Still, these are among my most treasured plants, especially some of the hybrids I was lucky enough to collect a few years ago, when ordering plants from the UK was less problematic. Some are more successful than others, and I always keep a plant or two of the rarer varieties in the cool greenhouse over the winter for insurance purposes. I have been growing Bletillas from seed over the past couple of years (see pics in the previous post on raising plants from seed), having discovered that the dust-like seed will germinate if mixed with fine sand and sprinkled over the surface of milled sphagnum in a clear plastic container; most other orchids require flasking under sterile conditions for seed propagation. I'm excited about the possibilities this opens up for hybridizing. Now all I need is more room in which to grow the young plants to maturity...
Other than a few articles online (notably one written several years ago by Clark T. Riley on orchidmall.com), and a chapter in the excellent book, Growing Hardy Perennial Orchids by William Mathis, there isn't much information available on growing this genus, so I've learned a lot by trial and error. One revelation came two years ago when I visited a nursery in Richmond and saw B. striata being sold as a marginal aquatic plant, seeming perfectly happy to sit with roots immersed in a deep pan of water; it appears that while they're in full growth during warm weather, overwatering isn't really an issue. Conversely, although the rhizomes can't take too much moisture when dormant, I did discover that storing the bulbs totally dry, as per pleiones, some zephyranthes, etc., is definitely not successful, either. At least partial sun (in combination with adequate moisture) seems to produce better growth and flowering than the usually recommended shade.
There are numerous varieties of B. striata, apparently the sturdiest of the tribe: this image shows both the straight species and the variant with a white stripe along the leaf edge.
To the right is the pure white cultivar (not a particularly good image); some forms have a bit of a purple flush on the tip of the column. There's also a pure white clone with variegated leaves, but the stripes are not very visible in this photograph:To the left is a variety called "Kuchibeni", also marketed as "First Kiss". It's as close as Bletilla striata comes to what is known in Cattleya breeding as a "semi-alba", white with a colored lip.
"Lips", the variety of B. striata pictured below, is unique in that its flowers are peloric, a word which describes their tendency to approach radial, as opposed to the usual bilateral, symmetry. It's this mutation which gave rise to "splash petal" cattleya breeding, and which brought about the varieties of Sinningia speciosa which are now known as florist's gloxinias. It's a strong grower, but has been shy about blooming. Most disappointing, however, is that the column is consistently malformed, producing neither viable pollen nor a functioning pistil, so the hybridization I envisioned appears unlikely.
I also grow a newer variety of striata called 'Murasaki Shikibu', the flowers of which are lavender with a much bluer cast than the other varieties. I made several crosses last summer using this cultivar, and the seeds have germinated, so I hope to eventually expand the color range. (Note: the image below is not my own, but I can't locate the original source.) It pains me to post the next two pictures, since the subjects have gone to "plant heaven", but B. formosana is an important species in terms of hybridizing, so shown here for visual comparison are both its alba and lavender forms:
The third species which is generally available is Bletilla ochracea (left), which is available in various shades of yellow and cream. It's not as strong a grower as striata, but holds its own, coming into growth and blooming later.
B. ochracea, in my view, is more important for its potential as a parent; 'Coritani' (left, B. ochracea x formosana) is a stronger grower than either parent, and often produces a second crop of flowers later in the season. 'Penway Sunset' (right, B. ochracea x szetchuanica - a species I've never even managed to flower), is a sturdy hybrid which produces more blooms per stem than any other in my collection.
'Penway Rainbow' (left), a complex hybrid (B. 'Yokohama', which is striata x formosana, crossed with B. ochracea), is, in my opinion, the best of the yellows so far, with strong coloring and a hardy, vigorous constitution. It should be noted that many of the grex names include the word "Penway" and were registered by the holder of the British National Collection, R. Evenden (This is as much of the name as I've located in my research so far).
Another very successful hybrid with ochracea is "Brigantes", the cross made using striata. I have three clones; one is nearly indistinguishable from striata, and another is a beautiful lavender with very rich lip coloration. The third called 'Moonlight', has striata 'alba' as a parent, and has been a much weaker grower than the others. I'm hoping to remake it (or something similar) this year using some of the stronger yellow hybrids listed above.
Two other species have been involved in hybridization, one of which, szetchuanica, I have attempted to grow. It apparently experiences a long period of dormancy, which shows up in its hybrids as a useful trait. This tendency also seems to make the species difficult to carry over the winter, due to its need for some moisture, but not too much. My experiences with B. szetchuanica have been similar to those I've had with Pleiones, in that there is grave danger of rot due to imperfect watering at the inception of growth in spring, and second chances are not given. It has produced some gardenworthy hybrids however, all of which show greater than average bud count per stem, with the flowers arrayed alternately, each facing more or less away from its predecessor.
Bletilla 'Penway Paris' (left) is striata x szetchuanica; 'Penway Dragon' (below) is formosana x szetchuanica; and 'Penway Starshine' (below, right), is 'Yokohama' x szetchuanica.
Rounding out the list of registered primary hybrids are those created using the elusive B. yunnanensis, which I've never seen offered for sale. I do have a plant purchased several years ago from a source in California which lists it as an unnamed species, "perhaps yunnanensis", but it's such a weak grower that it has yet to produce an inflorescence. Three of its hybrids, however, are growable, hardy plants, and one of these, 'Penway Rose' (left), is very distinctive in form and color, being a hybrid of B. ochracea with this species. 'Penway Princess' is yunnanensis by formosana, and 'Penway Imperial', a particularly strong grower which I have somehow neglected to photograph, is yunnanensis by striata.
Given all of their attributes as garden plants, it surprises me that Bletillas have not gained more popularity with gardeners in the temperate zone. Perhaps it has to do with the size of their blooms, or their limited blooming period, but their contribution to the garden continues through the fall with their pleated, arching sheaves of foliage, which is variegated in several varieties. My goal in seed propagation is not only to broaden the color spectrum of the available hybrids, but to produce F2 generations from the primary hybrids which combine the appearance of the more difficult and/or unavailable species with the sturdier constitution of Bletilla striata. I'm also attempting hybridization with Calopogon species, if for no other reason than the fact that I like the name given to this type of cross by the AOS - "Calopotilla".
In the time it's taken me to assemble this post, our usual frost-free date has passed (but only just), and I've uncovered the Bletillas, which are a little etiolated (they look like expensive white asparagus this morning), but appear none the worse for wear. I'm keeping my fingers crossed; in my book, emerging Bletilla pseudobulbs are right up there with Magnolia x soulangeana blooms as sure-fire harbingers of an April freeze!