Hi and welcome to the forum. Orchids are not so 'picky' once you know the basics. Most consider the phal one of the easiest to grow. Your phal might do better indoors. An east window or south window that has a sheer curtain or blind would work. The only problem with all the humidity is providing enough moving air, another requirement for orchids.

I grow my phals either in clay pellets or spag. With both of these I use a balanced fertilizer that doesn't contain urea. This type of plant food isn't easy to find. I don't even know the name of mine as some of us in our OS buy it in bulk and divide it. So mine is not in its original container. I do feed with every watering.

Misting will be enjoyable for you and while you're doing it you would notice immediately if you are having a pest problem. Orchids don't have many pests, but they do appear from time to time. Mist only the leaves and the aerial roots, not the petals, nor any other part of the bloom. The leaves don't mind being wet provided they completely dry by evening. I only mist in the a.m.. With your cooler weather, only mist when the temps will be warm.

Phals don't like to get completely dry, but don't want to be constantly wet either. I like growing in the 'see-thru' pots, then you can see the condensation inside the pot.

I hope this helps. This culture isn't rigid. After a while you'll find out what works best for you. Good luck with your plant and enjoy!!!

Sheila :)

You might consider using the skewer method of watering, which I find to be very helpful. Get some shishkabob skewers from the grocery store, trim one down and put it in your pot and keep it there. The next time you go to water, touch the skewer to your lip, cheek, back of the hand, and if it's wet, don't water. If it's almost dry, water.

With your humidity so very high there is no need to mist the plant at all. Misting the petals/blooms might breed fungus such as boytritis. As Sheila says, air circulation becomes extremely important with such high humidity.

You can feed weekly, weakly using 1/4 strength plant food, with the fourth watering being a good, plain water flush to prevent fertilizer salt build up. Or you can feed twice a month with 1/2 strength plant food, or even once a month with full strength plant food. Whatever is convenient for you, as long as you give the plain water flush periodically.

As far as the plant food is concerned, there are may good ones out there. Dyna-Grow, Jack's Classic, and the MSU formulas are all good. You might even consider rotating a couple of them. As Sheila also says, it will be fun to experiment to see what works for you.

I would grow them in the house, if you can. Your temps are cool and humidity too high. I think you could run into rot with those conditions. 100% humidity is never going to let those plants dry out.

Jane

Where in California are you? We have many climates. Phals will do fine without heat all summer until into the fall. My heater is off and I have been leaving the greenhouse open all the time now.

Really high humidity is not so much bad for orchids as it is good for fungus and mildew. If the humidity drops into the 60s at least once a day and there is good air circulation mildew won't develop.

Richardol, I am right next door in Vacaville. But I've been checking the weather and it's been calling for high 40's every night lately. I've kept the heater very low so it stays around 60F at night and warms naturally during daylight hours. Every night I have opened the door a little more to find the sweet spot for temps and humidity and since I learned not to mist at night, I'm sure that will help lower my nighttime humidity levels. During the day I get much better circulation and the humidity drops into the 60's.

Jane_ny, I don't really have a good spot in the house for orchids but I'm trying to lower my humidity levels in the greenhouse. Nighttime was the only time I had it too high so I'm not misting at night anymore and getting more ventilation.

Granniek & Orchid126, I found a food called Better-Gro that says no urea and has the AOS label so I guess that's good. I couldn't find the other brands suggested. It's a 20-14-13, not sure what that means. The directions say feed at every watering with one teaspoon per gallon. Do I still need to cut that tsp into 4ths or have they already compensated for that since they also say you can feed every 14-21 days with one tablespoon per gallon?

Thank you all for your help!

Hi. Phals are easy plants, but you do need to prevent certain common disasters of which crown rot is a major one.

Misting is not needed and can cause rots to start. These happen very fast, so take care with misting, especially in such high humidity. The culture notes at Robert Bedard Orchids is a good discussion of why phals are so susceptible to crown rots, and how to prevent it-- mostly by keeping air circulating. The link to that discussion is below.

After a couple of instances of rots on orchids, I quit misting altogether. My phals thrived all winter in a basement light room with humidity around 50% max, ranging down to about 30%, and no misting. Wetting the floor raises humidity right away.

I agree with richard, that such high humidity as you have in your greenhouse is a perfect environment for all sorts of bad stuff. You need a fan going in your greenhouse.

Cut the fertilizer to 1/4 for orchids. You won't get a different answer to your question here or anywhere else. The instructions on your fertilizer container are probably giving generic advice. Orchid roots are specialized to take in nutrients in minute amounts. For that reason, they are easily poisoned. Overfertilizing can kill a plant, a slow lingering death. Better to under than over.

You can easily find out what the 20-14-13 means, and you should, but you will have to cut it to 1/4 for orchids. You will get excellent growth from a 1/4 dilution.

