Blueberry Surprise

Cavendishia tarapotana var. gilgiana in the Fuqua Orchid Center

The most beautiful of our tropical blueberries, Cavendishia tarapotana var. gilgiana*, surprised me this month with a burst of flowers. The last time our plant flowered was in July of 2011 so I had begun to think of it as a long day plant--i.e., a species requiring short nights in order to set buds. Maybe not. Regardless, the species is an absolute stunner and well worth a look if you are visiting the Tropical High Elevation House in the Fuqua Orchid Center.

Blueberries and Rhododendrons belong to the same family, the Ericaceae. Like many of the tropical blueberries, Cavendishia tarapotana var. gilgiana is an epiphytic shrub, and a gigantic one--each of our two plants measures about 6' from tip to tip. It is native to Colombia and Ecuador. Tropical blueberries produce fruits that are rich in antioxidants, but not so rich in flavor. Not bad, just bland. Some enterprising hybridizer may take them in hand one day, but I think they are wonderful just as they are.

Tropical blueberries are easily propagated by cuttings of the current year's growth 5-6" long, using either Rootone or a 10% solution of Dip 'n Grow. Our cuttings are rooted under fog in a cutting mix of 3 parts perlite to one part peatmoss. They root in about eight weeks. We grow our plants in an mix that we use for our tropical epiphytes. It consists of milled sphagnum, fine fir bark, charcoal and tree fern fiber. A mix of equal parts fine fir bark, charcoal and peatmoss works equally well.

*syn. Cavendishia gilgiana

There's Something About Slippers

Phragmipedium Don Wimber

The pollen masses (pollinia) are hidden behind the shield-shaped staminode in the center of the flower.

Phragmipedium Cape Sunset flowering at the Fuqua Orchid Center. The yellow pollinia are just barely visible over the top of the staminode.

How do you explain the appeal of slipper orchids? What is it about slippers that makes them irresistible?

I think it's the pouch, or toe cap, of the slipper that is the lure. Very few of our visitors can resist the urge to get closer and peer inside. What's inside that pouch? What's it for?

It's a trap, actually, for the insect that pollinates the slipper orchid. For an insect what's inside that pouch is a convoluted and probably exasperating journey in search of an exit. Once underneath the tightly inrolled lip the insect is forced behind the shield-shaped staminode where it collects or leaves behind the pollinia, and finally escapes. The pouch is a trap to ensure fertilization. No insectivory is involved.

If you love slippers you won't want to miss our spring Orchid Daze 2013 display opening February 9! Our display will feature slippers of all sizes, shapes and colors.

A Bucket Orchid Opens

Coryanthes alborosea opening at the Atlanta Botanical Garden.

Coryanthes alborosea one half hour after opening.

The right-hand flower of Coryanthes alborosea. Note the liquid already accumulating in the bucket.

If you arrive at the Fuqua Orchid Center greenhouses early in the morning you can sometimes catch a Bucket Orchid (Coryanthes) bud in the act of opening. The bud looks like an enormous wrinkled chrysalis. It usually takes a couple of hours to fully open. First, the bud splits lengthwise along its seam, then the petals and sepals reflex backward to reveal the amazing lip. Coryanthes flowers only last about three days.

Wednesday morning I photographed a pair of Coryanthes alborosea flowers as they opened. The half-opened sepals framed the lip like angel wings.

Love the furry cap.

Click here to find out how a Coryanthes flower works.

More Coryanthes in Flower

Coryanthes macrantha flowering at the Atlanta Botanical Garden

More of our extraordinary bucket orchids are flowering. Coryanthes macrantha (above) is one of the parents of the hybrid featured in my last post. You can see what the other parent looks like here. Although Coryanthes are, in my experience, among the more difficult orchids to grow, Coryanthes macrantha has always been a consistently strong grower for us.

I'm also looking forward to seeing the first flowers on the seedling offspring of Coryanthes macrantha var. alba this year.

Coryanthes, the Bucket Orchid

Coryanthes macrantha flowering at the Atlanta Botanical Garden. The genus Coryanthes is called the Bucket Orchid.

How it works. The  Coryanthes "bucket" (facing right) is part of the flower's lip, a highly modified petal. The other two petals and three sepals (left) are reflexed backwards like wings. Coryanthes flowers produce fragrance attractive to male Euglossine bees. After brushing the fragrance from the lip, the bee falls into the bucket.

