Dendrobium Phalaenopsis (Den-DROH-be-um fal-en-NOP-siss)
These upright growing plants are native to South East Asia and Australia. They produce multitudes of colorful flowers from stems emerging out of the top of each newly developed cane. In some instances these plants re-flower from previously flowered canes as well as from the newly developed canes to deliver an abundant amount of flowers. In essence, plants with multiple canes can produce flowers several times a year and remain in flower nearly all year! On average, blooming longevity on each stem of flowers can last of up to 4 months. While in flower it is best to keep the plant out of any direct sunlight to prolong the blooming longevity. When the flowers have expired they should be removed at the point of emergence from the plant.
To ensure good growth along with profuse flowering, the Dendrobium Phalaenopsis requires bright light throughout the year. They prefer some direct sun and do best when receiving the light source from above rather than from the side of the plant. This helps keep the plant growing in an upright fashion. While growing inside your home (October through May) a south or west exposure is recommended. In some cases an unobstructed bright east exposure is adequate too.
Dendrobium Phalaenopsis does best when grown outdoors during the months of June through September. Hung from a tree or the overhang of your house, placed in a sunny screened porch, tucked in the bushes where they can receive some dappled sunlight, or direct morning sun is ideal. Dendrobium Phalaenopsis can benefit from higher intensities of light as the day length decreases towards fall and into winter, and vice-versa for the spring and summer. Try to provide as much light as possible for your plant throughout the year without causing sun burn on the leaves. Once your Dendrobium Phalaenopsis is in the flowering stage it is best to shade it from any direct sun to prolong the life of the blooms.
One of the cultural elements that make the Dendrobium Phalaenopsis such a popular plant is that they love to grow in the same temperature range that we also live with in our homes. On average these plants perform best when grown between 58 degrees at night to 85 degrees day. Of course we do not heat our homes to 85 degrees during the winter day so do not read this as they absolutely require that much daytime warmth to do well however, the warmer the daytime temperature the faster the plant will grow and subsequently the more flowering sequences you will experience.
Proper indoor watering requires allowing the bark mix to become dry throughout the entire pot. This can be somewhat difficult to diagnose for the beginner grower so here are some tips. Factors such as how root bound your pot is, how much light the plant is receiving, and what size pot it is in, will all play a role on how fast it dries out. Typically while growing indoors a good thorough watering once a week should be sufficient. Keep in mind that the smaller the pot is the faster it will dry out and the larger the pot is the longer it will take to dry out. Over watering is the worse thing to do for a Dendrobium Phalaenopsis.
When watering, water the bark thoroughly until water runs freely from the bottom of the pot. Always remove your pot from any decorative container to allow for proper drainage. Never allow your pot to stand in any water as this will cause root rot. Never use softened water on any of your orchids.
While growing your Dendrobium Phalaenopsis outdoors your watering technique will change very little however, you will need to monitor the needs of your plant according to the weather. If you notice any shriveling of the cane this is usually a symptom of dehydration and your signal to water a bit more often. While outdoors the natural rain on the plant is highly beneficial.
Dendrobium Phalaenopsis are fairly active growing plants, and therefore fertilizer is essential for good growth and flowering. We recommend applying a 20-20-20 or similar balanced type fertilizer once every 2 to 3 weeks throughout the entire year. A safe dilution ratio is one level teaspoon of fertilizer mixed in one gallon of water. Do not over-fertilize as this will cause permanent root damage.
Like many orchids the Dendrobium Phalaenopsis enjoys a moderately humid climate of 50% or greater. When growing these plants indoors it is recommended to increase humidity around the plant. This is simply achieved by placing your plants on a humidity tray, misting them adequately in the morning, or grouping your plants all together in one area
We recommend repotting Dendrobium Phalaenopsis every two to three years. If you are not experienced or comfortable doing this yourself we offer the repotting service at our greenhouse for a small fee. Your recently purchased Dendrobium Phalaenopsis may be ready for a repotting job as soon as it has finished flowering. Inquire with us as to when your individual plant was last repotted. Good indicators for a repot candidate are: when the rhizome and roots of the plant have protruded over the edge of the pot; when the potting medium starts to break down and drain poorly; or when the plant is completely root bound in the pot. It is best to repot just as new roots sprout from the rhizome which is typically after flowering has completed or during the spring and summer months as the plant becomes actively growing again.
Dendrobium Phalaenopsis may be divided if the plant has enough pseudobulbs (commonly called canes) to safely do so. A division should consist of four canes minimum, all still bearing healthy leaves. This will ensure that the plant will have enough strength for future growth. Larger divisions of 6-10 canes are preferred, which in turn will make for a specimen plant the next blooming season. If your plant is not dividable at this time simply repot it into a slightly larger pot.
To make a proper division, begin by examining your plant for a natural dividing line between the pseudobulbs that will give you equal size halves, both having at least one new growth if possible. Using a large stiff knife, make a cut through the rhizome and root mass to make the division. Try to keep the root mass intact as much as possible as this will prevent transplant shock. Some leaf-less canes can be removed and discarded at this time, but it is important to keep your minimum number of canes to ensure a healthy division.
A note about orchid viruses: most commonly the transmission of orchid viruses is caused by using the same cutting tool on multiple plants. The most effective method to reduce virus transmission from plant to plant is to briefly flame sterilize all your cutting tools between use on each plant. A simple Butane torch or a gas stove are handy items for this purpose. This practice should be implemented when repotting as well as when cutting off expired flowering stems.
Once your division is made, select a new pot in the appropriate size to allow for another two years of growing. Unfortunately there is not a set rule for choosing the proper pot size, but generally you will need to increase the pot size by one to two inches. Do not use too large of a pot because these plants like to be somewhat crowded, even after repotting. The Dendrobium Phalaenopsis prefers to be potted into clay pots for the benefit of the porosity offered by the clay as well as the stability from the weight.
Place your Dendrobium Phalaenopsis plant into your selected pot and add our moistened fir bark orchid potting mix around the roots. Position the plant in the pot so the junction of the plant and roots is buried one half inch below the potting mixture. Pack the potting mixture firmly with a blunt tool to ensure the plant is secure in the pot. Wait about one week and then water thoroughly.
Happy growing, from Orchids Garden Centre & Nursery!