Not your average flower: Learn how to care for orchids at the Houston Orchid Society’s Annual Show & Sale this weekend

Editor’s note: Today’s blog comes to us from John Stubbing of the Houston Orchid Society.

Many people receive gift orchids purchased at local grocery stores or at “big box” stores such as Home Depot or Lowe’s. Nearly all of the orchids sold in these stores are members of the genus Phalaenopsis, known as moth orchids because of the shape of their flowers.

These very popular orchids can be recognized by their single stem and wide, flat leaves.  The flowers, usually quite large, are borne along a long spike and are typically colored white, pink, lavender or yellow.  Some come in solid hues, while others sport an array of spots, stripes, and other markings in a range of colors.

Phalaenopsis orchids make great house plants, and are good companion plants for African violets, as both have similar requirements in terms of light, temperature, humidity and amount and frequency of watering.  A word of caution: Do not put Phalaenopsis orchids in direct sunlight or in temperatures below 50 degrees.

Moth orchid flowers last for several weeks, and plants will live for many years with proper care.  A plant will typically bloom at more or less the same time every year, and can be displayed anywhere in or out of the house for your enjoyment while in flower. As the flowers begin to die, the plant should be moved back to a situation that encourages growth of the vegetative portion.

orchid 3

Moth orchids are best grown in low light, either in partial shade outdoors, or indoors in a bright window or under artificial lighting.  If Phalaenopsis are grown under artificial light, you have to be careful to watch for the development of new flower stems, and be sure to move the plant away from the lights before the stem touches the bulbs. As with African violets, fluorescent lighting is preferred over incandescent because of the heat from the latter.

The lighting arrangement I used for many years was four 4-foot-long fluorescent tubes over a 2-foot-wide shelf holding the plants. Today, with the availability of many different lighting types, you can be more creative with artificial lights. Or, you may have a bright east-facing window to provide all-natural lighting. It is often easiest to move plants for watering, then return them to the window or light stand.

An important note: Because the flower stem points towards the light as it grows, be sure not to change the plant’s orientation when returning it to the growing area or the stem will be crooked.

Moth orchids will thrive in temperatures from 60 degrees to 95 degrees. Outdoors with summer breezes or indoors with fans, they can withstand up to 100 degrees if the light isn’t too bright. If grown outdoors, they should be brought inside when night temperatures dip below 50 degrees. However, keeping them outdoors for a few weeks in the fall, when night temperatures are in the mid to upper 50s or near 60, will help initiate new flower stems. Once the flower stem has started to develop, the plant(s) can be brought indoors and the stem will continue to grow. This is safer than leaving them outdoors with the potential of damage to the plant from cold weather. Even Houston’s relatively mild winters are too cold for these tropical plants.

Conditions outdoors in Houston usually provide plenty of humidity for these plants.  Phalaenopsis plants prefer a minimum of 50 percent humidity, and their flowers will last longer with even higher humidity levels. If we get a dry spell in the summer, you can help the plants by watering more often. Indoors, humidity levels rarely get above 50 percent, and both heating and air conditioning units remove humidity from the air.  So if and when orchids are grown inside, you will need to increase the humidity in the orchids’ vicinity.

A pebble tray is an easy and inexpensive way to enhance humidity levels. Fill a shallow tray with pebbles or rocks. Add water to about half way and set the orchid pots on top of the pebbles. The water level should be below the pots (you aren’t using this arrangement to water the orchids).  Water evaporating from the pebbles’ surface adds to the humidity surrounding the plants.  You may need to add more water daily if your house is especially warm or dry. To control algal growth on the rocks and in the water, you may also want occasionally to add a bit of bleach.

The watering technique for Phalaenopsis (and most other orchids) is a little different than for most house plants. Why? Because in their natural habitat, these orchids don’t grow with their roots in the ground. They are “epiphytes” or “air plants,” and grow on tree trunks and tree limbs throughout much of tropical southeast Asia. Because of their growth habit, orchids need more air circulating around their roots than other house plants and will not survive if their roots are always wet.

