Help! Persisting Mold in All repotted Phalaenopsis and Cattleya
 

Hello! I am a very new orchid grower. I have a couple of phal. and Cattleya. I am having mold problems in both.
The Phal. is an Equestris 100B, and it came as a very small plant in a 2.5" container. It was already in spike, which has grown quite nicely in the past 3 weeks. However, after i watered it for the first time, I notice white mold under the top root, just a day or two after I watered. So I panicked and repotted. It was originally in sphagnum moss, so I got some NZ sphagnum moss and re-potted it quite loosely. I did trim a couple of rotten roots and to disinfect, I dunked the roots in Hydrogen Peroxide, which I now know is very bad for roots. After i repotted it, it was good, until I next watered it. And again, the afternoon that I watered, mold developed again. So i repeated the process over, repotted, disinfected with hydrogen peroside, etc. And surprise, again, I have mold. So that's when I read about water culture, and thought maybe I need to let it air out side the potting mix. I soaked the roots in water for a day (which i read something is Semi-water culture), and of course the roots became COVERED with white mold. There were very few roots to begin with, as it is a very small plant. I'm sad to say it seemed to have come with healthy roots, and I've destroyed them all!
Please advise me on what to do. I am almost at the point of to giving up on this plant, but really really don't want to. I am currently airing it off right now. I have read about creating a small bag situation where the moisture encourages more roots to grow. Also, I am looking at KelpMax and would like to try to use it to encourage more root growth. I feel that the existing roots are now destroyed, should I trim those off first then try the bag method? If I don't trim, I feel that I should use some kind of disinfectant to clean the mold? I don't think I should use Kelpmax with the existing bad roots, please advise!

And it seems that it a repeated pattern with my Cattleya that I've repotted. I want to say it was the hydrogen peroxide? Since I used it on every plant. I repotted the Cattleya loosely with medium bark mix of perlite, lava, bark and coconut husk. It seems to dry out very fast, also in 3" container with a lot of air holes. I also run a small fan fairly close to the orchids. They are under a grow light as well. So I feel that I've done everything fairly ok, and really couldn't figure out what I've done wrong. I was afraid of watering too much, and feel that the Cattleyas were really dry before I watered. I used to water once a week, but dunking and soaking for half an hour. The pots seem to dry very quickly and the plants looked dehydrated (getting slightly more wrinkly pseudobulbs. So this week, i watered it twice, as the humidity is decreasing from around 50% to around 40% very quickly. I am in the middle of the east coast and have fairly dry winters. I am planning on getting a humidifier to help the aerial roots. It's aggravating to me that the aerial roots of new plants that have just arrived are plump and in great condition, after it's been with me a few weeks, they start to shrivel up, while the inside roots are molding. I am so envious of plant growers whose aerial roots are so plump and healthy.

For the Phal. I realized that things went south after I watered the first time, which I did by running distilled water through the medium (moss), so the next time I watered, I used a water can with a thin sprout and watered near the perimeter of the pot and used a limited amount of water, not even enough to run it through the media. I also have been fertilizing all the orchids with a 20-20-20 at 1/4 teaspoon per gallon, and using only water every 4th week.

Please advise me as to what I'm doing wrong and what else I can do. Thank you so much!

We all have to start somewhere - your experience sounds like all the things most people have done at some point.

If the root is going moldy it doesn't necessarily mean it is beyond saving but it most likely is a sign it is. If they are soggy when you sqeeze the roots then they need to be cut off.
Once they are cut off you need to tug on the ends of every root to make sure there aren't any that are loose.

If the plant is strong enough it will eventually produce more roots if it is kept humid enough.

The trick to growing orchids well is figuring out how to keep them humid at all times without them getting too wet. This is something that is impossible to teach over a forum but what you need to get right next. You need to understand what a wet root looks like vs a dry root which turns a silvery color. The roots can never be permanently wet. But they can also not be completely dry for too long either. I try to achieve a half dry state where half my roots are dry looking, half are wet. That is a good equilibrium and best way I can attempt to describe how to keep roots happy. I personally have never bothered to learn how to grow in moss which is an artform if you ask me. Get it too wet and adios plant, it won't dry out fast enough. If you can get the humidity level right in moss it can be ok as it has antibacterial properties and holds water for a long time but if you get it too wet which is easily done then it is hard to dry out again.

