| I see that this is an older thread, but as a new guy, it's new to me so here's another reply:
Walkerianas receive a lot of sunlight in their savannah-type natural habitat, and more direct sun than most other Cattleyas. In the artificial environments provided by many orchid growers, they get too little.
The amount of light they really want is limited by temperature, but not so much by intensity or duration. In hot weather, morning and later afternoon sun is good. In cooler weather, mid-day sun is also good. So give them all the light they can take throughout the year and reduce it only if you see their leaves becoming yellowish. This will give them the energy they need to bloom. It will also make them grow faster. With optimum light along with optimum watering and fertilizer applications, the one-new-pseudobulb-per-year expectation can become three or four per year.
While we’re on the subject, you may have seen that walkeriana culture info commonly specifies that their roots need to dry between waterings and that the plants need a dry rest period during the winter. I have learned the hard way that this advice is misleading. Following it too strictly can result in damage to the plant.
Walkerianas don’t like soggy conditions or prolonged wetness in their roots any better than other Cattleyas do. Maybe they like it less. And maybe they like it even lesser in the winter. That would be a better precaution. If you let the roots dehydrate either in summer or in winter, they will die. Where walkerianas live in the wild, there is very little rainfall in the winter, but their roots do not dehydrate because they become wet with dew during the night. They never go for long without water.
Walkerianas can do well mounted, provided that they are in a continuously humid environment. In most artificial environments, they do best in wooden baskets full of medium to coarse fir bark. Then, they can receive all the water they need and their roots will be adequately ventilated at the same time.
During summer, when I keep them outside, I water them every morning unless it rains. In really hot weather, the medium can dry out too much even by the end of the day. Under these conditions, it is helpful to cover the top of the medium with coconut husk chips to help conserve water.
Indoors during the winter, less water is needed because the medium dries out more slowly. I water maybe every three or four days, but use a spray bottle on the other days to wet the surface of the medium and the sides of the basket.
That’s what works for me. Watering schedules must suit environmental conditions, which are not all the same as mine.
I use an organic fertilizer with every other watering in the spring and summer, less in the fall, and very little during the winter.
The bottom line on the blooming of walkerianas is the same as for any orchid. It is just a matter of meeting the plant’s needs for light, water, and nutrients. The critical deficiency in most cases in light. As with other Cattleyas, a healthy, blooming size plant that doesn’t bloom is not getting enough. As has been mentioned above, there are also genetic differences from one plant to the next. Some grow more vigorously and bloom more readily than others.  |