The Genus Encyclia–Part 1, Introduction and general notes on cultivation

Picture of backlit Encyclia cordigera flowers
Encyclia cordigera var. rosea

Winter, and the subsequent slowdown in garden activity, has given me the opportunity to dig through old photos and think about a more detailed series of posts than I usually write. This series on the orchid genus Encyclia was adapted from a talk that I gave to the Triangle Orchid Society and other local North Carolina orchid societies. I’m currently planning to break it into five or six parts, to be posted over the next few weeks. Apart from this introduction, I will focus on specific plants from three main regions of Encyclia biodiversity and then conclude with a post on Encyclia hybrids.


Encyclia is a genus of neotropical orchids whose natural range extends from Florida to Argentina. There seem to be three main regions of Encyclia biodiversity: the Caribbean islands, Mexico and Central America, and the Brazilian shield south of the Amazon basin. Encyclias are characterized by heteroblastic pseudobulbs (see below) which are often tightly clustered, 1-3 strap-like leaves which may be leathery or rigid, and flowers with the lip not fused to the column (unlike Epidendrum, in which Encyclia species were previously classified).

Picture of Encyclia cordigera plant
Large pseudobulbs and leathery leaves of Encyclia hanburyi

Encyclia flowers are generally borne on long, upright inflorescences which are sometimes branched. They are usually pollinated by bees and are often strongly fragrant with colors in various shades of white, purple, and yellow. Apart from the flowers, the pseudobulbs of Encyclia plants are probably their best feature. Heteroblastic simply means that the pseudobulb is formed from two or more stem segments of unequal size, and since Encyclias often grow under quite harsh conditions, the water-storing pseudobulbs are often large (up to the size of a large hen’s egg) and glossy. A well-grown Encyclia plant in flower gives an impression of both toughness and elegance.

General cultivation notes

The following constitutes instructions for successfully growing most Encyclia species. When considering specific species in later posts, I’ll make note when a plant’s growing requirements differ from these instructions.

Picture of Encyclia tampensis in the wild
Encyclia tampensis growing on a tree branch in Everglades National Park

Encyclias typically grow as epiphytes or lithophytes, often in exposed situations, at low to moderate altitudes. Consequently, they do best when grown in free-draining media under bright light (though generally not full sun) and with plenty of air movement. Indoors, try growing plants on a south-facing windowsill and/or close to artificial lights. Consider putting plants outdoors in summer. In my greenhouse, I have found that the light diffusion offered by 8 mm twin-wall polycarbonate and a thin layer of dirt is sufficient for most species, without need for additional shade cloth.

Potting media should be open and long lasting. A combination of bark chunks and coarse perlite is the most common traditional choice, but other inorganic components (gravel, stalite, aliflor, scoria, etc) can also be helpful. In my greenhouse, plants do very well in pure scoria (red lava rock), although salt buildup may be a problem in areas with hard water.

Many Encyclia species are adapted to intermittent or seasonal drought, so allow the pot to dry almost completely before re-watering. I find plants easier to manage in terracotta pots than in plastic pots, because rotting roots are the inevitable consequence when potting mix stays wet for too long. Plants can also be grown in plastic or hardwood baskets, or mounted on cork or hardwood. Treefern mounts often stay too wet.

Repot when you see new root growth, not when you see new pseudobulb growth. In some species, roots are produced on immature pseudobulbs, but others root on mature pseudobulbs shortly before flowering. Encyclia cordigera, for instance, initiates new pseudobulb growth in late spring, has a dormant period when the pseudobulb is mature, and finally produces new roots in late winter/early spring shortly before flowering. If you repot E. cordigera in spring and damage the existing roots, the new growth will struggle for almost a year before forming new roots.

Pests and Diseases

Apart from rots associated with cold and overwatering, Encyclia plants are generally free of diseases. They are susceptible to insect pests, though. Aphids, mealybugs, and soft brown scale can badly damage inflorescences, but they will not usually kill a plant. They can be controlled without damaging tender flower buds by spraying with horticultural soaps. Bees can be pests when plants are grown outside, because they will efficiently pollinate all the flowers on your favorite plant. The pollinated flowers rapidly fade and lose their fragrance. To avoid this problem, move flowering plants indoors or enjoy them on a screened porch.

