Stanhopea impressa

This species is native to the western foothills of the Andes Mountains and is found in moist montane forests in Colombia and Ecuador.  The orchid grows at elevations between 1,640 to 6,000 feet (500 to 2,000 m).  The 4 inch (10.2 cm) wide flowers are cream colored to white and have a few sparse reddish spots along the petals and more on the sepals, hypochile and column. The center portion of the flower is infused with an intense yellow-gold color. The fragrance of the flowers is similar to basil and is slightly herb-like, but with an undertone of moth balls.

Stanhopea impressa inflorescence

This is the first to bloom of three clones that I have, so there may be more variation in the species than at first glance. Stanhopea impressa is a mid summer bloomer and tends to bloom after a related species S. embreei which has a fantastic fragrance.  Stanhopea impressa is easy to care for here in southern California and requires cool to intermediate temperatures to perform well.  The horticultural requirements are similar to other Stanhopea species such as S. tigrina, though the species tends to perform better with more shade and water.

Stanhopea gibbosa

This orchid is native to wet and humid forests of Costa Rica, Nicaragua, and Panama and grows best in intermediate temperature conditions .  It grows from 1,640 to 4,920 feet in elevation (500 to 1,500 m).  The 4.5 to 5 inch (11.4 to 12.7 cm) flowers are yellow to cream colored and have several reddish spots on the sepals, petals, and hypochile.  The flowers have a nice scent of Eucalyptus, menthol, and pine mixed together.  This species is often confused with Stanhopea costaricensis, but this species appears to have a more prominent and consistent form with two bulges at the back of the hypochile which is different than S. costaricensis. 

This Stanhopea appreciates shade and an abundance of humidity and water.  It tends to perform poorly without these cultural requirements and is shy to bloom.  I tend to water it every day during the summer, and even that seems to be insufficient.  I think it would prefer to be constantly moist and humid at all times.

Stanhopea gibbosa inflorescence

Stanhopea gibbosa single flower

Stanhopea oculata

This species is native to Mexico and Central America (perhaps south to Brazil) from elevations of 3,280-9,842 feet (1000 to 3000 m). It is found in foothill and mountain forests and it grows in intermediate to cool conditions.  This is one of the Stanhopea that can easily grow outdoors in coastal southern California and requires shade and high humidity to perform well. The flowers are moderate sized 4.3-4.5 inches (10.8-11.4 cm) wide, and there are many forms that are buff colored to bright yellow.  There is a considerable amount of variation in color and quantity of spots on the petals and sepals with most having a torus shaped (like the letter O) red to purple colored spots.   Several forms have a plethora of intense red to purple spots on the upper hypochile and the epichile. 

Stanhopea oculata inflorescence

The best known characters used to identify this species is the narrow hypochile that is bent at a 90 degree angle, and several dark red eye spots along the hypochile and base of the petals.  The eye spots are what provide us with the epithet “oculata” meaning eyes in Latin.  The most common form of S. oculata sold in southern California has two eye spots on each side of the hypochile and also two eye spots on each petal.  The inflorescences are up to 25 cm long with 5 to 9 flowers per inflorescence.

Stanhopea oculata flower exhibiting
two eye spots at the base of each petal.

Along with the ease of growth and flowering, and the variable flower color, this species is also well known for its fragrance.  This fragrance has been described as vanilla mixed with mint and a hint of cocoa.  If that fragrance sounds too good to be true, it isn’t, it actually comes close to a chocolate peppermint patty candy scent.  The fragrance rivals that of S. tigrina and can easily fill a room, or be detected twenty feet away in my garden.  This is definitely a species that every Stanhopea grower should have at least one form of!

Stanhopea oculata inflorescence

Stanhopea Temperature Requirements

Stanhopea grow well in Tropical and Subtropical climates and many orchid enthusiasts would place them in temperature classifications of intermediate to warm growing.  There are some exceptions and several species tolerate intermediate to cool conditions as well.  Those species that are tolerant of cooler conditions are better suited for growing outside here in southern California due to our cool nights during the winter.  However, most Stanhopea benefit from growing outdoors during the summer and many species are more floriferous when grown outdoors.