It sound like the Fan is just making things hard for you, I use fans as a last resort if I really need them due too high temperatures or too low humidity.

Most of my orchids do fine without a fan so don't just use a fan as standard if it is going to dry your orchids too much, use a fan when it is needed, know when to use a fan and when it might be doing harm by drying the plants too much. Most homes do not need a fan or even a humidifier for that matter. But that is a separate topic as I don't like using something if I can avoid it - I actually use several dehumidifiers around the house to keep humidity from building up too much. I have a few hundred plants, they transpire a lot.

As a last point I will mention that you are feeding far too much. Use 1/4 strength, not half and use it every 4th watering instead of on 3/4 of the time.

A sick orchid is far harder to look after than a healthy one so if you feel up to saving this one go for it but it might be easier starting with a new one and try to keep that one from losing all its roots.

OT has mentioned all the important things.

OT made a good point ----- air-flow when needed. If the growing conditions don't require it, and air-movement dries up the orchids real quick - then air-flow probably won't be a good thing, such as in locations near the Rocky Mountains .... or some real dry low humidity desert region.

If fungus or mold does happen to grow easily, then consider bath-room condition. If after a hot shower and the doors/windows are kept closed ---- then the walls are going to start getting black stuff on them real quick after a while. But opening windows and doors to dry things out quickly ----- can cut down on that kind of thing, or prevent it. Same with towels on a rack in a room that stays humid and no air-flow. Nasty stuff is going to grow on the towel unless it gets the air-flow and dry out in good time.

Check out some of these links that contain some details that could be useful to you later - mainly regarding taking care of roots of orchids.

Click Here and Click Here and Click Here and Click Here and Click Here and Click Here

One thing that could be killing root is that peroxide. Roots have microscopic hairs (lots of surface area) and the peroxide destroys them. It can take a long time for an orchid to recover from even one peroxide attack on the roots... to do it repeatedly is likely to kill it. I know there are plenty of YouTube videos that recommend it... don't fall for that! The solution to fungal problem is to let roots go through a natural wet-dry cycle. (For Phalaenopsis not completely dry, but gently damp) When watering, water well - let the water run through the pot, which pulls air into the root zone and flushes out junk. (Like, hold under faucet, then let drain) Then wait a few days, and repeat. If you're getting repeat fungal infections in multiple plants, it sounds like you are getting cross-contamination from something else. Finding the source may take a bit of detective work. Sharing water is a major no-no.

How often to water needs to be determined by observation, and awareness of the plant's needs. Cattleyas should dry out more between waterings than Phalaenopsis. Orchids in the Oncidium group, and Paphs, don't want to dry out at all.. So Catts should be potted in big bark or other coarse medium, Paphs and Oncidiums in small bark, Phals somewhere in between. Sphagnum has some benefits, but it can be tricky to get it right... for most new growers, bark is more forgiving.

I definitely follow what Roberta mentions about hydrogen peroxide. I won't put that substance on roots of orchids after having noticed that it really can set the plant right back. I haven't killed an orchid with it before ----- but notice that the orchid can do pretty much nothing for quite a long time after applying hydrogen peroxide on them ------ not for treating disease ----- it was on healthy roots and healthy plants. That was my 'observation' of it, a lot of observation on it. There was a time I purposely sprayed all incoming orchids, roots, stems, leaves and all with hydrogen peroxide - prior to potting. Took quite a while for the orchids to start doing something. But if I don't do that root treatment ----- generally much different behaviour. The orchids generally just keep doing their thing, and start growing right away in my good tropical conditions --- no stoppage ---- eg. roots sprouting, new shoots sprouting etc.

I also believe that hydrogen peroxide can kill roots of orchids.