The worst enemy of cultivated Encyclia is boisduval scale (Diaspis boisduvalii). An untreated infestation of this species will disfigure and eventually kill most Encyclia plants. These scale insects are common in commercial nurseries that grow orchids with hard pseudobulbs, particularly Cattleya and related orchids like Encyclia, and even when growers have an active control program it is difficult to entirely exterminate the little pests. Great care should be taken when introducing new plants to your collection. Be very suspicious of plants with yellow patches on their foliage, and closely examine the undersides of leaves for fluffy clusters of males. Peel off the dry, papery bracts on old pseudobulbs to make sure that scale aren’t hiding underneath.

In a small collection, it may be possible to control boisduval scale by spraying with relatively innocuous substances (horticultural soap, oils, 70% isopropyl alcohol, etc), but repeated spraying will be required to achieve control. Wipe down leaves after spraying to dislodge the female shells that protect eggs. In a large greenhouse, the big guns (i.e. systemic pesticides) will probably be required.

True confession: I failed to control a boisduval scale infestation in my collection. Ten years ago, my orchid collection was about 80% Cattleya and Encyclia species, including some very unusual and beautiful plants. Boisduval scale got into the collection, probably through a plant purchased on eBay, and I hesitated to use systemic pesticides. We had young children, and my greenhouse is close to our vegetable garden. With my professional background in genetics and neurobiology I am aware of the limitations of safety testing and sensitive to the possibility of subtle developmental and neurological effects in humans exposed to pesticides that target the insect nervous system. Since orchids are a hobby, not my profession, I decided that I would rather cull badly infested plants and grow something else than rely on highly toxic pesticides. Today, there is not a single surviving Cattleya in my collection, but I still grow a handful of Encyclia species. Some have survived multiple scale infestations controlled by frequent spraying with 70% isopropanol and/or insecticidal soap. Surprisingly, a few species have remained completely untouched by the scale insects, even when grown alongside–or even touching–infested plants.

Flowers of Encyclia cordigera, Encyclia randii, and Encyclia profusa
In my collection, Encyclia cordigera (left foreground) has been completely immune to boisduval scale, while E. randii (center) and E. profusa (right) were badly infested and have been culled.

But enough gloom and doom. Hopefully you will never see boisduval scale on your plants.

Up next: some beautiful Caribbean Encyclia species that are worth growing.

Midwinter flowers

Yes, I know that in the United States the winter solstice is considered the first day of winter, but you can’t convince me that the shortest, darkest day of the year isn’t midwinter. My garden, which today sat under low grey clouds, is at its lowest ebb, but in my greenhouse there are at least a few flowers to brighten the gloom. Here are three:

Paphiopedilum gratrixianum


P. gratrixianum is one of the plain-leaf slipper orchid species that have glossy, rather elegant flowers, one per inflorescence. It is closely related to P. villosum (Photo 6 here) which is also flowering this week.

Sinningia bullata


S. bullata was described in 2010 from material collected in Santa Catarina, Brazil, surprisingly recent for such a striking plant. Its species name refers to the bullate (blistered) foliage, but the bright flowers are what draw the eye at this time of year. Unlike many Sinningia species which require a dry winter dormancy, S. bullata seems to grow year-round. New stems sprout from the tuber almost immediately after the old ones die back, and even when not in flower the plant is attractive for its neat foliage with an attractive texture up top and soft woolly indumentum underneath.


Columnea microcalyx (syn. C. gloriosa)


Like S. bullata, C. microcalyx is a member of the Gesneriaceae, the african violet family. This species is an epiphyte from Central America, and its long, trailing stems are best managed in a hanging basket. My plant, started from a cutting about 18 months ago, is covered in buds and will probably look spectacular in about 4-6 weeks, but I couldn’t resist taking a picture of one of the first flowers to open. This species is usually labeled C. gloriosa in cultivation, but Kew considers that name to be a later synonym.


Six on Saturday #68 (12/4/2021)

It has been almost six months, more than a full season of change, since my last Six on Saturday post! Our first freeze was on November 14, so despite the fact that it is 70 F (21 C) outside this afternoon, the garden is in its winter form.

1-5. memento mori and the promise of rebirth


Fallen leaves of Magnolia macrophylla (bigleaf magnolia). The oak leaf at center gives a sense of scale.


The stems and fruit of Musa velutina (pink banana) do not tolerate any frost, but the rhizomes will sleep peacefully under the soil until next year.


The fluffy seed heads of Vernonia glauca (broadleaf ironweed; see picture #3 here) are why this plant is close to becoming a weed in my garden..


At this time of year, it’s easy to see why Iris domestica has the common name “blackberry lily”. See #6 here for flowers.

Allium-tuberosum seeds

Allium tuberosum (garlic chives) is ready to take over the vegetable garden.

6. Winter greens in the vegetable bins


Not everything in the garden is dead.

