First off, what kind of orchid are you growing?
What media are they planted in?

Shriveled leaves and pseudobulbs may not always indicate lack of water, it may be a sign that the roots have gone bad. The planting media has gone bad. Overwatering will just exacerbate the problem.

What you are describing could be too much water or not enough. Pull the plants out of their pots and look at the roots. If they are brown and soft, the problem is over watering. Fresh bark and watering once a week will solve the problem. If the plants are in small pots, 3" or smaller, they need to be watered more often but if they are in the standard sizes, once a week is best for most of them.

Nick

I'm growing odontioda, miltassias, various other types in the oncidium alliance, brassia (a really thirsty type), beallara, cattleyas, epidendrum, one paph, and some phals. I've checked all the roots recently and repotted the ones that seemed to need it. I grow only in clear plastic pots so I can see the roots. The ones that seem to need more water are the ones with the little hairy roots. They aren't brown and soft at all. So, do all you professional growers never see shriveled PBs? My own theory is that I don't have a clue how long the orchids I've been buying (I admit it, off the half price shelf) have been in the store, nor if they've gotten the optimal potting media and water schedule. Once they've started down the path to dehydration, those bulbs are going to shrivel either in the store or my home. Just to state again, I've checked all the roots within the past couple months. Maybe I'll do it again.

If you have healthy roots, you are not over watering. Keep up the twice a week plan, I see nothing wrong with it.

Nick

Andrea, what I have found is that older bulbs are capable of ultimately shriveling away to nothing simply due to what I interpret as a combination of age and culture. And it is similar to the way some perennials die out in the center as they spread outward and need to be divided every so often (grasses come to mind). I find this particularly true of plants grown indoors. But even in a greenhouse: I've had plenty of plans coming from growers where "ancient" bulbs were buried in the potting media as a matter of course, and they were alive but shriveled. Existed that way for a good while too.

For culture, I would also point out that you are growing a wide range of plants together that have wide ranging temperature requirements. I'm not sure of the overall conditions of your sunroom, but my eye particularly caught the juxtaposition of Odontioda (cooler) and Phals (warm). I have tried some cooler growing oncidiinae here and there in my warm collection and they always had a wilted and shriveled looking.

So ultimately I believe it is a combination of factors. Under good conditions, these things can turn into monsters. But even then the older bulbs can still look a bit janky.

I agree with Terp. It is not conflicting information.It is the little problem of trying to grow orchids which come from a wide range of climates in the one set of growing conditions.

The only variable you have is the mix and pot size.

Sooner or later growers give up trying stuff that is not rewarding in their conditions and concentrate on the Genera that thrives.

To grow "everything" well you might need something like ten different sets of growing conditions. Nick is getting there.

Just think of that word "tropical" . "Palm trees, sand, sun
and pleasant breezes"
When in fact you have.
Tropical Lowland
Tropical Savannah
Tropical Cloud Forest
Tropical Montane

Then there is the frustration of those easy orchids that "anyone" can grow. In my case it is Zygopetalum.

'Sooner or later growers give up trying stuff that is not rewarding in their conditions and concentrate on the Genera that thrives.' I couldn't agree with that more, I have been preaching that for years.

As far as me getting to 10 different set of growing conditions, I'm too thick skinned to fall for that trick. In the cool greenhouse everything gets soaked in RO water every 2 days except a corner where there are some cold growing Dendrobiums. They only get watered on Sunday, not at all in the winter. You could call that 1 or 2 conditions but it is effortless and does not require switching water or fertilizer.

In the warm greenhouse, the mounties, the Bulbos and Pleuros get soaked every 2 days, again with RO, they are grouped together. All the others get soaked every second time only. Again no shifting of water or fertilizer, just refraining from watering 1/2 of the GH every second time. No effort.

Outside, under shade cloth everything gets soaked with tap water when I'm in the mood. Usually every 2 days as most are mounted but I may do it daily when it gets hot, weekly in the winter, sometimes even less when it's foggy and drizzly. I do have some that are in bark, they sit in a group and get watered every Sunday only.

That gives me 3 different watering areas, all the plants that live there love it, the ones that don't love it have long ago gone to their final reward in the orchid heaven. I'm like good old Joe Stalin, dissent is not tolerated. If they don't like what I'm dishing out, off with their heads.

Nick

Thanks, Nick, Arthur and others for your views. I'm aware that perhaps I have too many orchids with differing needs in my northern VT sunroom (soon to go out on the screen porch) but I'm stubbornly trying to learn what does well and also, I love the challenge of trying a difficult type. (I have a miltoniopsis that I try to water every other day after reading what Jane said about it.) Reid Kawamoto graciously offered his perspective on watering when I emailed him today and I will post his last statement here:

Yes, most pseudobulbs eventually dry up and there's really nothing you can do.

Hallelujah, that's what I was starting to think anyhow.

Miltoniopsis, Odontoglossums, Beallarea have similar culture: they like bright indirect light, but cooler temperatures with high humidity and good air circulation. Their medium is kept moist. but not wet. Generally, these plants are grown (in a greenhouse) with a swamp cooler blowing. Cattleyas, epidendrums, laelias are related: they prefer bright indirect light, but intermediate temperatures, and less watering. Moderate humidity. Paphiopedilums and Phalaenopsis like medium filtered light with high humidity and somewhat moist media: they can take more shade. All these different genus require specific cultural requirements. Not always a good idea to mix and match. Better to grow plants together that have similar cultural requirements. Cattleyas tolerate more light and heat. Cymbidiums require bright, almost direct light, but cool, moist feet. Dendrobiums like bright light like cattleyas, but a cool dormant period during the winter.

That is what i am missing, a greenhouse/glasshouse with a misting system or a swamp cooler. Seeing I have two glasshouses + the Shadehouse, there might be a bit of a domestic trouble if i suggested that i need another glasshouse. If i was Warren Buffet i would have a series of houses all linked so i could walk from one set of conditions to another merely by opening and closing doors.

Getting advice from people with glasshouses etc etc. doesn't really help indoor growers in Centrally heated homes in Climate Zones such as 4.

Maybe we could start with the Phalaenopsis and make a list pf orchids that are happy in the same conditions.

Only 3 houses? Any self respecting Aussie should have 4. When Senor Bryant, the $30,000,000 basketball player who was mentioned earlier was accused of rape (later cleared at trial) his wife had a divergent view of where their marriage was going to go. He bought her a $4,000,000 diamond thingi and her view came around to be in line with his.

Just ply your wife with something like that and she'll let you build your 4th house.

Nick

Didn't they call that the $4 million reminder? Every time Kobe's wife looks at her finger: "Oh yeah, you cheated on me". Five minutes later: "Mm-hmm, you cheated on me." Ten minutes later: "Oh right, you cheated on me."

He got off cheap, just ask Tiger Woods.