With regard to roots that look bad, don't be in a hurry to cut. Even if the outer part of the root is rotted, the "core" can still, in a limited fashion, transmit water. (They're not great, but without some roots, the plant has no way to take up water) Also, those "stringy" old roots serve to stabilize the plant in the medium - very important that it be held firmly in place so that new roots have a chance to grow. If the plant wobbles, those very fragile little root tips can get damaged and stop growing.

Kelpmax can be very useful to kick-start new roots. At this point, don't worry about the fertilizer... fertilizer is "vitamins" not "food" and won't revive a sick plant. Get the plant on the road back to health first.

Plants growing in houses with lower humidity will never have bright, fresh, fat roots like those on plants grown in a humid greenhouse.

Mold grows on dead plant material, not living material. You need to figure out why the roots were dead.

I suspect you are underwatering your Cattleyas. Once a week in an open mix, with a fan on the plant, means they are probably underwatered. You noticed the wrinkled pseudobulbs. If the mix is very open, and the roots have plenty of air, you can water much more often. The admonition to let Cattleyas dry out completely between waterings applies more to people growing in very humid climates, or in very humid greenhouses. Growing in a low-humidity home, it is better not to let them go bone dry.

I really don't understand where that peroxide craze comes from, and why people refute simple science, in the name of "I've always been doing it".

I've been told I don't know sh*t because I said to someone on Reddit that peroxide wasn't the solution to their problem.

Amazing how some persons ask for help and insult you when you provide it.

A perfect example of why I don't post about orchids on Reddit, or only rarely on FaceBook. If I wanna be slapped in the face, I can easily do it myself.

I don't think the slap in the face phenomenon is exclusively linked to reddit or facebook. Seems to happen all over.

I'm back on this forum after a different forum got annoying. The annoying people come and go. I find it interesting how orchid growers "like" to disagree far too much though.

I just used some Hydrogen peroxide this morning to get rid of some mold. It does work fine without doing any damage but I dilute it.

What rubs me up the wrong way is laziness to find out any better and laziness to change existing practices. I see it on this forum all the time too.
At least if someone is being lazy I would appreciate them being honest about it, being lazy is fine but being lazy and claiming to be a good orchid grower just rubs me up the wrong way as growing orchids is something anyone can do, it just requires effort so for someone to come along and say they know best when putting in minimum effort - it just won't work and is basically "fake news". I have gotten annoyed with people like that.

I've also come across racists and I've been banned on a foreign forum for being foreign.

I know I prefer orchids, plants and animals in general to people, it's why I started growing orchids and I would guess it is similar with most other people, you need to be a little bit antisocial to grow orchids - or at least a lot of orchids so I understand there might be disagreements but I have seen too much disagreements from orchid growers, sometimes I have seen jealousy and also sheer boredom that has led to pointless arguments.

But this is going way off topic and could even cause an argument in itself which I hope it doesn't.

I do always have to ask myself "am I going to offend anyone with this post" as someone always seems to get offended about something these days

Thank you Everyone for such quick and enthusiastic responses! As for people in general liking to argue, unfortunately the internet has given us a chance to be more aggressive than we would normally be face to face since we are all hiding behind a mask of anonymity. In that note, I hope that I am able to give more positive energy back to you all for the responses and hope that you've all give me!

I have turned off my fan today, but have opened a window that is a bit far away so there's a bit of air movement! I will also dial down the fertilizer for the other healthier orchids. I will order Kelpmax to help the sick orchids grow more roots, and won't use fertilizer with them. Roots of the sick Equestris 100B are really wrinkled and dried out now, they have been airing out today. I still see the white mold residue stuck on the roots. At this point, my plan was to cut the sick roots, then pot it into airy bark mix in small pot and put it inside a plastic bag for humidity, and also to add KelpMax. Upon reading the above, I should NOT cut the sick/moldy roots? Won't that just contaminate my new potting mix?

Yes, I am mystified as to why everyone on Youtube is endorsing the use of peroxide. I wonder if it's like a conspiracy for new orchid growers, like me, to kill our orchids faster, then have to buy more, haha jk.

