Blue (Leaved) Orchids

Two recent additions to our orchid collection are miniatures with blue hued foliage, which makes them irresistible as far as I'm concerned.

Our Promenaea riograndensis is small enough to fit in the palm of my hand. It is a native of the cool humid mountain regions in Rio Grande Do Sul and Santa Catarina state in southern Brazil where it grows as an epiphyte, sometimes in association with P. stapeliodes, according to Jim & Barbara McQueen in Orchids of Brazil. The leaves are thin and pliable like many of the other moisture loving species in the subtribe Zygopetalinae. Since I don't have an elevation range for this species, I'm going to try growing it first in an intermediate greenhouse. If it looks stressed in summer I'll move it to the High Elevation House. The promenaeas are a fantastic group, well worth growing if you have the opportunity.

And then there's Dendrobium trantuanii, which has some of the most beautiful pseudobulbs I've seen. They are laterally flattened and a striking blue grey color. Even the stem sheaths are gorgeous. Denderobium trantuanii was described in 2003. It grows as an epiphyte in seasonally dry evergreen forests of northwestern Vietnam at 800 to 1,000 meters elevation. Our plants are growing in our warm greenhouse. In our greenhouse, they seem to prefer growing in small cedar baskets with a small amount of moss and chopped tree fern, rather than on a cork mount.

The flowers are about two centimeters across, waxy and glossy with a faint rosy blush. I'm looking forward to growing seedlings of these beauties produced in our lab.

Good Morning High Elevation House

Early morning in the Tropical High Elevation House --it's one of my favorite refuges. The air is cool and the sound of the waterfall is tranquil. After a hair-raising commute in Atlanta traffic, it is soothing. Like being in Ecuador again.

Fallen logs are a common sight if you are hiking in an Ecuadorean forest. They sometimes carry a treasure load of epiphytic plants--orchids, bromeliads, begonias, gesners--plants that you normally see only through binoculars. To achieve the fallen-log effect in the HEH, we selected a 7' driftwood branch, mounted epiphytic orchids on it, and placed it at an angle in front of the waterfall. The base rests on the stream bank and the tip leans toward the face of the waterfall. After a year, the orchids are established and starting to flower. This month four species of Maxillaria are flowering simultaneously.

Maxillaria lehmannii, with the regal white flower grows as an epiphyte in wet montane cloud forests in western Ecuador and Peru. To its left, is the adorable Maxillaria coccinea, with coral flowers. It grows in Colombia, Venezuela, Brazil and the Caribbean at 500 to 1000 meters. It doesn't seem to mind the cool temperatures in the HEH.

Closer to the base is Maxillaria c.f splendens, with nodding elongated flowers. M. splendens comes from Peru, where it grows as an epiphyte at 2000 meters elevation.

And finally, my mystery Maxillaria, source unknown, nicely embedded in the moss carpet that is overtaking our branch.

Don't forget to visit the Tropical High Elevation House when you are visiting the Fuqua Orchid Center!

At last, Dendrobium anosmum

And, finally, the big payoff: our one hundred Dendrobium anosmum are flowering. Spectacularly.

Remember these guys? We purchased them last summer out of bloom for cheap knowing that they make an easy and awesome spring display when treated correctly. Right after the holidays we moved them to our cool greenhouse for a six week cool (53º nights) dry (water every 10 days) rest. By the end of March they had shed most of their leaves and the bare canes had big fat buds at every node.

Here they are on April 1, a little scruffy with a few yellow leaves still clinging to the canes, but not a big deal to clean up for display.

Very handsome. The flowers and sepals are covered with soft downy hairs.

And they smell terrific. Intensely sweet with maybe a hint of grape. Catch them on display in the Orchid Display House!

Dendrobium aphyllum

Dendrobium aphyllum in late April and early May in the Orchid Display House. 

Dendrobium aphyllum is amazing. The medium-sized plant pictured above produced more than one hundred flowers this spring. Almost every node on the gracefully arching pseudobulbs produced a pair of lavender flowers, each with a densely fuzzy white lip. For me, it's the plush velvet lip, not simply the floral production, that makes this orchid irresistible. 

