Here is an article I wrote for the Prairie Gardener last year. I think it will help you.
Detailed Phalaenopsis Growing Instructions
By Gerry King from EverSpring Orchids
“Why would anyone spend the time on trying to coax an orchid to grow? Never mind getting it to bloom. They are so fussy and difficult to grow.” Those were my very thoughts after I spent twenty five dollars on a tiny orchid seedling only to see it wither and die a few months later! That was over ten years ago. Today I have a greenhouse full of blooming orchids and just love the challenge of getting even the most stubborn orchid to reveal its beauty with a stunning display of inflorescence.
There has always been a certain ‘mystique’ attached to the orchid. When orchids were first brought back from the New World to European plant collectors, it resulted in orchid frenzy. Many orchid hunters and collectors lost their lives looking for new and unusual orchids to satisfy the cravings of wealthy European orchid hobbyists. Of course there is the persistent story concerning the infamous searches for the elusive black orchid which really doesn’t exist, in the wild that is.
The mystique surrounding orchids could discourage one from ever trying to grow and flower this beautiful plant. Fortunately this is just a myth. Most orchids are not that difficult to grow. If one can grow African Violets, Boston Ferns, or other care free houseplants, then orchids should fit into the same environment.
The best orchid for a novice grower to try is the Phalaenopsis, otherwise known as a Phal or Moth Orchid. The flower colours vary from pure white to almost black. There is no other orchid flower in existence that carries the variety of colours and textures of the Phalaenopsis. Several varieties have amazing fragrances. An extra bonus is the incredible longevity of the flowers. The flower spike will often stay in bloom for up to six months Phalaenopsis hybrids have flowers that range in size from ¾" to nearly 5" in diameter. The mystery and beauty of a blooming orchid is very intriguing. These attributes have made phalaenopsis orchids the second most popular potted plant sold in North America.
Phalaenopsis orchids enjoy a spot near or in a bright window. An east window is the best. A west facing window is good, just watch for hot direct sun which could scorch the leaves. In the winter months or if the window is shaded by a curtain or by trees, a southern exposure is okay. You can grow Phals under fluorescent lights placed approximately 1 foot above the plant. Time your lights to simulate normal day length. Limiting light levels to 1,000 - 1,500 foot candles will provide ideal light levels.
Phalaenopsis do well in temperatures between 18° and 27° C. For optimum growing try to maintain 18° at night and between 22° and 27° during the day. Temperatures in excess of 30° can slow growth. Cool night time temperatures in autumn encourage flower spike initiation. Try adding a pinch of Epsom salts to your watering regimen at this time. This often triggers flower spikes in stubborn plants. Once the flower spike is developed, avoid wide swings in temperature as this can cause unopened buds to drop off.
Phalaenopsis benefit from moderate humidity levels. Ideal levels range between 50 and 75% relative humidity. In a heated home you will want to set your plants on a humidity tray, a shallow tray filled with gravel and water. This should help to keep the humidity near your orchid at acceptable levels. Make sure that the plants roots are NOT sitting in water.
Proper watering of Phalaenopsis is very important. Phals do not like to be dry to the point of wilting. Evenly moist is the ideal environment for Phalaenopsis roots to flourish. They should be watered thoroughly and then not again until the media is nearly, but not completely, dry.
How often you water will depend on the type of media used and its growing environment. Begin by watering your orchid approximately once per week. The weight of the pot can tell you if your plant needs to be watered. Stick your finger into the medium periodically and if it is dry, make a mental note of the weight. After a few weeks, you can adjust the watering schedule by the weight of the pot alone. Be careful not to let water settle in the crown of the plant where new leaves form and avoid spraying or accumulating water on the flowers as this will damage them.
During the active growing period of the orchid, use a fertilizer with equal proportions of N(Nitrogen)-P(Phosphorous)-K(Potash) - for example 14-14-14. In September, blossom booster fertilizer such as 10-30-20 is recommended. Apply fertilizers with every second watering at 1/4 the recommended strength. This dilute solution prevents burning of roots and leaves.
Phalaenopsis need to be re-potted about once a year. There are several reasons for re-potting your orchid. It may have outgrown its current container, the media has decomposed and is no longer aerated well enough to maintain healthy roots, or the roots may have rotted. Remove the plant from its container and let the old media fall away and carefully trim away any rotting or dead roots. Use a pot that just allows the root ball to fit in. Position the plant in the new container and pour in the new potting media, letting it settle around the roots. Orchid potting media must provide air space at the roots. Acceptable media includes a fir bark mix containing sponge rock and charcoal or other similar materials. If you use bark, ensure that you soak it at least overnight and use only the floating bark in your mix. New Zealand sphagnum moss allows the development of healthy and vigorous root systems and is the media of choice for many growers. After re-potting resume your normal watering and fertilizing schedule.
Phalaenopsis Orchids should be regularly monitored for aphids, mealy bugs, mites, scale, and slugs. Scale is one of the most common pests of Phals and can be removed with a soft cloth and soapy water or a cotton swab soaked in isopropyl alcohol. Cinnamon (a natural fungicide), Safers Soap, and Isopropyl alcohol are excellent natural remedies to keep in your orchid medicine chest. If you choose to use a commercial pest control product, be sure to carefully follow all label instructions
If your Phalaenopsis orchids are healthy, you can often urge a second flowering from each spike with a timely pruning. When the last flower on the spike fades, examine the spike for small fleshy bumps or nodes. From the base of the spike, count out 3 nodes and cut the spike just above the third node. If your plant is healthy and the season is not too late, this process will wake up one or two of the nodes and in a few short weeks, it may produce a few more fresh blooms. Keeps the flower spike facing towards the light source for more visual impact. After the flower spike dries up, cut it off about 1 inch from the base of the plant.
When purchasing an orchid, look for strong, healthy leaves, some unopened flower buds, and be sure to inspect it for insects or insect damage. It is important to purchase your orchid from a reputable orchid grower. Purchasing a Phalaenopsis from retail chains and hardware stores often means the plant has been subjected to a poor growing environment which is not a healthy start for your plant. An orchid vendor will be able to help you with your questions and be able to give you advice.
These guidelines and suggestions will make your phalaenopsis orchids bloom and grow for years to come. Phalaenopsis orchids blooming on your windowsill during a cold February day is truly one of life’s simple pleasures.