Having problems with my Promenea

[camille1585]

I have a little Noid Promenaea that I picked up for nearly nothing at a local show last October. Tag says it's a yellow hybrid, that's all. Despite me knowing nothing about this genus it's been growing quite well. Watering has been done by trial and error, I don't know how much they need! Judging by the pleating, I need to water more.

Anyway, in the past week or so several of the leaves coming off the top of the bulbs have gone yellow and brown. I don't think it's normal leaf drop, the affected leaves are on the more recent bulbs. And I'm also having trouble with the center leaf rotting on half grown growths.
Any ideas?

[ezil]

What I remember of my (mostly unsuccessful) promenea growing days is that they are fussy about water quality and temperature. They hate to dry out too much, and being wet too long. They like cooler temps., and that was the problem when we moved to this apartment. Cooler temps. may help with increased humidity and good ventilation. Since it's a noid, it'll have to be by trial and error. Good luck.

[Discus]

A Promenaea stapelioides (I think) was one of the first plants I noticed at my first ever orchid society meeting; Promenaeas were noted to be a right bugger to grow by two very experienced growers, particularly with respect to humidity and water.

Sorry but it sounds like these guys are a bit finicky :/ A quick browse through OrchidWiz suggests a preponderance of yellow in this genus and its hybrids :/ Did you check the Baker culture sheets in OrchidWiz? Sounds like they need a somewhat drier winter, although with high humidity and never actual dryness....

I like the way the guinea pig is getting in on the photography action there.

[camille1585]

If they like cool temps, maybe I'll pot it up like a masdie, i.e. in a clay pot placed inside a slightly larger one, with damp sphag between the two. Keeps the clay cool, and so cools the roots.

This one is going to be interesting come summer, heat accumulates really easily in my apartment. In the winter that's fine (I rarely turn on the heat) but in the summer it gets HOT!

But I can't imagine heat being the issue now. The temperature inside has been at 18-22°C since I got the plant, humidity 60-70%, growing it with the Phals. I just got a hold of the water analysis for my town today, I have to pore over it in detail. But from memory, the basics are pH 8, hardness 4°dH, and EC is 0.17 mS/cm (which I calculated to be very roughly a TDS of 100ppm). Maybe I'll stay mixing in distilled water with the tap water for this one and the masdies.

As for the piggy, he was expecting me to feed him, not put a plant on the floor! And he's always very curious about everything.

[Bud]

I have two kinds in my collection: one hybrid and one specie...
I make sure it is evenly moistened...and wait til its dry then water it...we have the same kind of media; I put it in my bathroom window (west facing) to get the hot shower steam and then the cold evening breeze with the window slightly opened...
weekly Algoflash orchid fertilizer alternating with seaweed mix and worm tea mix...
I didnt give it any winter rest...(I dont know...should I?)
The color of my leaves turned hunter green in the winter and in the summer a bit lighter and a bit transluscent when it gets more sun
it didnt flower for me last year maybe because it sulked when I transplanted it and disturbed the roots...

---------- Post added at 06:50 PM ---------- Previous post was at 06:40 PM ----------

"Promenaeas are very forgiving little plants that, given suitable conditions, will rapidly develop into specimen plants. A 100mm. Potful could easily produce over thirty relatively large blooms.

Generally if you can grow Zygopetalums well you should grow Promenaeas to perfection. The only cultural requirement that they seem to be fussy about is their need for heavy shade. They are tolerant of a wide range of temperatures but are stressed by extreme heat ( withering rapidly if left dry) and exteme cold( leaf dropping and spotting) especially if not kept under cover. I can grow them in Sydney both in a glasshouse, heated to a minimum of 10 degrees celsius, or outside year-round under cover. The ones in the shadehouse grow best in summer while the ones in the glasshouse grow best in winter. Keeping the foliage dry on winter nights, as you would for most other genera, seems to be more important than temperature.

Promenaeas will grow in almost any medium provided that it is airy and retains some moisture. Most growers seem to use either pine bark, sphagnum moss and styrofoam, pine bark and pebbles or a combination of these. I use fine treated pine bark (70%) and fine pebbles to which I add a small amount of chopped sphagnum and fine styrofoam. Depending on your conditions and watering regime you could improve your culture by using a layer of medium grade bark in the bottom of your pots to speed the drainage for wet climates and heavy waterers. Alternately you can 'top-off' the last centimetre of your pots with sphagnum to retain a little more moisture for those in dry areas or who are miserly waterers.

Promenaeas respond well to fertilizer when they are in active growth. Most liquid fertilizers on the market give good results provided that they are applied as a weak solution. I do not pot in straight sphagnum but most of the growers that I know who do seem to avoid organic fertilizers and prefer to use very weak chemical fertilizer .

Promenaeas prefer not to be allowed to dry out for long periods so regular watering is the order of the day. I like to see the green bulbs begin to wrinkle a little before I apply more water. Like most other orchids too little water is far less harmful than too much . A well grown Prom. hybrid should flower in a 50 mm. tube in the second summer after leaving the flask, some will flower even sooner while species could be expected to be a little slower. It would be prudent to keep water away from the new growths as they form to discourage rot - as you would with any other orchid.

The soft leaves and relatively large juicy buds and flowers are very attractive to grubs, slugs and snails but otherwise they are relatively pest and disease free. An unusual feature of Promenaeas is that once a flower has been pollinated the flower fades but remains alive during gestation. This makes your precious seed capsule even more appetising to those crawling nasties. "
- Sutherland Orchid Society-

[camille1585]

Funny, I was JUST reading that on internet!

But I still have no idea why there are leaves yellowing.... I never see this mentioned anywhere as a side effect of bad care.

[Bud]

I dont think you are giving your plant "bad care"...give yourself more credit...it must be something in the media...try cleaning out the roots and put into fresh media...try distilled room temperature water ... until you see that it is recovering ...then continue on your regular regimen

[nenella]

Just my 2 cents worth....
I don't & have never had one but Buds phrase "Generally if you can grow Zygopetalums well you should grow Promenaeas to perfection"Really struck me as I thought of my Zygo when I looked at your photos before reading Bud.

Another possibility is it doesn't like alot of fertilizer? I say this always in ref to the Zygo I have I try to only use fert once in a while & have noticed better growth since. Also in your pic you have a young growth which is brown at the bottom (looks like it"s dry & not rotted?) I have had this happen to a growth on my zygo and saved it - (by keeping the growth above the medium (styrofoam) the growth is growing, although no sign of a spike.

Your plant looks like it has plenty of good roots, I can't tell you to repot as have no idea ( have you checked them?, although it's probably one of those orchids that don't sprout new roots on old growths) but if you keep those new growths from getting/staying damp, I think you will resolve a lot of your problem. Good luck.

[camille1585]

Hmmm, thanks for that insight. Perhaps I should stop watering it from above (even though I'm careful about not getting the plant wet) and start soaking it instead. I'll also cut back the fertilizer somewhat.

Some of those brown things are rotted growths, from before I was tried to be careful to avoid wetting them.

The roots are amazing though, I eased it out of the pot to have a look.

[Carpe Diem]

Can't comment on the plant, but love the piggy!