Okay to water Den. nobile?

[smweaver]

This might be a dumb question, but once I see buds emerge from the sheaths on my Dendrobium nobile, is it safe to start watering again with plain (unfertilized) water without the fear of having to see anything turn from a bud to a keiki? Thanks!

Steve

[gnathaniel]

Originally Posted by smweaver

This might be a dumb question, but once I see buds emerge from the sheaths on my Dendrobium nobile, is it safe to start watering again with plain (unfertilized) water without the fear of having to see anything turn from a bud to a keiki? Thanks!

Steve

Yes, it should be. Once the buds develop they can't turn back into keikis AFAIK. A lot of people (myself included) keep watering nobile and most other plants in this section throughout the winter with no ill consequences. I've seen no clear data on the precise bloom cues for these species, but most sources seem to indicate that temperature (including daily gradients) and lack of excess Nitrogen are at least as important as providing a drier rest during the winter.

My own thoughts are that you don't want to provide roots with water they can't or won't use, especially if temps are cooler. This can lead to root rot, which will stress most plants into vegetative propagation, a more 'sure thing' for genetic survival than sexual reproduction. How well your plant's roots can deal with water depends on whether or not the plant is actively growing; a lot of cultural factors such as light, temperature, humidity, air movement, and how it's potted; and whether or not it's kept its leaves (which will continue to transpire and lose water while on the plant). Since nobile tends to keep its leaves for more than one growing season, I water mine a bit more this time of year than I do for say, parishii, which is pretty much leafless by now. Another good indication of need for water or lack thereof is how much the canes are shriveling. Very shriveled canes will probably stress your plant and reduce initial growth somewhat in the next growing season. Hope this helps, and enjoy those blooms!

--Nat

[smweaver]

Thanks, Nat! The plant has kept around 85% of its leaves this winter, in spite of the fact that I've been giving it very limited amounts of water for the last four months. It did receive a large temperature variation from mid October to late December, when the night temperatures dropped to around 45 and the days warmed up to the 70 to 75 degree range. At that time it got lots of sun, no fertilizer and was watered maybe once every three weeks (lightly). The pseudobulbs have only slightly shriveled, so I don't think that the plant's in any great danger. But still, since the buds have clearly differentiating and emerged from the sheaths along the three oldest pseudobulbs over the last few days, I wanted to make sure that nothing bad would likely happen before I started watering the plant again. It came from South Florida, and none of the older pseudobulbs had any remnants of old flower spikes on them. So I'm pretty excited that the plant is seeing fit to bloom this year. Thank you again for your advice.

Steve

[gnathaniel]

Sounds like you're doing great with it, Steve! How many buds are showing on the blooming canes, and what color form is the plant supposed to be? My alba nobile is going crazy with buds right now, but unfortunately my typical color form nobile (which I think I like better) is only a smallish seedling that doesn't seem likely to bloom at all this year. Oh well, it'll get bigger!

--Nat

[smweaver]

Nat, it's supposedly a standard-colored variety (at least that's what I'm assuming for now, since there's nothing more on the label than the genus and species name). It looks like there are around twenty to twenty-five sheaths with two to three buds per sheath. This is my first experience with D. nobile, so I'm not sure whether I have a small plant, a juvenile, or a full-size adult. The three largest canes are almost two feet tall (they're the ones with the buds). I also have an alba variety (virginalis?), which is about a third the size of the one that's getting ready to bloom. Even though the alba is much smaller, it (unlike the standard one) does have the remains of old flower spikes--although it's not getting ready to flower, even though they've received the exact same treatment since I got them.

I'll be interested to see the alba blooms on your plant. It's the one plant out of the two that I have that I really wanted to flower (not that I'm complaining).

Steve

[gnathaniel]

Wow that's a lot of blooms! And here I was about to start bragging on what looks like a paltry 40 or so buds developing on my alba. Nice growing!

I think from your description that you probably have a full-size adult plant. All the literature I've read on nobile indicates that 2 feet is usually the maximum length for individual growths, though it might vary somewhat depending on culture. My big one has 3 mature growths at that size but only two budding out right now. I'm crossing my fingers that the third mature growth will throw another smaller flush of blooms later on in the spring.

