Odm. Rawdon Jester (Odm. grande x Odm. Williamsianum)

[sand_tiger86]

I believe these are actually Rossioglossum these days, as Bruce told me a few years back, but, after years of searching, I've finally found a vendor that sells them! Seems like no one has them, so I was absolutely ecstatic. I ordered one, of course, but I'm stuck with not knowing what to do with it. Does anyone have any experience with these? The internet hasn't been a lot of help, but I have read a couple of times that they might be cool-intermediate growers. That seems a little odd to me, though? I always thought Oncidium alliance orchids were warm growing. (or is this not Oncidium alliance at all?) Anyhow, any bit of information regarding the culture of this guy would be much appreciated! Temperature, light, etc.

[Cjcorner]

I did a search on Rawdon Jester care info and came up with a wonderful "plant of the month article". Pretty much it said this one likes it sunnier than normal oncidiums. Water and fertilize (with some cal mag added in) every 5-7 days. Can handle temps up to mid 90's with good air movement, and down to mid 40's in winter if daytime temps are 65-70. Hope this helps...seeing all the pics of the flowers has me wanting to add one to my collection. So few oncidiums are that heat tolerant.

[orchidsal]

Yes the Rossioglossum Rawdon Jester does prefer it on the intermediate side, but it will take the heat (above 80 degrees) for many weeks if it must. My Rawdon Jester is starting its first spike and I have had it for a little over a year. I am glad you did not get the Rossioglossum grande as it can tolerate heat for relatively brief periods of time only and it really should stay at less than 80 degrees F. always. I have it in bright mostly indirect sun and with a plant in a 5 inch plastic pot (medium bark) I water every four days this time year when in full growth, less in winter. Allow to dry somewhat between waterings. I fertilize once a week with MSU Fertilizer and alternate this with Fish emulsion with seaweed every other week. Keep in mind that that the Rossioglossum are from various mountain elevations in Mexico and central America. This is why they prefer cool to intermediate temperatures that are quite moderate in range. Oncidiums range from the mountains down to sea level in Latin America and you will therefore find more 'warm' growers in this group. Hope this helps. AL

[sand_tiger86]

Thanks for the help guys! So is it safe to say that I shouldn't summer it with my Vandas and Catts outside here in Texas, where the temps stay consistently in the 90's (at minimum most days)? Maybe I should put it in the windowsill? (Western facing) They also seem a little fussy to get to spike from what I've read - is that true, Orchidsal? (or at least the grandes do - maybe since this is a hybrid it's a little less finicky?)

[orchidsal]

Rawdon Jester does seem easier to grow and spike than the Rossioglossum grande. My grande went through a bad patch last summer were it could not take the 90 degree F. highs in my greenhouse. I brought it in the air conditioned house at no more than 78 degrees and it recovered and brought forth a new growth. So far this season the Rawdon Jester is growing a new growth and spiking. The grande is sitting there with no change since fall even though the temperature is never above 80 degrees F. now in the greenhouse. I would personally not leave your new Rossioglossum out in Texas heat. Even if it tolerates it I would wonder about growth and blooming. Inside may be your best bet. AL

[serama]

I killed a couple of Rossioglossum grande before I found out about their particular needs. I think you will struggle to keep them alive in Texas but here's what I found out, which I hope will help you.

Rossioglossums are indeed in the oncidium family, but they used to be included in the genus Odontoglossum and not in Oncidium because their habitat lies at such high altitude that it's not shared by many oncidiums. The genus only contains a few species that can be hybridised among themselves, but which won't interbreed with either oncidiums or odontoglossums as they are genetically quite different from them, which also explains why they need conditions that are quite different from either odontoglossums or oncidiums.

They live at high altitude like odontoglossums but unlike these (which always live in cloud forests and have access to plenty of moisture all year round) they need a very dry rest like some oncidiums do. They can't survive high temps for long and, even though they can cope with intermediate temps during the growing season, they need a very long, cold and dry winter rest. The reason that they're not more widely available is that they're tricky to accommodate in a mixed collection. They like the temperatures that masdevallias and odontoglossums enjoy, but they can't stand the same level of humidity, particularly in winter. They also need light levels that are closer to oncidiums and cattleyas but they'll burn and dehydrate easily if the high light intensity results in high temps, which is often the case when you grow them under glass. Also, in winter they need a dry rest that should last at least 4 months but ideally should be closer to 6 months. During this time it's tricky to give them enough moisture to stop them from shrivelling too much because the medium will stay too wet even if you give them just a little bit of water. This is because of the cold temperatures and will result in the root system rotting without you even noticing.

The best way of growing them is small pots with well an open and well-drained medium. Place them somewhere with good air movement (for example among oncidiums) in the cool section of an intermediate greenhouse while they're actively growing (roughly May to October here in the UK) and then in a cool, moist greenhouse among pleurothallids while they're resting. There you can put their pots into hanging basket during the winter and lift them close to the glass, where they get more light and stay out of the range of accidental splashes while you water the rest of the plants. DO NOT WATER THEM IN WINTER, the ambient moisture is enough to keep them going but you can also give them a little water once a month when you know you're going to get a few sunny days in a row. Move them back onto the bench in March to stop them from getting burned once the sun gets stronger, but don't start to water them until they show a new growth that is nearly an inch long and starts to produce the first few nobs that will turn into roots (similar to to what you do with Catasetum and Cycnoches), as the new growth will rot VERY easily.

[sand_tiger86]

Thanks, serama. Very enlightening stuff...now I'm starting to think I should've stayed away from it, though! After reading that, my Vandas seem like looking after a Phal. Lol
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[sand_tiger86]

Well, I just got it in the mail today! It's beautiful and healthy. Very firm leaves and not a wrinkle on the P-bulbs. I think I'm just going to wing it and treat it like any other orchid, but less heat. Water only when medium is nearing the dry-point, plenty of light but in this particular case I'll try to make sure it doesn't experience high temps. for very long. I'll also attempt the whole no water during winter thing, but I highly doubt that'll work out here in Texas. Even in the winter it gets warm during most days (very cool at night, though) and I don't think anything could survive a 3-6 month hiatus from water.

[serama]

Yep, that sounds sensible. The long and completely dry rest is only a good idea if you can give it cold temps. Keep it dry and only give it a bit of water occasionally. The pseudobulbs do shrivel quite a bit during the rest, but they plump up very quickly once they get watered again.

BTW, have you ever heard the term "hybrid vigour"? Odm. Rawdon Jester is the finest example of this and usually grows without any fuss, twice twice as big and flowers more prolifically than either of the parent species, which often are quite tricky to grow well.

Good luck.

[sand_tiger86]

Yep, that sounds sensible. The long and completely dry rest is only a good idea if you can give it cold temps. Keep it dry and only give it a bit of water occasionally. The pseudobulbs do shrivel quite a bit during the rest, but they plump up very quickly once they get watered again.

BTW, have you ever heard the term "hybrid vigour"? Odm. Rawdon Jester is the finest example of this and usually grows without any fuss, twice twice as big and flowers more prolifically than either of the parent species, which often are quite tricky to grow well.

Good luck.

So when you're talking about the months of dryness, is the only to combat the extreme cold so the roots won't be rotted if watered? Or is it just a necessity in the plants DNA that it go through a long dry spell in order to flower/grow?

And yes, I have...which is why I got a hybrid instead of the actual parent plant(s). This one sounds tricky enough - I could do without a species! (I don't grow any species plants, because as you mentioned, the hybrids are usually more prolific growers, have brighter colors and are much less fussy).