Moth orchids (Phalaeonopsis spp.) have become very popular over the past few years. Because of the ease and speed of tissue culture propagation, these once rare and treasured plants have become available to the masses. They’re readily found at flower shops, grocery stores and garden centers nearly year-round.
Moth orchids make wonderful holiday gifts. Their delicate blooms are born on arched flowering stems, and each flower stalk can last for months. The flowers come in a broad range of colors, including purple, pink and cream, but the most common is pure white. Some growers use dye to change the color of the flowers to an unnatural shade of purple, green, blue or bright pink, but I find the natural shades of the moth orchid are far more beautiful than artificially colored ones.
Regardless of the flower color, when the last flower fades, many moth orchids get tossed in the garbage or on the compost heap because the owner thinks it’s difficult to get them to rebloom. However, with the right kind of care and attention, they can produce secondary flower stalks, and they can be brought to bloom repeatedly for many years.
There’s no doubt that getting an orchid to rebloom can be tricky business, but the moth orchid is among the easiest. Because of the way moth orchid flowers develop, encouraging secondary flower spikes is fairly easy.
Each flowering stalk (called a spike), contains many separate flower buds. The lower flowers open first, and the stalk tip continues to grow and produce more flowers over a long period of time. To prolong the flowering time, keep the blooming plant in a cool, bright room out of direct sunlight.
Once the last flower drops off the flower spike, follow the tip of the stem back to the stump of the lower-most flower. Then continue to follow the stem down to the second inverted V-shaped node beneath that stump. The nodes are a lighter shade of green than the flowering stem, and they may also be slightly raised. Cut the old flower stalk off just above this node using a pair of clean, sharp pruners. Within a few weeks, a new flowering spike should develop out of this node (see photograph). It doesn’t always happen, but you’ll know in a month or so if it does.
After this secondary spike finishes blooming a few months later, cut the entire flowering stalk off, all the way down to the leaves.
Continue to water the plant weekly by placing it in a sink full of tepid water for an hour and then letting it drain. When the danger of frost has passed in the spring, move your moth orchid outdoors into a shady area, and continue to water it regularly.
When June arrives, start fertilizing it every two weeks with a liquid organic fertilizer. I use fish emulsion or liquid kelp.
When nighttime temperatures begin to drop in autumn, move the plant back indoors. Choose a bright window or put the plant under grow lights and continue to water it regularly, but stop fertilizing.
If you’ve done a good job caring for your plant and fertilizing it regularly throughout the growing season, your orchid should develop new flower spikes in early winter. Repot the plant into a slightly larger pot every three or four years, using an orchid-specific growing mix.