There are several temperature classifications for orchids that could apply to the three classes I have described above, however for the uses of growing Stanhopea, I have modified some of these classifications.  The warm classification is primarily 60.0-65.0°F (15.5-18.3°C) average temperatures during winter nights, the intermediate classification is 50.0-60.0°F (10.0-15.5°C) average temperatures during winter nights, and the cool classification is 40.0-50.0°F (4.4-10.0°C) average  temperatures during winter nights.  These classifications are only a general guide for these orchids and some species grow quite comfortably in more than one classification.  Some species such as S. oculata can be found growing well in all three classifications.  This temperature tolerance may be due to the broad distribution of this species and the ability of it to adapt to a wide range of temperature regimes.  Stanhopea oculata successfully grows outdoors in the U.S.in such differing climates as Hawaii, Florida, southern California, and Puerto Rico.  For a complete list of recognized species and temperature requirements see the Stanhopea Temperature Requirements Table 

Here in San Diego my Stanhopeas have been subjected to temperatures as low as 31.0°F (-0.6°C) and as high as 105.0°F (40.6°C).  I expected some damage to the leaves of the Stanhopea plants with the lowest temperature just below freezing, but no long term damage was evident.  Even a few weeks after the light freeze, there did not appear to be any damage to the plants.  One factor that could have assisted the orchids is that I grow many of them under the canopy of trees, and these canopies may have protected them from frost.  The warmest temperatures of 105.0°F (40.6°C) are often accompanied by low humidity and drying winds, so I usually mist or even water the plants daily for the few days in the year when there is excess heat.  Just to clarify, the extreme temperatures listed above were only for brief periods of time, and Stanhopea cannot tolerate extremes in heat or cold for extended periods of time.

The average temperatures in my growing area for winter are 46.0°F (7.8°C) at night and 65.0°F (18.3°C) during the day.  The average summer temperatures in my growing area are a bit higher than San Diego's listed temperatures due to the fact that I live a few miles inland from the ocean.   The average summer temperatures are 65.0°F (18.3°C) at night and 84.5°F (29.2°C) during the day in my  growing area.  These relatively mild conditions are appropriate for growing several of the intermediate to cool tolerant species such as S. oculata, S. tigrina, and S. wardii.  These three species are what I call the “Big Three” of Stanhopea culture because they are easy to grow and relatively easy to obtain from orchid nurseries in my region.  The warm growing species such as the hornless Stanhopeas, S. annulata, S. cirrhata, and S. pulla and the Candida group (S. candida, S. grandiflora, and S. reichenbachiana) require warm temperatures during the winter [nothing below 60.0°F (15.6°C), if only briefly].  These warmer growing species also seem less tolerant of low humidity conditions and tend to exhibit leaf browning as humidity is reduced.

Stanhopea tigrina var. nigroviolacea 'Predator' on left, Stanhopea tigrina var. nigroviolacea center and left

When choosing a Stanhopea to grow, try to ensure that you can provide the best growing conditions that match the natural growing conditions of the species.  For example S. tigrina grows in the mountains west and north of Veracruz at elevations from 1,969 to 5,577 feet (600-1,700 m).  We can learn a great deal about the temperature requirements of a plant by reviewing the climate of the area that it is native to.  This is not a new concept and other growers have eloquently described this in detail.  I have chosen the city of Jalapa, Mexico to demonstrate this concept.  Jalapa is located at an elevation of 4,682 ft (1,427 m) near the upper range of S. tigrina distribution.  Stanhopeas are not native to the city proper but are native to the region surrounding the city, so this provides us with a general idea of what temperatures S. tigrina is subject to (see Table 1 below).  This table provides us with some key pieces of information for growing S. tigrina. First, winter low temperatures range between 52.2-57.6°F (11.2-14.2°C). Second, the two following months in April and May are the warmest months for average high temperatures for the year, and that there is a 19.8-22.3°F (10.5-12.4°C) difference between night and day temperatures known as the diurnal temperature change during the winter months prior to this.  This shift in temperatures appears to have an impact on some Stanhopea species’ ability to increase flower production.  Several growers have had difficulty in blooming Stanhopea species in a more controlled environment (e.g., a greenhouse), but after moving the plants outdoors in spring and summer the plants bloomed more regularly and with more inflorescences. For more information on S. tigrina habitats see Edouard Faria’s blog Stanhopea Passion - Stanhopea tigrina.