I'll definitely try to get and share some decent pictures of mine when it blooms. I was told it is a 'true' alba rather than var. virginale, which has a green patch in the throat. Which I was initially a little disappointed about since I had been looking for virginale. Not that I'm complaining now...

That's interesting about your alba not budding yet despite identical treatment. I have 3 different clones of Den. loddigesii; one lost all its leaves a while ago and has nothing noticeable going on with it, the second has kept its leaves all winter (though they're all purple and wrinkly now) and looks to be budding out opposite each leaf, and the third has kept its leaves and seems to be sending out a new growth from the rhizome. They all grow next to each other with near-identical light levels and very little water right now. I guess individual genetics plays a significant role in how they respond to environmental cues and cycles.

--Nat

[smweaver]

Well, I THINK that my plant has a lot of buds forming. But to be honest, with all of those canes and leaves, it's a bit of a challenge to perform an accurate count. So you still might have the winning plant as far as quantity of flowers go. :-) By the way, do you know if D. nobile's blooms are supposed to be fragrant? Just curious.

I've been meaning to try D. loddigesii. All of the pictures that I've seen of the plants when they're loaded with blooms have been quite impressive. The only other dendrobium species that I have are speciosum and signatum. I think I might have just enough room for a modest-sized loddigesii.

Your alba (I didn't know that virginalis wasn't a true alba) sounds like it should be beautiful. Good luck!

[gnathaniel]

Hi Steve, most modern sources I've read just vaguely indicate that nobile has a nice fragrance, however a book from 1895 I found on Google Books says nobile has an 'odour of hay in the evening, of honey at noon, and Primrose in the morning.'

My big nobile started opening its buds a couple of days ago and I haven't detected any fragrance, but if the flowers aren't mature enough to be fertile they're probably not trying to attract pollinators yet. The flowers have a greenish-yellow tinge to the sepals but no spot in the throat like the virginale form. While I'm sure it will look nice in full bloom, I still feel a little disappointed with the poor chromatic contrast in the flowers since that's one thing I like so much about the typical nobile... I guess this is sort of a case of the grass being greener on the other side! Anyway, I'll try to get some decent pictures of it tomorrow or the next day.

I definitely recommend loddigesii, it's the species that initially got me interested in this type of Dendrobium. They keiki freely with copious roots and will quickly cover up a slab or hanging basket, but other than that they stay pretty miniature. They also smell nice though not very strong, kind of a mild soapy-rosy aroma on the one I had in bloom last spring. Oak Hill Gardens, Carolina Orchids, and Kawamoto Orchids all carry it if you're looking.

I also HIGHLY recommend parishii out of all this group; it's very compact with fat bare canes that look like white bones this time of year, then lots of fuzzy purplish flowers smelling like raspberries for weeks in the spring. Looks striking in any season and seems really easy to grow, I treat mine the same as nobile except less water and slightly warmer temps in the winter. I think Oak Hill has this one as well.

How easy have you found signatum to grow? This is one I'd like to try eventually. Does yours have any keikis you'd be interested in trading when the weather warms up?

--Nat

[smweaver]

Nat, my signatum doesn't have any keikis, but it's still listed on RF Orchids' web site (where I purchased my plant).

D. signatum's been an easy plant to grow, and the one I have is about half the size of the large nobile plant. It hasn't produced spikes yet--and I don't see any remnants of spikes on the older canes either. But it's been getting the chilly-and-dry treatment for the last four months, so maybe there's still hope that I might see some blooms in the spring (of course, there's also the possibility that maybe it does NOT like cool, dry winters, and I'm just helping it move towards an early death by treating it like the nobiles :-). If it does produce a keiki, I'd be more than happy to send one your way.

Steve

[gnathaniel]

Thanks Steve! I'll for sure check out RF Orchids. I'm going down to Tampa in March, maybe I can convince the wife to take an orchid-gathering side trip further south...

I think you're probably treating your signatum just how it wants to be this time of year. From what I've read the natural ranges of nobile and signatum coincide quite a bit, with nobile tending to somewhat higher altitudes than signatum. I bet if you just keep up the dryness and coolish temps for a while more you'll see at least a few buds this spring.

--Nat