For the Cattleya's, I have 2 smaller plants in smaller pots (which I've repotted). They are the ones not doing too well. I thought they seemed too shriveled, so I watered them twice last week, HOWEVER, i was really sad to find blue/green mold spots on the center potting mix. I don't see any white mold on the roots, so far, but its a bit more inside and I can't see it very clearly. Granted these are plants that I've repotted and have sprayed peroxide on, but that was a few weeks ago (at least 3). And since they've been repotted, I've left them alone, other than watering and giving some fertilizer. I don't know if the mold was in there prior to watering twice/week (which I've only done last week). Given the above information, does it still seem like I'm not watering enough? It's so difficult to tell with so many varying factors and info adding into the equation.

For my other Cattleya that is, dare I say it, more healthy, I am trying to figure out the best water regime. I have stuck (gently) a bamboo stick into the potting mix near the middle of the pot, it's been in there since yesterday. I pulled it out to check the moisture, and it feels SLIGHTLY moist and a tiny bit cold. Should I water it? The pseudobulbs have some slight wrinkling since I've had it, for a month now. And the last time I watered was last Thur. So I thought it was getting a bit dehydrated and I should water it instead of once a week, maybe once every 4 or 5 days?

Sorry for my long post, not sure of posting etiquette. Should I split into several multiple posts instead of 1 long one?

Thank you everyone!

---------- Post added at 05:58 PM ---------- Previous post was at 05:51 PM ----------

Hello Orchidtinkerer, when you diluted the peroxide, how much water vs. peroxide. Did you dip it or spray it? If dipped, how long did you leave it in there?
I realize these might be pretty 'dumb' questions, but I seem to lack intuition when it comes to plants as some other people have. So if it's not explained to me, I seem to not get it intuitively ...
Thank you!

First of all, there are no "dumb questions" except maybe the unasked ones.

Honestly, I don't think that peroxide is even that great of a fungicide. There are some systemic fungicides that some on the forum use. I can't advise, since I don't use any of them - having not had the problem. Physan can kill algae, won't hurt the plants but also is purely a surface treatment. When I repot, I rinse roots off well, pull off what comes with a gentle tug (those are really done) but leave what doesn't. I also don't try to remove the stuck-on medium because preserving roots is more important than aesthetics. (It's all about roots...with good roots other problems pretty much take care of themselves) The rinsing (like under the faucet or hose) pretty removes what one doesn't want to carry over to the new environment. (Even a little liquid dish soap won't hurt, just rinse well after)

Of all the cultural factors, fertilizer is down at the bottom of the list... green plants make their own food, and since orchids grow very slowly (progress measured in months not days or weeks) they use any minerals very efficiently. Get the watering, medium, air circulation, temperature, light correct, THEN fertilizer can start to make a difference.

You really need to figure out where all that contamination is coming from - media, water, or??? Preventing problems is a whole lot easier than trying to cure them. So if you rinse off roots well, and pot into a medium that won't encourage it to come back (like bark, or inorganic if you go the semi-hydro route) you shouldn't need to treat for nasties.

Dehydration happens two ways... underwatering is obvious, but overwatering can do it too if the medium is soggy and airless and kills roots. (No roots, the plant will dehydrate because it has no way to take up water) So take a little longer view... the goal around the roots of any epiphytic orchid (most of them) is "humid air" - not soggy wet, but not dry either . So when you water, flush well - which pulls air into the root zone. As the medium dries a bit, water gets replaced by.... AIR.

How often to water is something you'll have to determine by observation, keeping that "humid air" goal in mind. If the medium is open and airy, it will dry out faster and then you need to water more frequently If it is open and airy enough, you can't overwater... the closer you can got to what a mounted plant experiences the better. Indoors, mounted plants are pretty hard to maintain so we use pots. But bottom line, they get lots and lots of air... and it is impossible to overwater a mounted plant. Fairly large bark mimics that. When they get just close to dry (not bone dry) it's time to water again. That could be anywhere from one day to 3 or 4 days depending on temperature and humidity.

If still moist, then you don't necessarily need to water it.