Tabel 1. Temperature data for Jalapa, Mexico
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year Avg.
Average high °F	71.4	73.0	79.9	80.4	82.9	78.4	77.4	78.3	78.3	77.0	74.7	72.7	77.0
Average high° C	21.9	22.8	26.6	26.9	28.3	25.8	25.2	25.7	25.7	25.0	23.7	22.6	25.0
Average low °F	52.5	52.2	57.6	59.9	63.1	61.0	60.6	61.2	61.5	59.4	57.2	54.0	58.3
Average low °C	11.4	11.2	14.2	15.5	17.3	16.1	15.9	16.2	16.4	15.2	14.0	12.2	14.6

Data collected from WorldClimates.com

I grow all of my intermediate to cool growing Stanhopea outdoors throughout the year.  The success I have growing and blooming these species is in large part due to the temperature range of the region I live in, and similarities to the temperatures that species such as S. tigrina experience in nature (see Tables 1 & 2). For example, in my area of San Diego our average winter low temperatures are a little lower than Jalapa at 48.9-52.8°F (9.4-11.6°C), but within the range of temperature variation within the distribution of S. tigrina.  These average winter low temperatures appear to be comfortable for this species and they often continue to grow through January in my area.  This species also performs very well growing outdoors in Santa Barbara, California where the average winter low temperatures are colder 40.3-45.2°F (4.6-7.3°C) (see Table 3).  The winter temperatures in Santa Barbara are cooler than the temperatures in Jalapa, but this adjustment to lower temperatures probably represents temperature tolerance and variability in the species. 

Table 2. Temperature data for San Diego, California
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year Avg.
Average high °F	65.9	66.5	66.3	68.4	69.1	71.6	76.2	77.8	77.1	74.6	69.9	66.1	70.8
Average high °C	18.8	19.2	19.1	20.2	20.6	21.9	24.5	25.4	25.1	23.6	21.1	18.9	21.6
Average low °F	48.9	50.7	52.8	55.6	59.1	61.9	65.7	67.3	65.6	60.9	53.9	48.8	57.6
Average low °C	9.4	10.4	11.6	13.1	15.1	16.6	18.7	19.6	18.7	16.1	12.2	9.3	14.2

Data collected from climate-zone.com

Table 3. Temperature data for Santa Barbara, California
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year Avg.
Average high °F	63.7	64.6	65.3	67.4	68.6	71.2	73.9	75.4	75.2	73.1	68.5	64.4	69.3
Average high °C	17.6	18.1	18.5	19.7	20.3	21.7	23.3	24.1	24.0	22.8	20.3	18.0	20.7
Average low °F	40.3	43.2	45.2	47.1	50.1	53.6	56.9	58.2	56.5	51.5	44.7	40.1	49.0
Average low °C	4.6	6.2	7.3	8.4	10.1	12.0	13.8	14.6	13.6	10.8	7.1	4.5	9.4

