Friday, 18 September 2015 16:45

Phragmipedium (frag-meh-pee-dee-um) Culture (commonly called “Phrag”)

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The Phragmipedium is commonly known as the South American Slipper orchid and is frequently called Phrag (frag) for short. These are terrestrial growing orchids native to areas of Mexico, Central and South America. These orchids are incredibly easy to culture in the home and often have a blooming period of six months or more. A distinct feature about Phrags is that they produce their blooms sequentially, one after another, after another. Each bloom remains in flower for approximately two weeks while another bud develops. When it is time for the flower to expire, it falls from the stem while still looking nearly perfect. Do not despair, this is common. Once the flowering stem is completely finished producing flowers it will start to turn brown and begin to die back. It then can be removed by cutting it off at the point where it had emerged from the leaf. During the period when the plant was producing flowers, another growth was developing and that is where the next flowering stem will emerge. It is not uncommon to see an adult Phrag produce blooms continually for many months.


In our Wisconsin climate the Phragmipedium prefers to be grown in a bright area where they will receive some direct sun. A bright east or west window where the plant will receive some direct sun on the leaves is recommended. A south exposure is also suitable, but be sure the plant receives no more than two to three hours of direct sun daily.

Some tips for growing in a south exposure: During the winter months the south exposure in our Wisconsin latitude is very bright due to the sun being so low in the horizon. During this period the direct sun in a south window can damage the leaves of a Phragmipedium, therefore it is recommended to position the plant where it will receive no more than two to three hours of direct south sun daily. During the summer months the south exposure has the opposite effect where the angle of the sun is very high and no direct light is received. It is then that you will need to move the plant to an east or west exposure to ensure proper light levels or supplement light with an artificial plant light.

Moving the plant to a shaded outdoor location is also an option, being sure to protect the plant from any hot direct sun. Whichever exposure you choose for your Phragmipedium, try to provide as much light as possible throughout the year without causing sun burn on the leaves. If your Phragmipedium is growing fine but not producing flowers, it is a sign that you need to increase the light levels.

Phragmipedium can also be grown and flowered successfully under artificial plant lights such as fluorescent lights, high pressure sodium or metal halide. Some artificial plant lights produce enough heat to burn the leaves if positioned too close to the plant. When using any artificial plant light source be sure to position the plants under the lights in accordance to the needs of the plants. If in question, consult Orchids Garden Centre & Nursery for more detailed information.


One great aspect of raising the Phragmipedium is that they are tolerant of a wide range of temperatures. They also do not need the cooler night temperatures to set their flowering spikes as many other orchids do require. When growing these either indoors or outdoors, a range of 50 degrees at night to 80 degrees daytime is preferred. A good rule of thumb is, if you are comfortable so is the plant. Keep in mind that consistent cool temperatures will slow the rate of growth and subsequently slow the frequency of the blooming periods.


One of the easiest elements about growing Phrags is their watering needs. They prefer to be kept consistently moist, therefore we recommend placing the pot in a small saucer of water. Use a saucer that is only slightly larger than the diameter of the bottom of the pot and no more than one inch deep. The idea is to make it possible for the plant to consume that amount of water in less than a week. This avoids the water from becoming stagnant which can lead to some undesirable issues. When the saucer is completely dry it is time to water again. Slowly pour the water in at the top of the pot allowing the saucer to become full again.

If you choose to not use the saucer method for watering your Phragmipedium then it is recommended to water the plant 2 to 3 times a week, or whatever it takes to keep the potting medium consistently moist. Water thoroughly until water runs freely from the bottom of the pot. Never use softened water on any of your orchids.

These plants will tolerate dryness periodically, but if grown consistently dry they will become less vigorous and be reluctant to produce flowering spikes.


Phragmipediums are known for their rapid and vigorous growth along with an extended blooming period. Therefore, a regular fertilizing schedule is needed to maintain their health and vigor. We recommend applying a 20-20-20 or similar balanced fertilizer once every 2 to 3 weeks. A safe dilution ratio for these plants is one level teaspoon mixed in one gallon of water. Do not over-fertilize as this will cause permanent root damage.

To properly apply the fertilizer solution, slowly pour it in the top of the pot allowing the saucer to become full of the fertilizer solution. If you are not using the saucer method then simply pour the fertilizer mixture copiously over the potting medium until it flows freely from the bottom of the pot.


Like many orchids, the Phragmipedium enjoys a moderately humid climate of 50% or greater. Therefore while growing these plants indoors it is recommended to increase humidity around the plant. This can be achieved simply by placing your plants on a humidity tray, misting them adequately in the morning, or grouping your plants all together in one area. While growing outdoors this is not an issue since we generally have adequate humidity in our Wisconsin summer climate.


We recommend repotting Phragmipediums every year, to every year and a half. 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 Phragmipedium 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 plant has grown itself up and out of the pot; the roots are becoming abundant at the surface; or when the pot is completely root bound.

To properly repot your Phragmipedium simply remove it from the pot and let the existing potting mix fall away from the roots. Once you have all the mix away from the roots you will be able to distinguish the healthy roots from the not-so-healthy, rotted roots. If your Phragmipedium is completely root bound then no potting mix will fall away, no root trimming will be needed and your potting process will continue from there.

In some cases Phragmipediums can be divided providing the plant has enough growths to do so. This is a somewhat technical process and is best addressed by a commercial grower or someone who has prior Phragmipedium dividing experience. If you were to tackle dividing your Phragmipedium yourself, the rule of thumb is to have at least six mature growths to start with. A safe division is a three to four growth piece. Dividing is done by cutting the rhizome and root zone in a place that will allow you to have the minimum three to four growth piece.

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 Phragmipedium is properly prepared it is time to select the appropriate size pot. Selecting the proper size pot is the next most important aspect in repotting a Phragmipedium. Select a pot that is only large enough to accommodate the roots comfortably. If you need to force the root mass into the pot, then it is not large enough and you may need a size or two larger. The rule of thumb is not to use any pot larger than what comfortably accommodates the roots. It is always recommended to use a new pot and be sure it has adequate drain holes in the bottom.

Next, set your plant into the pot and begin adding our moistened fir bark orchid potting mix. Work the mix in between the roots by gently shaking or tamping the pot to allow the mix to fill in between the root crevasses. Position the plant so the junction of the roots to the plant is just below the surface of the mix. This will allow the new roots to immediately enter the new mix.

Once the pot is nearly full of the mix, begin to pack the mix somewhat firmly to properly anchor the plant into the pot. Sometimes a blunt tool is needed to properly firm up the mix. Repotting is now completed. Wait several days and then water the plant thoroughly.

It is recommended that you do not use the saucer method for watering after the Phragmipedium has been freshly repotted. Allow the plant several months time to produce new roots into the potting medium for before using the saucer method again. This will avoid root rot and get your freshly repotted Phragmipedium off to a healthy start.


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