Dendrobium aphyllum grows in India, Myanmar, Thailand and south China at 200 to 1800 m in seasonally dry tropical forests. The plant produces new leafy shoots in the spring that eventually become long slender pseudobulbs. The pseudobulbs shed their leaves after about a year. (Aphyllum means leafless.) Buds form in winter on the mature pseudobulbs.

In cultivation D. aphyllum (and similar species like D. anosmum) will thrive on a slab of tree fern, cedar or cork, or in a hanging basket to accommodate the pendant pseudobulbs. Our plant is mounted on a slatted cedar slab. A small slatted basket creates a healthy environment for roots, but can become quirkily lopsided if the plant insists on directing all of its new growth to one side.

Our plant gets the spa treatment in summer in a warm moist greenhouse. In November we move it to a cooler (53º nights) brighter greenhouse and back off the watering somewhat until January when the buds are visible. Aside from a thorough watering every ten days or so, it needs no maintenance at all during its winter rest. A terrific plant!

Nothing Says Spring Like Dendrobium

 Dendrobium lindleyi

For two incandescent months from mid March to mid May the Callista Dendrobium species illuminate the Fuqua Orchid Center. It's as though they want to join the burst of spring bulbs during Atlanta Blooms.

These beautiful and tremendously rewarding dendrobiums deserve greater attention from commercial growers and hobbyists.

Dendrobium lindleyi

What is a Callista Dendrobium?
The genus Dendrobium is so large that it has been divided into sections, based on general similarity. Dendrobium section Callista* contains 10-14 of the most admired species in the genus.

Dendrobium thyrsiflorum 

Callista dendrobiums grow in mainland southeast Asia at intermediate to high elevations in areas with a pronounced dry season. During the winter dry season Callista Dendrobium species that grow in deciduous forests experience cooler temperatures and brighter light.

Dendrobium thyrsiflorum, an early spring Narcissus wannabe

In cultivation Callista Dendrobium species need a moist tropical summer followed by a dry rest (often a cooler dry rest) in winter in order to initiate buds. Our plants receive 53º night temperatures and are watered less frequently from Thanksgiving through New Year's. This change in temperature and watering routine requires very little effort on our part.

Dendrobium chrysotoxum 

It seems insane to be so lavishly rewarded for so little effort! It's certainly not hard to figure out a way to water less frequently. If you manage the temperature drop you should definitely consider growing the Callista dendrobiums.

*Syn. Densiflora

Is There a Blue Orchid?

Dendrobium victoriae-reginae flowering this week in the Fuqua Orchid Center

There are a couple contenders for the 'Blue Orchid' crown. One of them is the royal blue Dendrobium victorieae-reginae.

This beautiful orchid with pendant pseudobulbs and waxy blue-violet flowers is native to the Philippines where it grows at moderately high elevations (1300 to 2600 m) in wet mossy forests.

Our plants are permanent residents of the Tropical High Elevation House where they grow at eye level on a driftwood tree. The forests in which this species grows never experiences a regular dry season, so our cultivated plants are watered throughout the year.

The name victoriae-reginae denotes that the plant was named in honor of Queen Victoria whose Golden Jubilee was celebrated around the time of its discovery in 1897.

The other species that that comes up in any discussion of blue orchids is Vanda coerulea (coerulea= sky blue) which has imparted its blue violet pigment to many richly colored hybrids.

Both of these orchids are extremely popular. What do you think--does either orchid deserve the name 'Blue Orchid'?

Embreea rodigasiana

Embreea rodigasiana flowering this week in the Fuqua Orchid Center

In the back up greenhouses at the Atlanta Botanical Garden is a bumper crop of seedling Embreea orchids that have just reached flowering size. They are making their debut this month in the Orchid Display House. Embreeas are considered to be rare and difficult in cultivation, so we are delighted to be able to show them to you.