Data collected from climate-zone.com

The month of April is the first month of inflorescence initiation of S. tigrina in my collection and this coincides with a 13.5-17.0°F (7.5-9.4°C) diurnal temperature change in the winter months prior to initiation.  While these diurnal temperature changes are not as dramatic as those in Jalapa, these appear to be enough to encourage the S. trigrina to be consistent in flower production each year and more floriferous.  This is not to suggest that Stanhopeas cannot be grown in greenhouses and bloom successfully.  Several growers have successfully grown and flowered Stanhopeas in warm conditions.  However, it has been my experience that many Stanhopea including S. tigrina grow better, and are more floriferous growing outside here in southern California  rather than in a greenhouse.  I know of several growers who had difficulties blooming S. tigrina until they moved the plants outdoors.  Barney Greer in his book The Astonishing Stanhopeas provides several examples of species (e.g., S. florida, S. maculosa,  and S. platyceras) that he could not bloom in his greenhouse, but when moved outdoors they began to flower.  Other species of Stanhopea that he grew outdoors as a matter of preference (e.g., S. deltoidea, S. martiana, S. ospinae, S. pozoi, S. tigrina, and S. wardii) and others that grow best in a greenhouse with cool [50.0°F (10.0°C)] night conditions (e.g., S. embreei, S. guttulata, S. hernandezii, S. insignis, S. panamensis, S. posadae, S. ruckeri, S. stevensonii).

If you are having difficulties in blooming some of these Stanhopea you may want to try growing them outdoors if you have the proper climate, or move them outdoors for the summer.  Outdoor diurnal temperature changes between [15.0-20.0°F (8.3-11.1°C)] should provide the proper conditions to initiate flowering.  If you don’t have the option of growing Stanhopeas outdoors, try lowering the temperature of the greenhouse during the night in winter and summer a few degrees, down to 55.0°F (12.7°C) or even 50.0°F (10.0°C), if your other plants can tolerate that treatment, you should have an increased chance in flowering your Stanhopea.  Linda Kraus in her article in the American Orchid Society Bulletin “The Culture of Stanhopeas – Confession of a Requited Love” stresses that she grew her Stanhopeas cool with night temperatures of 52.0°F (11.1°C) even in the summer.  Thus she kept her Stanhopeas in a cool greenhouse condition and they bloomed well.

Printed References:
Greer, B. 1998.  The Astonishing Stanhopeas The Upside-down Orchids. Self Published.

Kraus, L. 1984. The culture of Stanhopeas – “Confessions of a Requited Lover”. AOS Bulletin 53(4): 358-366.

Stanhopea nigripes

Stanhopea nigripes young inflorescence

This Stanhopea is native to Peru and grows from elevations of 2,625-6,235 feet (800-1900 m).  It grows in mountain forests that have high humidity and environments that are often moist to wet.  This is one of the Stanhopeas in my collection that dislikes dry growing media and prefers to be moist at all times. This species especially responds well to extra water in the summer and during dry windy days.  It prefers shade and it grows on the north east side of my house where it receives no direct sun, even in the summer months.  This orchid is listed as an intermediate to cool grower, so I have it growing near the protection of the house and covered eaves.

The fragrance of this orchid is a rather heady mixture of eucalyptus and camphor mixed with vanilla.  This is an intense fragrance for this orchid and it can be detected a few feet away from the flowers.  It is a very pleasing fragrance especially around the end of the year holidays.

Stanhopea nigripes flower

The inflorescences are short 4.0-6.0 in. (10-15 cm) long, therefore  this species does best growing in smaller and shallower baskets.  The flowers are 3.9-4.3 in. (10-11 cm) wide and are beige to a light cream in color with the upper hypochile and base of the petals enfused with yellow.  This form was a bit difficult to identify because it superficially resembled S. florida in color and the flowers are slightly larger than typical, but the bend in the hypochile is greater than 90 degrees, therefore more similar to  S. nigripes.  I had originally purchased this species as S. haselowiana, but the epichile does not have the shallow bend of that species.  To ensure proper identification I sent these photos to Rudolf Jenny, and he has determined that this is S. nigripes.  Thank you Mr. Jenny!

Stanhopea nigripes hypochile

The species is a short to medium sized Stanhopea with pseudobulbs 1.2-1.6 in. (3.0-4.0 cm) wide and leaves 7.9-12.6 in. (20-32 cm) long.