Cold is 'ok' ...... but up to a point. Some orchids won't handle 'relatively' cold and 'relatively' wet too well. That is - internal processing systems requiring roots etc to be at least at or above a particular temperature for satisfactory growth process operation. This doesn't necessarily mean an orchid can't handle relatively cold root conditions. It can depend on 'for how long' roots are cold and wet for.

This is good timing, as in a different thread, I wrote a fair a bit about watering when using a particular media that I generally use in the tropics over here. Some details could help you too maybe in the future. After a while, you will get a feel or understanding about when to water orchids without needing to stick something into the pot ----- since growers with lots and lots of orchids are not going to use a dip-stick for checking moisture content of each orchid. It becomes can become too time consuming ----- which is actually ok if one does have the time though.

On the other hand ---- if you have similar pots and similar potting mix ..... then using 1 single pot as a reference (control) could maybe allow you to get a rough idea about all the pots in the growing area.

If possible ----- estimate the temperature of roots and/or media inside the pot (not just during the days, but during the nights too). And if there is a breeze, also take into account that breeze plus cold temperature can mean even 'colder' temperature.

LINK to thread

What are the temperatures in your growing area, day/night? What kind of light are your plants getting?

Photos would be helpful.

Repot orchid with bad roots & boil mix with clay?
 

It took me a while to figure out how to attach photos. Here are a few pics of my regular set up. I have them on a shelf that is very airy with light directly on top. The current temp. is around 60s, but the light makes it 70 degrees. The humidity has dropped from 40 to 30s. I really feel that I need a humidifier. Since it's not too cold yet, we like to open the majority of our windows throughout the day, so currently, the plant room has the windows open and a slight breeze.

Each plant has it's own plastic container for watering, and I labeled all of them to keep from confusion and cross contamination. All the pots that used bark, I will soak the whole pot into water for at least 30 minutes. I use a mixture of rain water and distilled water. Whenever I have gathered rain water, I'll use it, when I've run out I use distilled water.

Even though all my repotted plants have mold (shameful ...), I don't think it's cross contamination. I've never
watered different plants with the same water before, each plant has always had it's own watering container and they soak separately. I wash all the used pots / trays with bathroom cleaner that has bleach. I wipe down my shears with alcohol. I really hope it's not contamination after all these preventative steps I've taken.

There is also a picture of my poor messed up Phal. Equestris 100B. You might see that there are the dried white residue of mold still on the dried roots. It has a couple of new roots that were on their way to coming out before I took it out of it's pot. From the look of this plant, does it look like it's got stem rot? Is that why it looks so black on the stem? I feel that stems aren't usually this colored. I wonder if that's what gave it mold the first time.

I'm really afraid to pot it up again with the roots as is, and I'm soooo tempted to cut off the bad ones, but I've refrained until someone else has seen these pictures and could advise on cut or not cut before repotting. Can anyone let me know, after looking at these pictures, should I just pot without any other measures (like disinfecting, cutting bad roots, etc)?

The potting mix that I have on hand is from Repotme.com. However, I'm a bit skeptical about it, it had a strong smell when it first arrive. But I've baked it and have stored it in an air tight container. It's a mix of small bark, lava, perlite and those clay bead things (can't remember what they are called all of a sudden). I've included a picture of the mix from the website as well.

I think I should boil it a bit, to moisten it up. My questions is, should I boil the clay beads? or will that make them melt?

Thank you!Attachment 148609

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Those roots in the first picture look seriously dehydrated,and rather rotten. I'd wash them off well (even with a bit of soapy water, then rinse well). Pot up in clean medium. (Those nasty old roots, well cleaned, will serve to anchor it firmly) Water only with flowing water, so nothing new gets in there. The leaves look pretty healthy, so odds are good that it will start some new roots.

Even if you're not sharing water, are you reusing it? Not good... anything that gets in stays in. Flowing water is far better - like under the faucet.

The mix looks good - fresh from the bag it should not need further treatment. Both temperature and humidity are on the low side for Phals, but temperature is adequate. You can compensate for the low humidity by more frequent watering - with clean, flowing water. That will give the roots the "humid air" that they want.