Embreea is a striking orchid that resembles the closely related genus Stanhopea. It shares with Stanhopea the pollination syndrome associated with male Euglossine bees,--large tropical bees that collect fragrance. The waxy flowers are huge (about four inches) and their eucalyptus-like fragrance is highly attractive to Euglossines. The flower points downward and the column and lip together form a chute to guide the bee past the pollen masses located at the tip of the column.

Embreea produces a single-flowered spike, rather than the massive multiple flowered spike of Stanhopea. The horns on the lip have a very distinctive hatchet shape.

Since Embreea rodigasiana comes from an especially wet area of western Colombia--the Choco region--we water our plants more frequently than we do our stanhopeas. Embreeas absolutely need a humid greenhouse in order to flourish outside of the warm tropics. Our plants do well in a mixture of New Zealand sphagnum and chopped tree fern fiber. A wire or net basket is needed in order to accommodate the pendant spike which often grows downward through the medium.

Don't miss these! You can find them in the Orchid Display House this month in baskets hanging below the beams of the cedar pergola.

Openings: Week of April 30

Cyrtochilum serratum in the Tropical High Elevation House

Whenever one of our ravishing cyrtochilums flowers I want to call the newspaper. They are just so exceptional in every way--exceptionally beautiful, exceptionally rare in cultivation, and unfortunately, exceptionally difficult to grow outside of the cloud forest. I feel flattered when one of ours flowers.

All of the Cyrtochilum species are native to the misty upland forests of the Andes where their extraordinarily long rhizomes scramble up trees and shrubs. But it's the flower spike, or inflorescence, that will make you stop for a second look. It's a graceful twining strand that winds its way up, around and among surrounding trees like rainforest tinsel, with as many as 100 flowers per strand.  Cyrtochilum serratum is  native to Ecuador and Colombia. If you guessed that Cyrtochilum is closely related to Oncidium, the Dancing Lady Orchid, you are correct.

Medinilla magnifica

Magnifica indeed. Without a doubt, the most commented upon plant in the Orchid Center right now is Medinilla magnifica, one of the all time great plants for conservatories. Not an orchid. It is a large shrub in the mostly tropical and frequently ornamental Melastomataceae. I have noticed M. magnifica for sale in Atlanta garden centers this month. It is not hardy in Atlanta. Melastomes, even large ones like Medinilla magnifica, are easily rooted by cuttings.
We have quite a nice collection of melastomes at ABG, and if you like M. magnifica you will love our recently installed Medinilla miniata, similar in size and aspect, but with fiery red flowers. Melastomes come in all sizes, but they are easy to recognize. The leaves are opposite with veins that lie parallel to one another. The flowers have a peculiar feature: the stamens are elbow-shaped.

Pleurothallis cyanea on a tree in the High Elevation House

If you visit the Tropical High Elevation House this week you will see a burst of flowers on some of my favorite clamshell orchids, Pleurothallis cyanea, P. gigantea and P. teaguei,  P. marthae and ever-blooming P. titan. I love the thick coriaceous leaves on Pleurothallis cyanea.

Cavendishia grandifolia

Cavendishia grandifolia is one of the most impressive plants in the Tropical High Elevation House and certainly our largest shrub. It's astonishing to realize that this plant, with its fifteen foot pendant branches is an epiphyte. It's a mighty plant that can support one of these sprawling monsters. Each of the thick platter-like leaves is ten to twelve inches long. You can get a closer look at those gorgeous tubular flowers here. We have two grandifolias: the one pictured above cascades over the waterfall; the other is draped over the arch of the tepui.

Lots of orchids in flower this week! Please stop by for a visit.

The Orchid Tapestry

The Conservatory Lobby features an Orchid Tapestry 

Orchid Daze 2012, Hanging Gardens was designed by Tres Fromme of StudioOutside. Tres' design for the entrance makes brilliant use of the soaring space inside the Conservatory Lobby. The orchid tapestry measures 12' from floor to ceiling. As seen from above its curving outline is broadly S-shaped as it traces a path between two opposing beds. The tapestry forms a vertical arch above the pathway in several places, allowing visitors to walk beneath it.