Coryhopea Red Martian

 

Coryhopea Red Martian inflorescence with three flowers

 

This orchid is an intergeneric cross between Stanhopea martiana and Coryanthes macrantha var. aureum.  There is a lot of hybrid vigor to the plant and it grows large rather quickly.  The flowers don’t open fully and are best viewed from below. They are quite spectacular to look at and have been described as alien looking.  The fragrance of the flowers is rather similar to cherry cough syrup or cherry cola.  This is a very agreeable fragrance indeed. There are two leaves per pseudobulb. The leaves are lanceolate in shape 18 to 19 inches (45.7 to 48.3 cm) long, and 3.0 to 4.25 inches (7.6 to 10.8 cm) wide.

 



Coryhopea Red Martian flower
photographed from below

The flowers are 3.5 to 4.5 inches (8.9- 11.4 cm) wide and a deep red color with many mahogany to red spots on the sepals, petals, and hypochile.  The sepals and petals are cream to white at the tips with red spots.  The upper hypochile is orange-red to deep red in color and the mesochile and horns are yellow with mahogany spots/streaks.  The epichile is bright yellow on the lower portion with deep red spots/streaks, turning solid red on the upper portion..



Coryhopea Red Martian with
human heart shaped buds

Unopened buds are a joy to watch grow and develop.  Once they mature they almost appear to be oddly shaped human hearts.  This makes the opening of the flowers full of anticipation and almost unnerving! I grow this orchid warm and bring it indoors during the winter given that one of the parents of the cross is a warm growing Coryanthes.  It spends the rest of the year growing outdoors on the north side of my house.

 

 

Stanhopea wardii

 

Stanhopea wardii var. citrina inflorescence with five flowers

This species is native to Nicaragua, Costa Rica, Panama, Colombia, and Venezuela.  It grows in warm to cool cloud forests from 2600 – 5300 feet (800-1600 meters) in elevation.  It is one of the easier species of Stanhopea to grow outside here in southern California, and can take early morning sun and dappled shade the rest of the day.  This form is S. wardii var. citrina and has green/yellow flowers when they first open, almost chartreus in color.  The flowers later fade to a more burnt yellow or golden yellow color.  The standard form is a more subdued yellow color.  Both forms have a black eye spot on the upper hypochile that is a deep golden yellow color.  The fragrance of this Stanhopea is rather intense lemon/citrus at first.  After the flowers have been open for a few hours the fragrance lessens to a tart lime fragrance similar to crushed lime leaves.  It is a very pleasant and clean fragrance.  This seems to be consistent with the fragrance study done that includes limonene in some clones at 1.7%.; however, I have not detected the 1.8 cineole of 1-33% that would give it a Eucalyptus or camphor-like fragrance in this form.

 

Stanhopea wardii var. citrina close up

The flower is 2.8 to 3.1 inches (7.0 to 8 cm) wide but there are usually several flowers (7-10) on a given inflorescence.   The inflorescences can be quite long, up to 9 inches (22.9 cm) in length in many S. wardii forms.  Because the inflorescences are so long, this species can make a very nice specimen placed in a large basket that enables the inflorescences to grow out and down.  The leaves of this orchid are a thick and leathery, green with a slight blue-gray tint to them, and are 9 to 16 inches  (22.9 to 40.6 cm) long and 2.8 to 3.8 inches (7.1 to 9.6 cm)  wide.  This orchid is one of the more easily grown species of Stanhopea and are often readily available in the orchid nursery trade.  For me, S. wardii has been a reliable bloomer every year and easily produces several inflorescences.  These attributes make this Stanhopea a good candidate to grow for a beginning grower.



Stanhopea wardii var.
citrina bud


The buds that are close to opening have a fantastic flourescent chartreus color, and the reddish brown spotts on the sepals can be seen before the flower opens!



Stanhopea tigrina var. nigroviolacea 'Predator'

S. tigrina var. nigroviolacea 'Predator" with two new flowers opening.

Awesome is an adjective that I like to use to describe this orchid.  It is one of my favorite varieties of Stanhopea that I usually place with S. tigrina var. nigroviolacea.  This orchid has some of the darkest and most intense oxblood, to almost black color on the petals and sepals.  As the grex name implies it is named after a favored cinematic alien invader that hunted humans.  The comparison of the photos here will allow you to make up your own mind…..they do resemble each other to me!