The back door. After immersion in the liquid-filled bucket a bee must force his way out through a small opening at the rear where a pollen bundle is deposited on his back. 

Autumn brings a flush of new root and shoot growth to our (insert your own adjective) Bucket Orchids. A few, like Coryanthes macrantha, are far enough along in their development to produce flowers. The flower pictured above measures about four inches from top to bottom. A Coryanthes flower would make anyone stop for a second look.

Tiny Fireworks

Masdevallia herradurae flowering in the Fuqua Orchid Center

There are a few orchids that produce culinary fragrances --vanilla, lemon, chocolate, coconut, white cake icing, wintergreen, cilantro, to name a few--fragrances that I usually associate with the kitchen rather than the greenhouse. Masdevallia herradurae is the only orchid in our collection that produces a fragrance like cinnamon. Red Hots, to be precise.

When tiny Masdevallia herradurae appeared among a new shipment of plants last year I was instantly charmed by the handful of exquisite flowers that were visible. At the time I didn't bother to investigate the fragrance.

Matt Richards then installed our Masdevallia herradurae plants on a Sassafras branch in the Tropical High Elevation House. Since then I have patiently watched as they produced their first tentative roots, a new flush of leaves and finally, buds. I have been eagerly anticipating their first flowering.

At last the flowers are open.  Each tiny plant has produced between 50 and 75 flowers. The branch has hundreds of tiny flowers. Masdevallia herradurae is a magnificent bloomer.

What was totally unexpected about this burst of tiny fireworks was the strong fragrance of cinnamon. No other Masdevallia in our collection is strongly fragrant of anything (at least to me), let alone something tasty. I have fallen in love with this orchid all over again.

Masdevallia herradurae is easy to grow. It grows over a fairly wide elevational range in Colombia and Ecuador: 500 to 2100 meters. I suspect it would adapt well to intermediate temperatures in a humid environment. If you're growing Masdevallias under lights you may want to give this terrific orchid a try.

Autumn Laelias

Laelia perrenii flowering at the Fuqua Orchid Center

It's easy to forget during the mid-summer Laelia purpurata explosion that not all Laelias flower in summer. One of my autumn favorites is Laelia perrenii, flowering now in the Fuqua Orchid Center.

Laelia perrenii is a warm to hot-growing Brazilian species that is much less common in cultivation than the enormously popular L. purpurata. The ragged margin on the upper part of the lip gives the flower a totally distinctive look, like torn fabric. It is an undemanding orchid, easy to grow in a greenhouse that is hot, bright and dryish. For most of the year our two plants are hard to spot among the hundred or so Laelia purpurata in our back up greenhouse, but when they flower in autumn I always wish that we had bunches of them. Definitely time to set a capsule on Laelia perrenii. You can see this wonderful orchid on display right now in the Orchid Display House.

The Most Beautiful Orchid

The gorgeous Paphinia herrerae flowering in the Fuqua Orchid Center

I love this plant. Paphinia herrerae is one of a handful of orchids that I think of as the Fuqua Orchid Center's signature plants. It is perhaps my favorite among all of our orchids.

Paphinia herrerae is one of the Fuqua Orchid Center's most beautiful orchids.

The flowers are pendant and best seen from below. It's hard to capture the shimmering translucent quality of Paphinia's petals and sepals. The margins of the petals are ever so slightly wavy--like a delicate handkerchief. Absolutely breathtaking.

Paphinia herrerae flowers in autumn in the Fuqua Orchid Center

We obtained our first plant in 1990 and subsequently propagated it by seed in the Atlanta Botanical Garden's laboratory. The resulting seedlings were an astonishing mixture of plants with pure white, rosy tinged, or deep rose flowers. They are all wonderful.
You won't want to miss the Paphinias in flower. You can see them this fall from October through December in the Orchid Display House.

When to Repot Your Orchid (Part 2)

Now that you know how often to repot your orchid you may also wonder when.
Q: When is the best time to repot my orchid?

A:  At the start of a flush of new root growth.

Why?
Because an orchid establishes very quickly in a potting medium during the part of its annual growth cycle when its roots are actively growing. In nature that span usually coincides with the onset of the rainy season.