The Propagator is the host of Six on Saturday. Head over there to see his Six for this week and find links to the blogs of other participants.

A modern vireya hybrid

Photo of a vireya rhododendron hybrid
Rhododendron praetervisum x ‘Doctor Hermann Sleumer’

As a complement to Rhododendron ‘Princess Alexandra’, the Victorian vireya that I wrote about in June, here is a more recent vireya hybrid. This plant is Rhododendron praetervisum x ‘Doctor Hermann Sleumer’, so its parentage is R. praetervisum x (konori var phaeopeplum x zoelleri). R. zoelleri has been known since the 1890s, but the type specimen of R. konori var. phaeopeplum was collected in 1939, and the type of R. praetervisum in 1965 [1]. The cross was made by Richard Currie in his New Zealand garden, presumably in the late 1970s or 1980s. One plant of this cross was registered as Rhododendron ‘Cheeky’ but I am not certain if my plant is a division of that cultivar or a sibling.

I previously grew a plant of R. praetervisum, but it never thrived, flowered infrequently, and died after about five years. I’m hopeful that this plant will exhibit hybrid vigor and, perhaps, inherit heat tolerance from R. zoelleri (native altitude range sea level-2000 m [1]). I purchased it in April, and it grew well in my shade house during the summer and has already flowered twice.

Incidentally, Hermann Sleumer was a botanist at the Rijksherbarium in Leiden who described hundreds of new vireya Rhododendron species in the 1950s and 60s, making him one of the most important names in the modern era of vireya cultivation. Both R. praetervisum and R. konori var phaeopeplum (as R. phaeopeplum) were described by Dr Sleumer.


1. Argent, G. (2015) Rhododendrons of subgenus Vireya, 2nd edition. Royal Botanic Garden, Edinburgh.

Juanulloa mexicana


You really can’t go wrong with a hummingbird-pollinated plant. The little birds are attracted to bright colors–primarily red, but also orange, yellow, and magenta–and flowers adapted to hummingbird pollination generally have interesting tubular or bell-like shapes. The only downsides to the hummingbird pollination syndrome are that the flowers usually lack fragrance, and the plants are often not heat-tolerant; hummingbird-pollinated plants are often native to tropical cloud forests where hummingbirds are most diverse and flying insects relatively rare.

Juanulloa mexicana (syn. J. aurantiaca) is a semi-epiphytic shrub that has all the good qualities of a hummingbird-pollinated plant but also exhibits considerable heat and drought tolerance. The plant itself is rather messy–or “interesting” if we want to be charitable. It has long, poorly branched stems that presumably ramble through the branches of host plants or over rocks in its native habitat. The leaves are widely spaced, and adventitious roots can emerge from almost anywhere along the stems. The roots adhere tightly to any surface they come in contact with (greenhouse benches, other pots, the gravel floor of the greenhouse, etc), and once they become large and woody, they can sprout their own leafy stems. When the plant is grown in a pot, roots will creep over the edge and emerge from drainage holes. The thin leaves are subject to infestations of mealybugs and spider mites, and they drop in the autumn, leaving the plant a leafless tangle of stems and roots for much of the winter.

But when it blooms, I forget how inelegant the plant is. The tubular flowers, which grow on short inflorescences, generally near the end of a stem, are dark orange and nestle in a slightly lighter orange calyx. I generally see flowers during the summer, but the plant can also bloom in winter while leafless. My plant seems to be self-sterile; despite numerous visits from hummingbirds and several attempts at hand pollination, I have never obtained seed.

Fortunately, however, J. mexicana is very easy to propagate from stem or root cuttings. I have used moist sphagnum moss and commercial potting mix with equal success, and I suspect that cuttings would grow just fine in damp paper towels or gravel. Stem cuttings will flower more quickly, but root cuttings might give you a more interesting specimen. One of my plants, grown from a piece of root that invaded a neighboring pot, has produced an above-ground tuber which is currently about the size of a plum or very large hen’s egg. Lignotubers are not uncommon in epiphytic shrubs (e.g. epiphytic Ericaceae), and several species of the related genus Markea produce tubers that are often hollow and inhabited by ants. However, I have been unable to find any literature describing tuber growth in Juanulloa. I am unsure if this is normal (i.e. a lignotuber) or abnormal growth (i.e. a burl or something similar). If anyone has any insight, please let me know. I’d be particularly interested to know whether seedlings produce a similar tuber.

Tuber at the base of a Juanulloa mexicana plant grown from a small root cutting. Note the new leafy stem sprouting from the old root at lower right.
Another view of the tuber