Hello Roberta, thank you for the quick response!! Definitely not sharing or re-using the water, after soaking one plant I dump the water. I soak it because it seems that the bark dry up too fast by just running water. How long do you run the water for? Soon, we might not be able to do that as the faucet water will be too cold. There's a lot of hype about using distilled or rain water, instead of tap water. Is there any truth to that?

If the faucet water is too cold, you could just add a bit from the hot water side to make it tepid. (There's nothing bad about what comes from the hot water tank). For the plants that I have inside, I just use a pump sprayer and squirt until the water runs out. (If you load up a watering can or pump sprayer and let it come up to room temperature that also solves the cold-water problem.) Will it dry out fast? Sure. So I just water more often... can be every other day or even every day. (Where I live, relatively low humidity is a fact of life) By allowing some drying out between waterings, you don't create an environment that encourages mold, etc. - that is a sure sign of being too wet for too long. And that flowing water flushes out the molds, fungi, etc. instead of creating a petri dish for them. Start clean, flush instead of soaking, and it will stay clean with no treatment.

For most orchids, tap water is just fine - Phaenopsis and most Catts are not fussy. There are some picky cloud-forest species that benefit from rain/RO/distilled water, but that's not what you are growing.

Now, obviously if you let water run through the pot, it has to go someplace, preferably not on the floor. Check out what I did when I was using the spare bedroom as a greenhouse... "egg crate", that open light-diffuser stuff that comes from Home Depot, works great. http://orchidcentral.org/GrowingAreas/indoor.jpg

70 F / 21C maximum is cold for a Phal. equestris. That will make it difficult to resuscitate this plant.

The Cattleya will tolerate these temperatures but not be extremely happy.

Those temperatures are fine for the Dendrobium, especially in winter. It appears to be a Den. nobile hybrid or related species.

If your temperatures are low, perhaps you might wish to consider a different potting method that would allow plenty of air to the roots. I live in Ohio and our summers can be cool and wet and our winters are cool so I had to find a way of potting my orchids that would compensate for the cooler temperatures. I use basket pots. My Phal bellina is in one of these pots with a good quality long-fibered Sphagnum moss and really loves the set up. The Cattleyas are in these pots with lava rock. The Paph is in one of these with charcoal, rock, and large perlite.

This is a freshly potted Cattleya's set up.

Here's the deal about growing orchids. It's sort of like raising children, training dogs, breaking horses. Everyone is going to give you a little bit different idea about the way to do it. And you can't do it all or your orchids won't thrive and your dog won't come when called. You have to look at your own environment, then figure out what works best for you within reason. There is no one size fits all.

After growing for awhile, you come to learn certain things that are fairly constant. These particular orchids like to be potted or mounted so their roots can breath or have air flow.

The Den and the Catt will be okay with 70F in the winter. I'm sure you will have a way in warmer months to bump up the temperature on the Catt.

The Phal equestris is a species, so will be less tolerant of not receiving what it requires. Growing at 70F is at the very low end of winter nighttime temperatures. Figure out how you're going to get it warmer. There are lots of ways to do that: seedling heat mat, coil up a small rope light and put under it boxed, etc. Ask if you need help with picking a way then choose one that works for you.

The equestris needs more humidity. It's a species, and is used to 70-80% humidity and higher temps. Get the humidifier and get it going. All three plants plus yourself will appreciate it. Or get a tall wide vase, throw a layer of that bark mix at bottom with water to top of mix, put the phal in there on top of something so it's not touching the mix and partially cover the top.

It appears you have three orchids, so taking each to the kitchen sink and letting water flow through shouldn't be much hassle. Watering through like that helps bring more airflow into the medium and down to the roots. Water like you mean it. Then feel the weight of the pot. When you lift it up, it's heavier. When it starts feeling lighter again, water again... that's one way.

The mix from Repot me is a good mix. Just pricey. I would soak it overnight prior to potting up your plants.