Many people are surprised to learn that tropical orchids have an yearly cycle of growth, flowering and rest--a cycle similar in some ways to the yearly growth cycle of temperate zone perennials, but more subtle. Orchid roots do not grow continuously throughout the year.

How do you know when a potted orchid is producing a flush of new roots? They are not always visible.
It's pretty easy, actually, to tell indirectly. Look for a new vegetative (leaf-producing) shoot on your plant. Most orchids produce new roots right around the time the new vegetative shoot appears. Think of the new shoot as a green flag signaling that it's time to repot. I have trained my eye to spot new shoots as I scan our orchid collection. When the new shoots are the size of my little finger, it's time to repot.

A new shoot on Laelia purpurata indicates that it's time to repot.

Is it bad to repot during those months when the orchid's root system is not growing?
It can be. If you damage the root system--and it's hard not to inflict a little bit of breakage during repotting--you can impair the orchid's ability to take up water. It could be months before new roots replace the broken ones. In the meantime your plant may start to decline.

Two new shoots on a Dendrobium Red Emperor 'Prince' that is ready for repotting.

A green flag: the new shoot of an Oncidium intergeneric at the start of its growing cycle. 

Be careful not to confuse a young flower spike and a new leafy shoot! Some orchids produce a flower spike that emerges near the base of a mature shoot--in the same neighborhood as the new vegetative growth. A young spike and a young leafy shoot can look very similar early in their development. If you're not sure it's best to wait. Within a couple of weeks it should become obvious.

What about orchids like Phalaenopsis (above) that don't produce a new shoot? When do I repot my Phalaenopsis?
The best time to repot Phalaenopsis (and other monopodial orchids) is within a month or two after flowering.

Coming soon: a review of commercial potting mixes for orchids.

When to Repot Your Orchid (Part 1)

Q: When should I repot my orchid? Does it matter when?
 Absolutely!

However, there are two ways of interpreting when:
Frequency How often does an orchid need to be repotted? and
Timing During which stage of the orchid's annual growth cycle should repotting be done?

The next two posts will address these questions separately. Today's post tackles the first: How often should I repot my orchid?

You don't need to repot your orchid every year. At the Fuqua Orchid Center we strive to repot our orchids every two years as a general rule. But that is just a general rule. Sometimes one or three years is more appropriate. When I am evaluating our plants with regard to repotting there are always three questions I ask:

1. Is the orchid about to overgrow its pot?
The Oncidium intergeneric (above) has two new shoots (pointing leftward). They look fine now, right? But imagine how they will look next year at this time in the same pot when those two shoots have matured into fat round pseudobulbs. Pretty crowded. Now is the time to repot!

2. Has the orchid's health declined (shriveled pseudobulbs, wrinkled or yellowing leaves) or has it overgrown the side of the pot?
The Laelia (above) should have been repotted two years ago. Yikes. If we wait another year it will be in a serious state of decline. As it is, this plant is so overgrown that it needs not just repotting, but dividing as well--major surgery which could have been prevented had we repotted it in a timely fashion. This plant needs emergency intervention!

Cattleya Mix. Brand new (left) and after two years (right).

Premium Sphagnum Mix. Brand new (left) and after two years (right).

3. Has the potting mix broken down?
Question 3 is especially important. The quickest way to kill your orchid is to let the soil mix break down. Here's what you need to know:

• Most orchids available commercially are tropical in origin, and the majority of tropical orchids are, in varying degrees, epiphytic--they live in trees. Their roots are often exposed to brief drenching rainfall, wind and drought on a daily basis. They are not covered in wet soil.
• In cultivation orchid roots need a potting mix that allows some air circulation. That's why the best orchid mixes are chunky and coarse in texture.
• A high quality orchid mix--either the classic bark/charcoal/perlite type or the newer premium sphagnum variety--lasts about two years, depending how much warmth and moisture it is subjected to.
• Over time bark and sphagnum break down, and if watered at the same rate they become increasingly waterlogged. Ask yourself: Does the mix take a lot longer to dry out than it used to? Is the moss now dark brown or covered with green moss? Is the bark soft and crumbly and dark brown? Time to replace it!
• A constantly saturated potting mix will kill your orchid.

The bottom line: repot your orchid about every two years.

A 'yes' answer to any of the 3 questions above means that your plant is a good candidate for repotting. But maybe not immediately! In order to time your repotting correctly, see my next post.