtures, if desired.
Do not underestimate the value of incorporating a bit of supplemental light, even if used seasonally. The combination works well for many orchids and can transform a shady window into a floral showcase.
Be sure to maximize your window garden opportunities by using shelves that are sufficiently deep to allow you to position sun-loving orchids toward the window and those that may require less light behind them. Plants grown with such directional lighting may need to be turned with some frequency to prevent them from becoming one-sided. Yet I can tell you from experience that plants that are oriented in one direction are usually the easiest to work with when putting together orchid displays.
Humidity is often the most problematic environmental factor to adjust at a windowsill. Because most orchids seem to thrive in rather humid atmospheres that have some good air movement, humidifiers and small fans obviously offer solutions. But I have seen more than one indoor construction with so much humidification that if there had been wallpaper nearby, it would surely have slid off the walls. Indeed, mold and mildew concerns need to be kept in mind. If you really have a rainforest habitat planned for a corner in your spare bedroom, some water-proof paint or plastic tenting in the immediate area where the plants are grown could be a smart investment.
TEMPERATURE Most orchids grow best when there is a 10 to 15 F (-12 to -9 C) temperature fluctuation between the day and night temperatures. Today’s climate-controlled homes and insulated windows may make this a difficult goal to achieve. If the window receives sufficient direct light during the day, the temperature may rise near it enough to attain the ideal. A good maximum/minimum thermometer will give you the answer.
The temperature range at your windowsill growing area should guide you in selecting the orchid to cultivate there. In most of these situations you will be looking to the intermediate to cool growing types rather than those orchids that require warm growing conditions.
Temperature considerations aside, it often makes sense to cultivate those orchids at your windows that are considered to be rather “easy keepers.” There is not much point in struggling to grow those prima donnas that present challenges to orchid growers with climate-controlled green-houses. And unless you savor a challenge, it is probably a good idea to avoid growing mounted orchids in a windowsill situation as well. Mature plant size is an important consideration too. Most growers would opt for a larger number of small to medium-sized plants over a few large ones. When shelving is employed, you also have to plan for ways to handle those orchids that produce their flowers on tall spikes.
A list of suitable orchids for windowsill growers is difficult to compile primarily because it could be quite extensive. Some that first come to mind are Phalaenopsis hybrids and many of the Paphiopedilum or slipper orchids, particularly the Maudiae types and some of the traditional hybrids. Many Cattleya alliance hybrids thrive with this type of culture; look particularly for some with a more compact growth habit as well as many of the hybrids derived from Brassavola nodosa. Also, many of the popularly cultivated orchid species of various types seem to respond favorably to the seasonal variations in day length and quality of light that the windowsill environment offers. And, there are masdevallias, small-growing orchids that fit snugly on sills and put forth charming colorful flowers.
As with most all types of plant-growing situations, it is important to avoid overcrowding. You will find that crowded plants are more difficult to monitor and that insect and disease problems spread more easily among them. When space becomes a premium at your windowsill, perhaps the best solution is to look for another window.