Orchids can be found in many colors


If you grew up on the mainland in the 1950s, you might have formed a limited idea of orchids.

In that era, in a temperate climate, orchids were a large lavender flower that seemed more animal than vegetable. These exotic specimens appeared in corsages on the wrists of young women or as boutonnieres on older women’s or bridegroom’s chests. These rare specimens were used to celebrate special or formal occasions and were always expensive.

Today in Hawaii, we see orchids everywhere. They are grown in outdoor pots, the crotches of trees or displayed indoors while in bloom. They decorate tropical drinks, are made into lei and used in fancy hairdos. Though they are special flowers, orchids are not rare or exotic, and they come in a plethora of sizes, shapes and colors.

Considered the largest plant family in the world, Orchidaceae includes more than 700 genera and some 20,000 species. The lavender cattleya we knew in the ’50s is but one. Vanda, dendrobium, phalaenopsis, cymbidium and vanilla are a few of the other genera we may recognize and enjoy, but we are still only scratching the surface of the orchid family.

Even cattleya orchids come in a variety of colors including white, green, pink, yellow, orange, red and purple. This genera and related hybrids also come in a wide range of sizes and shapes. Cattleya orchids’ popularity makes them a standard example for orchid culture and care, even though each species has particular cultural needs that should be addressed.

Cattleya, like most cultivated orchids, are epiphytes, or air plants, meaning they grow best in or on a loose medium that allows their roots to have contact with moist air. The roots are covered with a spongy velamen which retains water. Most also have large water-storing pseudobulbs. These organs hold sufficient water to allow the roots to dry out a bit between waterings.

A bright environment out of direct midday sun with temperatures between a nighttime low of 55 degrees and a daytime high of 85 is ideal for growing orchids. With increased shade, and lots of humid air circulation, they can tolerate temperatures as high as 95 degrees.

Most orchids are not salt-, wind- or drought-tolerant and need a humid environment to thrive. They can, however, suffer from overwatering. Allow a few days for roots to dry before watering. Air circulation is important to prevent bacterial or fungal diseases that thrive in humid environments.

Orchids can be encouraged to grow and bloom by regular additions of a low-concentrate fertilizer. Plants should be re-potted when the growing medium breaks down and no longer drains well or when the plant outgrows its container. When dividing your orchid, be sure each new plant has at least three pseudobulbs to help get it started.

Though orchids have long held a reputation for being delicate, most species are actually very hardy and can be grown in Kona. An opportunity to learn more about orchids, view many orchid varieties and purchase plants from knowledgeable growers is scheduled July 28.

The theme for the 31st annual Kona Daifukuji Orchid Club Show is “A Rainbow of Orchids.” Attendees will enjoy a display of hundreds of orchids in a variety of colors.

The show opens at the Daifukuji Soto Mission Hall in Honolo at 8 a.m. Arrive early to be greeted with an orchid boutonniere, while supplies last. The displays, as well as complimentary refreshments, will be available until closing at 2 p.m. Don’t miss the 10 a.m. performance of the Daifukuji Mission’s Taiko Drumming Group as they fill the Mission Hall with their percussive energy.

This event is part of the club’s mission to promote fellowship among orchid lovers and teach others about orchid culture. Club members will staff a booth where attendees can have their questions answered or get expert advice on orchid growing. Information for new members will also be available.

The club meets the second Wednesday of the month at Mission Hall, at mile marker 114, near Teshima’s restaurant. Admission is free. For more information, visit kdoc.us, facebook.com/orchidsinparadise or call 328-8501.

Diana Duff is a local organic farmer as well as a plant adviser and consultant.

Tropical gardening helpline

Sandy asks: What can I do to keep spider mites from attacking my hibiscus hedge. I live on the dry side of Waimea and unless I routinely spray with a miticide, the mites continue to appear. In my limited research, it was suggested to use lady bugs, but I have no idea if they can be purchased on the Big Island.

Answer: We do not have access to lady bugs for biological pest control. Though they may be naturally present, their numbers may not be adequate to handle your infestation. Predatory mites also live here in Hawaii and may provide help. Go to ctahr.hawaii.edu/organic/downloads/Predatory%20Mites%20FINAL.pdf to learn about them.

Other control methods exist, though none is guaranteed to rid your plants of spider mites completely. Spider mites like dry and dusty conditions. Spraying your plants — including the undersides of leaves — regularly with water can discourage them. Applying neem oil and safer soap will kill mites on contact and have a minimal effect on their predators. Resistance to various chemicals has been reported in a number of spider mite species; insecticides may lose their effectiveness if the mites develop a resistance.

UH-CTAHR offers a publication on mites at ctahr.hawaii.edu/oc/freepubs/pdf/MP-2.pdf to find the downloadable pdf file.

Email questions to konamg@ctahr.hawaii.edu for answers by Certified Master Gardeners.

Some questions will be chosen for inclusion in this column.