S. tigrina var. nigroviolacea 'Predator' with
four inflorescences open.

This plant is one of my older specimens and I re-basketed it last year.  Since I had purchased it over 10 years ago, it consistently provided me 2 inflorescences each year until last year when it only had one flower.  This year it has rewarded me with nine inflorescences and four have opened all at once.  This orchid has a strong fragrance that is very intense in the cool of the morning until about 11:00 a.m.  A large plant such as this one can produce several inflorescences, and the fragrance of the flowers can be so intense that it can be detected 20 feet away from the plant.  Some people find the fragrance too strong, and almost intoxicating!  The fragrance of these orchids is often described as chocolate and vanilla.  The major component of the fragrance of this orchid and several other Stanhopeas is phenylethyl acetate which can often provide a floral, fruity, or Liqueur-like fragrance.

 

Stanhope tigrina is a sturdy plant for southern California and is not only one of the showiest species in the genus, but is rather easy to grow.  It can often take early morning sun along the coast without burning and dappled shade the rest of the day.  Average fertilizer and water throughout the year are all it demands.  This is one species that can easily be placed in a large basket because the inflorescences can reach over 8 inches in length (20 cm) and can easily grow out of larger baskets.  These orchids produce the largest flowers in the genus and can approach 6 inches (15 cm) in width.  The leaves are tough and leathery 10.0 -12.5 inches (25.4-31.8) cm long and 3.3-4.5 inches (8.3-11.4) cm wide.

Here is another of my attempts at timelaps photography of Stanhopeas.  I was only able to get the last half of these two flowers opening.  It is difficult to get to the flowers before they open in the morning, so I had better be up at 4:00 a.m. for the next chance. 

Stanhopea shuttleworthii



Stanhopea shuttleworthii buds glowing
in the morning sun, 2 days from opening.

Waiting and watching Stanhopea inflorescences mature and come into bloom is part of the fun of growing this genus.  It is especially satisfying to witness the first flowering of a plant for the year.  This orchid surprised me by producing five inflorescences this year and the first one was way ahead of the rest.  This orchid was in bloom for a good 3 weeks, though with only one or two inflorescences at a time open.  Once Stanhopeas grow large enough, they are able to provide you with weeks of bloom even thought the individual flowers may last 3-5 days.

Stanhopea shuttleworthii with 5 inflorescences

This Stanhopea is native to Colombia and is found in foothills around 3000 feet (1000 m) in elevation. This species is listed as a warm grower, but seems to do just fine outside here in southern California.  It is provided a little extra shelter of a roof overhang in winter, so the plant is grown a bit warmer than some of my other species. I have this growing on the north-east side of the house and it only gets approximately 1 hour of direct sun in the summer.  The leaves are 15 - 17 inches (38.1 - 43.2 cm) long, 3.4 - 3.8 inches (8.6 - 9.5 cm) wide, and narrowly lanceolate in shape. The flowers are 5.6 inches (14.3 cm) wide.



Stanhopea shuttleworthii hypochile detail

This form has deep golden yellow sepals and petals with several reddish-brown large spots. The petals have large deep red eye spots at the base. The hypochile is primarily yellow with dark blood red eyespots on the side with what appears to be blood red smears on the inside of the hypochile.  The horns and epichile are primarily white with small red spots on the inside of the horns and top of the epichile.  There are forms that have lighter yellow sepals and petals with lighter reddish spots.

The fragrance of S. shuttleworthii is difficult to describe.  Some people say it smells like mothballs, others say it smells like an expensive perfume.  The fragrance shifts a bit, first smelling similar to vanilla when the flowers first open, later a combination of sweet mothballs and a light lemon scent.  After the flower has been open for a few hours, the fragrance reminds me of lemon meringue.  Most people find the fragrance rather pleasing and a good combination.

 

 

One of my first attempts to capture Stanhopeas flowering. The difficulty is making sure you are up early enough to have the equipment running in order to capture all the movements of the buds opening ;-)