Go to the Dyna-Grow website, and you can find out all about fertilizers.

Good luck.

Here is a link that might be useful: phal culture discussion

Hey moby dog....I'm over in West Sonoma County and grow a mixed bag of orchids in a small greenhouse. I too was concerned about high humidity overnight, ranging up to 98% but others advised me that wouldn't be a problem with a good clean gh, 24/7 fans and good air exchange.

My gh ran all last winter in those conditions and I had no mildew, fungus or rot issues at all. I DID do a complete wash down in the Fall but the gh was closed up much of time during the winter.

I do open the door once the outside temp rises above about 60 during the day for good fresh air exchange.

BTW. Even with a heater I only keep my gh at low of 53 degrees (average) on the coldest winter nights- some few dropped below 50 inside and the plants did fine. I'm only a beginning grower (have nothing exotic) but have good growth, spikes and blossoms on a mix of types in those conditions.

I recently heard a speaker at the local So County club with a commercial gh in Half Moon Bay who said he pulled the plug on his heaters years ago and his plants routinely go well at 40s at night. That is a radical concept in some circles, I mention it only to reinforce that unless you have some specific reason for 60s at night you might want to at least consider the upper 50s.

Steve

I would still be concerned about that 100% humidity and cold nights over a long time period. I chill my Phals down in fall and they've been as low as 40's. But I don't have that humidity level. You are in California and obviously your cold period is shorter than NY. I think it's important that people in cold climates realize this might work for you, but would be a disaster over a 5-month period for most.

Cold and high humidity will kill a Phal faster than almost anything else.

Just my opinion,
Jane

Phalaenopsis need a greenhouse/glasshouse set for them. Something like a minimum of 60F rising during the day to the mid 80's F., but nothing much over90F. Summer is coming.

As i've said many times here i've failed to grow them in my glasshouse because it is set for Cattleya/Tolumnia. SO....that is why my 40 or so Phal. collection are sitting on windowsills in the house.

Currently in this room (A late Autumn afternoon) It is 73F the humidity is 57% and the temperature will drop a bit over night but not as much as in the glasshouses down the backyard.

I agree with Jane. Cold and humidity will kill a Phal faster than almost anything else. That is exactly what happened last winter when i went OS and agisted out my Phal collection to a grower with a glasshouse. They got cold and wet. A few died, some suffered more than others.

You need a Phal expert to tell you what the optimum settings are for a glasshouse.

In my limited experience with Phals i think all this high humidity stuff is twaddle. I am down to watering once a week with no misting and the humidity gadget always comes up with readings of 40 to 50%. The Phals are fine , some of them even bloom. But, no doubt, they would be better in a glasshouse set to optimum conditions.

Arthur, I agree...twaddle, good word! Mine are growing in a SW window, practically zero humidity in winter and they bloom. Now with Spring in the air and humidity indoors about 30%, all are making leaves - more leaves, more flowers.
Phals like nice, cozy temps. Not too hot - not too cold. Give them a nice chill in the fall, and hope for lots of spikes.

Jane

Thank you all for the great info. Since the first post about this issue I have purchased a fan for the gh and figured out how wide to open the doors to keep the humidity down at night. It's been staying around 40-60% now and the 60 is only after I water the rest of my plants. I've added the shade to the top of the gh and the light never gets above 1500fc when measured next to my orchids. That has helped the high day temps too. Even though it seems to me that everything is dialed in, the petals on my first phal are wilting. The other phals are still blooming. One of my dendrobiums bloomed a new flower yesterday.

New question. I've heard many times on this forum and my ortho orchid book about spikes and cutting spikes. First is the spike the side shooting stem that will bud? And why would I cut that off? And how if I needed to? The ortho book doesn't seem to explain those things.

On watering. I have heard good things and bad things about tap and RO. Why not just mix them to get the best of both worlds? It seems like the RO would water down the bad stuff in the tap and the tap would provide the minerals the RO doesn't. I've been told to flood the pot when I water. Can I flood it with tap under the faucet and then add the RO with fertilizer mixed in? It seems like that would also prevent the salt buildup but I'm not sure if there are any problems with that method I'm not aware of.

Thanks again to everyone for your time and help.

Why would you cut a flowering stem? This is a never ending question. You will know when to do so and this will be when you think that a few flowers at the end of a long straggly stem are no longer things of beauty.
You can even get some of the ones that are stimulated by a warm up to grow a new spike twice a year, provided you are willing to go snip at an appropriate stage.
Re. the water, see if you can get an analysis of your water from the local water authority/utility and read past threads on this forum re water quality.

Thanks Arthurm. I got a water quality report and read the past articles on water quality. But I don't see how to analyze it. Do you or anyone know of a site that lists the different elements in tap water and what levels are acceptable for orchids?