Southland Orchid Show 2013

Two Stanhopea were on exhibit at the show, and the owner Joe Kles of the Riverside/San Bernardino Orchid Society did a great job bringing these species to into bloom again just in time for the show this year.  I am very envious that he was able to get the timing of these to bloom just right since my Stanhopea missed blooming for the show by a week.



Stanhopea graveolens inflorescence

Stanhopea ruckeri flower

In addition to Joe, the Huntington Library, Art Collections, and Botanical Gardens also exhibited several Stanhopeinae.  It was good to see several species in bloom for the show.

Acineta mirayae
 

Acineta superba almost in bloom....very nice! 
 I can't wait until mine has inflorescences this long.

Acineta chrysantha

Acineta is a genus of orchids that is part of the Stanhopeinae, and is native from Mexico to South America.  They are large plants with big pseudobulbs that have 2-4 leaves per pseudobulb.  The inflorescences can be 11.8 to 27.5 inches (30 to 70 cm) long.  This orchid is native to moist cloud forests of Costa Rica, El Salvador, Guatemala, and Panama. It is found at elevations from 4,265 feet (1,300 m), and is a warm to cool growing orchid.  I grow this species outside with Stanhopea on the north facing side of my house in partial shade.



Acineta chrysantha inflorescence

The flowers of this species are waxy and up to 2.5 inches (6 cm) wide.  They open partially and are carried on long inflorescences to 27.5 inches (70 cm) long with up to 30 flowers.  The flowers have a base color of deep or golden yellow with reddish spots on the petals and sepals.  The labellum has large deep red spots and splotches.  The column, in contrast, is ivory white and minutely hairy at the base.  The fragrance of these orchids is rather complex, but ranges more toward a ginger or ginger beer fragrance.  I have heard of this species having a vanilla fragrance, but my variety has a more complex and intense scent.



Acineta chrysantha flower

This orchid has always bloomed for me in late summer and early fall.  The flowers last much longer than most Stanhopea, from two weeks, sometimes up to three weeks if the weather is cool.  The plant requires a cool and semi-dry rest period in early winter to induce blooms.  The first inflorescences grow out of the basket in July and take about 2-3 months to mature and open.

Stanhopea oculata (gold form)

Stanhopea oculata (gold form) inflorescence

This is a different form of Stanhopea oculata that I purchased because it has golden yellow flowers that are more intense than the other forms of the species.  The upper hypochile has a deep golden yellow color and the sepals and petals are a light to golden yellow color. This form also blooms at a later time (late summer/early fall)  than the pale cream to yellow colored form, and it only has two large eyespots on the upper hypochile rather than the four in the pale form. The eyespots and spots on the petals and sepals are a reddish brown color.

Stanhopea oculata (gold form) flower

This form also has a different fragrance that is similar to Eucalyptus, or a little like camphor.  This fragrance tends to align with the 1.8 cineole identified for most S. oculata in a study conducted by Witten and Williams in 1992.  This is a different fragrance than the other form I have that resembles chocolate mint with vanilla.  This is a great form of S. oculata that should be in everyone’s collection.

Stanhopea Fall Culture Checklist

 

As the weather begins to cool, fall is a great time to enjoy Stanhopea blooms and watch new growths emerge.  This is also a good time to repot or rebasket plants because it is still warm and many Stanhopea will continue growth through fall.  By the end of December, most warm growing Stanhopea will complete their growth cycle, and wait for spring/summer to continue growth in preparation for summer or fall bloom.

 

·         Continue watering all Stanhopea regularly and keeping them moist.  I usually water these orchids three to four times a week under normal temperature conditions.  If temperatures rise above 90°F (28°C) and humidity is low I mist and lightly water every day.  Guarding against low humidity is particularly critical growing Stanhopea outdoors in southern California due to the Santa Ana winds we often receive.  These winds are warm to hot and are devoid of humidity.  By the end of fall you can often begin to reduce watering slightly to just two times a week, or less if rainfall is plentiful.

·         Continue fertilizing all species regularly.  I often reduce the manufacturer’s recommendations to one third or one half and fertilize every week, or what is known as weakly-weekly.  Stanhopea can be rather heavy feeders when they are in active growth.

·         Fall is an excellent time to repot smaller Stanhopea or larger baskets.  I usually wait until mid to late October to rebasket because this allows the growths to increase in size and makes it less likely that you will injure them.  This is a prime time for growth for several species and rebasketing is advantageous.

·         Weed baskets to prevent ferns and other plants from taking up space in baskets.

·         In mid fall (November) I remove or roll up most of the saran shade cloth and store it until spring.  This allows the Stanhopea to receive more sunlight, albeit diffused light during the fall and winter months.  This will assist those species that grow all year and often complete their growth in the winter.

·         If you know temperatures are going to increase and humidity levels drop, you may want to consider moving a Stanhopea that is coming into bloom to a shadier more humid area, or as I often do onto my covered patio.  That way I can enjoy the flower show right from my window.  This often prevents early desiccation of flowers and they tend to last the average three to five days instead of just two.

·         Throughout fall make sure to check for growing inflorescences and ensure that their growth is unimpeded by other plants or the basket.  If need be place a plastic label underneath the inflorescence to help direct the growth out of the basket.  Some inflorescences may emerge from the baskets as late as November or December in some species.

·         Use of a methaldihide product or an organic substitute such as Sluggo is advised on a weekly basis at this time to prevent slugs from disfiguring new growth and impacting new inflorescence and bud growth.  I often use a product called “That’s It” that is a granular form and therefore leaves less residue in the growing media.  I am currently testing Sluggo as a more organic method of slug control.

·         Check for spider mites through fall as our weather is still warm and dry.  Small yellow spots on the foliage signal that these pests are active on your Stanhopea.  Spray infected areas with rosemary oil spray or an insecticidal soap to kill the pests as soon as possible to prevent them from damaging the plant further and spreading to other orchids.

·         You should also be diligent in keeping watch for fungus infections at this time on leaves.  Several fungus attack leaves when humidity is high and temperatures are warm. Black or brown spots of leaves and yellowing of leaves in odd patterns are usually the cause of fungus or bacterial infection.  Treat with a fungicide or bactericide.  I often use Physan 20 to deal with the problems and prevent further damage to the plants.

·         The warmer temperatures and reduced breezes combine to cause fungal infections such as black spot on some Stanhopea species and hybrids.  The key to reducing this problem is to make sure your Stanhopea are grown in a breeze way that gets constant air flow, or to place a fan in the growing area that produces a very slight breeze at all times.  This will prevent the fungus from settling on the leaves and disfiguring them.   This problem does not impact the health of the plant to a large degree but it does look unsightly.