The Pansy Orchid (Miltoniopsis) is a terrific subject for this display. Miltoniopsis flowers are as large as those of Phalaenopsis and nearly as long lasting. The arching spikes are shorter than those of Phalaenopsis, but the plant typically produces 5 or more spikes of beautifully presented flowers. Miltoniopsis is much more tolerant of cool temperatures than Phalaenopsis, and so pairs well with Cymbidium, Dendrobium nobile, Masdevallia and other cool growing orchids that wither in the company of warm-growing Phals. 

And they smell delicious. In fact the fragrance in the Conservatory Lobby is overwhelming--in a sweetly floral way.

Oncidium Twinkle (we used two color forms: 'Red Fantasy' & 'Yellow Fantasy') makes a perfect pairing with Miltoniopsis hybrids, in texture, color and fragrance. The delicate texture of the flowers looks wonderful alongside the bolder flowers of the Pansy Orchid. I have always wanted to use Oncidium Twinkle in a display and finally had an opportunity this year.

Orchid Daze 2012, Hanging Gardens runs through Sunday April 15.

Shiny Rings & Orchid Things

It was pure pleasure selecting the orchids for the giant shimmering rings suspended above the Formal Bed in the Orchid Display House. When you are working with a palette of cool colors the choice of orchid varieties expands enormously.

Doritaenopsis Long Pride 'Sparks' HCC/AOS

Phalaenopsis are an obvious choice for any orchid display, with their graceful arching habit, large flowers and amazing longevity. The Doritaenopsis in our display are an intergeneric cross between Phalaenopsis and Doritis, two orchid genera so closely related as to be considered synonymous by some taxonomists. Doritaenopsis Long Pride 'Sparks' HCC/AOS is one of the most beautiful harlequin varieties that we have ever featured in our display--certainly worthy of the spotlight.

Beallara Tahoma Glacier 'Sugar Sweet'

Beallara is the name given to the offspring resulting from a sequence of crosses between the genera Brassia, Cochlioda, Miltonia and Odontoglossum. Thus, Beallara is an intergeneric hybrid, as is the Doritaenopsis above, only more complex in its genetic background.

I love the über-feminine look of these beallaras. They wear their frothy Odontoglossum lineage on their sleeves. Tahoma Glacier is pure white overlaid with rosy markings and a favorite of mine in a display where white is needed. 'Howard's Dream' is one of only a few Oncidium intergenerics with a large flower that reads purple, not red violet.

Beallara Marfitch 'Howard's Dream'

One unfortunate characteristic of some Beallara cultivars is their extremely weak flower spikes. The spike will often break under the weight of its full complement of mature flowers unless it is staked along its entire length. We learned this the hard way, of course, after an entire bed of 'Howard's Dream' collapsed prematurely during Orchid Daze 2007. So, beware. If not staked 'Howard's Dream' becomes Howard's Nightmare.

Beallara Big Shot 'Kitty Kat'

Finally, the diminutive Big Shot 'Kitty Kat,' which we just used to replace the 'Howard's Dream.' Most of the Oncidium intergenerics last about eight weeks in flower under our conditions. Since Orchid Daze lasts ten weeks we do a switchout at week eight. 'Kitty Kat' is a new variety for us and an unexpected delight.

Sunday is the last day to see Orchid Daze 2012! We are open every night until seven pm.

Our Kennel of Bulldog Paphs

"Bulldog" Paphiopedilum hybrids displayed on the Cube in the Orchid Atrium

Probably the most popular orchids on the hanging Cube in the Orchid Atrium are the Asian Slipper Orchids, the paphiopedilums, or "Paphs." These particular Paphiopedilum hybrids are colloquially known as "bulldog Paphs" on account of their broad-faced flowers and drooping petals. Among the most famous of the bulldogs is Paphiopedilum Winston Churchill. You can read more about this famous hybrid here.