Phalaenopsis are often grown and sold in tightly packed sphagnum moss. Sphagnum retains water a long time so it doesn’t dry out as fast as many other potting media.  If your orchid is growing in sphagnum, a thorough watering every other week is frequent enough.

Another popular growing medium for Phalaenopsis and other orchids is fir bark or fir bark mixes. This medium dries out much faster than sphagnum, so orchids in bark or bark mixes should be given a thorough watering about once a week.

In either case, you should water until water comes out the drainage holes in the pot.  Let the excess water drain out before putting the plant back in its growing area.  If plants are outdoors, the watering schedule should be adjusted depending on the weather. Last year was so dry that plants needed to be watered twice a week.  A few years back it rained every day in July; under such conditions, Phalaenopsis plants growing outdoors should be protected from the rain. Otherwise, their roots will become water logged and will rot, eventually killing the plant.

orchid 1

Phalaenopsis orchids need fertilizer to grow and bloom successfully. Since the plants never stop growing, they need to receive at least some food (fertilizer) year-round.  A weekly application of a dilute fertilizer solution works well. Almost any fertilizer sold for orchids will work just fine if used at quarter strength in the fall and winter, and half strength the rest of the year, each time you water. However, once a month, skip the fertilizer and use water only.

You can learn additional care tips for Phalaenopsis and other orchids at the Houston Orchid Society meetings held monthly at the Houston Garden Center.

Many of the lovely moth orchids, along with many other orchid varieties, will be on exhibit and for sale at the Houston Orchid Society Annual Show and Sale, held this year on April 20 and 21 in the Grand Hall of the Museum of Natural Science. Don’t miss this spectacular show!

Flower power: Explore the fragrant orchid at the Orchid Show & Sale on April 20-21

Editor’s note: Today’s blog comes to us from John Stubbing of the Houston Orchid Society.

Have you ever thought of growing your own orchid corsage? There are plenty of reasons to take up growing these exotic and beautiful plants as a hobby. Not only do many species have large and colorful flowers, but many orchids are also fragrant!

For example, many of the large-flowered Cattleya types (the ones typically used in corsages) have wonderful, sweet fragrances that can fill a house — so romantic. Unfortunately, the blooms lose their fragrance when cut, so the recipient of a corsage doesn’t experience the full joy of these flowers.

Some 80 years ago, in the middle half of the 20th century, these corsage flowers were cut mostly from species orchids. Collectors harvested entire orchid plants from the wild in the rainforests of Central and South America, where Cattleyas are native, and shipped them to the United States and Europe.

Cattleya percivalianaCattleya percivaliana normally blooms in December or January, so is called the Christmas Orchid

There, commercial growers would cultivate the plants until they flowered. Once the flowers were cut and sent to the florist, the plants would be discarded.

Starting in the 1930s, growers began to experiment with “man-made” hybrid orchids to use in the cut flower trade. Not only were they able to create unusual flower shapes and colors, growers also learned to regulate the flowering time of both species and hybrids to match florists’ needs.

For example, a large crop of flowers in perfect condition for sale a week after Mother’s Day or Easter would be a disaster for the grower. Manipulating the orchids’ bloom time gave growers the ability to provide cut flowers to the florist trade for all the major holidays throughout the year.

Cattleya lawrenceanaCattleya lawrenceana blooms in spring

Cattleya intermedia alba

Cattleya intermedia alba blooms March through May

For over nearly two centuries, growers have hybridized Cattleya species with other orchid genera to increase the number of flowers and widen the color range. Now we have Cattleya-type flowers ranging from blue to yellow to green to red, in addition to the traditional whites, pinks and lavenders. Many of these complex hybrids bloom several times per year, whereas most of the original large flowered corsage types bloom only once a year.

Many Cattleya orchids, whether species or hybrids, can be grown outdoors in medium-bright sun in Houston, when temperatures are above 40 degrees.  At lower temperatures, they need to be moved inside. They also can be grown indoors year-round in bright windows or under bright lights. Depending on the species make-up, the large-flowered Cattleya types will usually bloom the same month each year. The plants can be moved into the house to enjoy the flowers and then returned outside for better growth.

You can obtain additional care instructions at the Houston Orchid Society meetings held monthly at the Houston Garden Center. Also, written care sheets are available on the American Orchid Society page here.

Several of the Cattleya varieties pictured above, along with many other types of orchid, will be on exhibit and available for purchase at the Houston Orchid Society’s Annual Show and Sale. This lavish event will take place April 20 and 21 in the Grand Hall at the Museum of Natural Science.  Admission is free (except for the orchids you take home with you!)

Cattleya Nancy Off ‘Linwood’Cattleya Nancy Off ‘Linwood’ AM/AOS, with 6-inch flowers, usually blooms in the spring.

Stage-five clingers: Learn to grow epiphytes with Zac Saturday, March 24

As the horticulturist for the Cockrell Butterfly Center conservatory, I get asked a plethora of gardening questions. The most frequently asked question (other than “How’s Lois?”) has got to be “How do you get your orchids to grow on trees?”

Orchid Show at HMNS!

I explain to visitors that most orchids are epiphytic, which means that they grow on the trunk and branches of larger trees. To do this, they have developed ingenious ways to obtain water and nutrients without the need of soil. Not to be confused with parasites, epiphytes take nothing from the tree they attach themselves to. Notable examples include ferns, orchids and bromeliads, but the most familiar epiphyte to people here in the south is a wispy bromeliad by the name of Spanish moss.

There seems to be a common misconception that growing orchids is reserved for only the most experienced gardeners, but from my experience, this is not always the case. In fact, orchids seem to thrive on neglect; the most common cause of orchid death is over-watering.

epiphyte orchid

To learn more tips and tricks for epiphyte growing, join me for the HMNS adult education class How to Grow Orchids, Bromeliads and Other “Air Plants”  from 9 to 11 a.m. this Saturday the 24th in the Cockrell Butterfly Center. The class includes a behind-the-scenes tour of the Butterfly Center, followed by a hands-on class where attendees will learn how to propagate, divide, mount and fertilize their own epiphytes. And finally, everyone goes home with their very own orchid to start (or add to) their collection!

Photo Show in the Butterfly Center

A couple of years ago we installed a small “Artists’ Corner” gallery in a corner of the lower level lobby in the Butterfly Center.  It opened with an exhibition of moth paintings from art students at SFASU, followed by a collection of monarch butterfly photos from a Houston naturelover, then drawings from 6-10th grade YES Prep students.  For the next few months the corner will showcase a fabulous display of nature photographs put together by Zac Stayton, horticulturist for the Butterfly Center.

Zac is a Houston native.  He received a degree in horticulture from Sam Houston State College in 2007, and subsequently worked at Newton Nurseries here in Houston.  Then, inspired by a trip to Costa Rica, he picked up stakes and moved to Hawaii, where he spent a year working for a bromeliad grower.  Luckily for us, he returned to Texas last year so we could hire him to join our team. 

Zac is an enthusiastic and knowledgeable plantophile, and is especially fond of epiphytes such as orchids, Nepenthes pitcher plants, and of course, bromeliads.  He is also an accomplished nature photographer, and has his own website where you can see his work:  The photos on display in the gallery include a series of photos taken in Hawaii and Costa Rica, featuring plants (of course) as well as insects, other animals, and scenics.  On the other side of the display wall are photos of plants and butterflies he has taken in the Butterfly Center since starting work here last January. 

Be sure to stop by to see Zac’s photos when you next visit the Butterfly Center.  Professionals and amateurs alike will be inspired to see the beauty of the Center seen through a photographer’s eye!