The bulldog Paphs make outstanding display orchids. Their enormous shiny flowers are mesmerizing when viewed at eye level and they are extraordinarily long lasting (for Paphs, anyway)--eight weeks if you can keep the daytime temperatures at or below 72º.

Paphiopedilum species in nature are usually, but not always, terrestrial. They often grow as understory plants, or wedged into crevices in rocky limestone or granite outcrops. Adapted to an environment where there is a fairly dependable reservoir of moisture surrounding their roots, Paphs are not as drought tolerant as their epiphytic relatives, like Cattleya and Laelia, which often possess thickened leaves to resist moisture loss and pseudobulbs to store water.

Thus, in cultivation, Paphiopedilum orchids enjoy more subdued light, a more moisture retentive medium, and more frequent watering than Cattleya orchids.  They do well under lights or on an east facing windowsill. On a windowsill they will need a few hours of mild morning sun in order to flower. Most growers pot their Paphs in a mixture of fine grade bark, charcoal and perlite, often with some additional peat or milled sphagnum.

You won't want to miss these extraordinary orchids. And don't forget your camera!

The Garden is now open every night until 7 pm. The Orchid Daze display runs through April 15.

Dramatis personae: the orchids

The hanging Cube in the Orchid Atrium

Now that you've seen the Orchid Daze 2012 display as a whole you might like to meet some of the individuals in leading roles--the orchids, of course.

Rows of Dendrobium nobile occupy one side of the Cube

Dendrobium nobile hybrids are among the most rewarding orchid hybrids to grow and display. A well grown Dendrobium nobile hybrid will put any of the ubiquitous Dendrobium phalaenopsis hybrids completely into the shade. The flowers are larger, more colorful, more abundant. They make a gorgeous bouquet-like presentation. And they last a good 8 to 9 weeks in perfect condition before the flowers show any sign of decline. Once you have mastered these you may never want to grow another Den. phal hybrid.

Dendrobium Red Emperor 'Prince'

Dendrobium nobile hybrids are easy to grow. You just need to know one thing about them, and it's that one thing that sets them apart culturally from their Den. phal cousins. In a word, it's seasonality. In nature the growing conditions that they experience in summer are dramatically different from the conditions that they need in winter in order to set buds. In short: warm moist summers and cool dry very bright winters. These are the conditions you have to mimic in order to grow Dendrobium nobiles well.

In the summer we grow our Dendrobium nobile orchids in a 50% shade greenhouse at 80% humidity. We fertilize every two weeks with Cal Mag 15-5-15 from April through August and then stop the high nitrate fertilizer in order to harden off the new canes, which are staked for support. At Thanksgiving we move the nobiles (and the Dens in section Callista) into a nearly full sun greenhouse that drops to 53º at night, watering about every two weeks. This year, admittedly, a freaky warm year when all growth has been accelerated, they flowered in March.

The renowned growers and breeders of Dendrobium nobile hybrids at Yamamoto Dendrobiums have produced a terrific cheat sheet for growers. Don't forget to check out their gallery, which ought to get your pulse going!

Orchid Daze 2012, Hanging Gardens

Orchid Daze 2012, Hanging Gardens still looks magnificent in week 9.

In fact the entire Orchid Center & Conservatory are at their spring best, full of flowers (and flower photographers) and bursting with color.

The hanging tapestry of Pansy Orchids (Miltoniopsis) in the Conservatory Lobby is one of the most popular elements of the Orchid Daze display. Pansy Orchids produce a wonderful fragrance--far better than any synthetic perfume. They are one of my favorite orchids for big displays, with bold, long lasting flowers, good presentation, fragrance--and they look great with fine textured orchids like Oncidium Twinkle.

The  modernist Cube in the Orchid Atrium allows visitors to appreciate the orchids at eye level. It has become a favorite stopping place for photographers.

In the Orchid Display House three shimmering orchid rings hover above the Formal Bed.The metallic silver of the rings looks terrific with the cool colors of the Beallara and Phalaenopsis hybrids.

Orchid Daze 2012, Hanging Gardens runs through April 15. Be sure not to miss it!