Get some Kelpmax, and use it once a month. Maybe for that Phal a couple of times in the first month.

Roberta, ES, anyone... is that a Den nobile? I only have one, so can't tell. If so, some words about Den nobile winter behavior/care would be helpful....

Seeing the phalaenopsis makes me think the mold you have been so frustrated with has been the result of the death and decomposition of the roots. There may be several things going on there, so let me describe some scenarios that might apply.

The “Number 1” thing orchid growers must learn is how to provide adequate water while maintaining adequate air flow to the roots. Unlike terrestrial plants that do their gas exchange through their leaves, epiphytic orchids have shifted much of that to their roots, an adaptation to conserve water.

The “watering and potting medium” connection relates to the size of the voids in the mix. When we water (drenching is better than soaking, in my opinion), most of the water pours right through. Some of it is immediately absorbed by the plant and the medium, but there is a third portion that’s critical - that held by surface tension in the void spaces. If those voids are small - too fine of a mix, or one that had gotten old and is decomposing and compressing - then water can fill them completely, cutting off air flow to the roots and suffocating them. (I am convinced that the myth that “orchids must dry out between waterings” is a misinterpretation of that. If you have a suffocating medium when watered, letting it dry out opens up the voids, letting the roots “breathe” again.). If the voids are large - usually from using a coarser mix - they cannot be blocked by water, so there is no problem.

Lastly is root system adaptation.

As roots grow, their entire cell morphology “tailors” itself to function optimally in that environment. Once they have grown, they cannot change. Move those roots to a different environment by repotting, and they are instantly sub-optimal and will start to fail. That’s why it is always best to repot a plant just as new roots are emerging; they will support the plant as the old roots fade away and decompose.

However, sometimes you just can’t wait, as the state of the current potting medium could threaten the life of the plant. In that case, go ahead and repot, then “baby” the plant until it recovers:

• Keep the plant very warm and shady. A heat mat under the pot can’t hurt.
• Invert a clear plastic bag over the plant and pot to trap the humidity. No roots means no water uptake, but the plant can still lose it through leaf transpiration.
• Keep the medium moist.

If you soak the plant in a KelpMax solution beforehand and water it with that solution, it’ll accelerate the process greatly, but it is not essential.

That does look like a nobile-type Den. Temperature is no problem for that one. This type of Dendrobium does like to be drier (and cooler) in winter. My experience is that in a dry environment, you do still need to give it some water. And in that basket it will dry out fast. So that one, maybe water maybe once or twice a week. But still water thoroughly. We're fighting a fungal problem so keeping the root zone clean is very important - even if the water during (relative) dormancy keeps it from blooming, getting the environment cleaned up is #1, #2, and #3. It is a high-light plant (near a window would be good, will get both light and a bit of a chill)

So, that one can go dry between waterings in winter but still benefits from water after it does so.

And most leaves fall off, which is not of concern, correct? I remember when I first had one, all the leaves fell off and I thought it was a goner and trashed it. :blushing:

Correct. And for those Dendrobiums, don't expect root growth until spring. And don't fertilize at all until spring when it shows signs of waking up. Basicallly, it should just sit there, probably until February-ish or thereabouts.

WW, Ray and Roberta pretty much mentioned all the execellent tips and points already.

Once a grower satisfies (pretty much permanently, and not just sometimes) conditions on a checklist, then the chance of issues like mold, fungus, mildrew, root drowning etc become small, or even eliminated. Naturally there are other things to watch out for too - such as insects/mites and maybe snails and things.

Somebody from another forum recently had a case of virus ----- but some things can be beyond our control, so just need to go with the flow, and still apply measures to minimise impacts from that sort of thing.

The orchid grower will usually need to assess their environment, and then see what they need to do to address holes and gaps that haven't been addressed. And of course, to have an understanding of the general growing requirements (temperature etc etc) of the orchids to be grown. Once done ----- it will be or can be smooth sailing for very very long periods of time. That's the goal ----- to achieve smooth sailing.

Nobile types don't need to be dried out to the point of dropping all their leaves. If they get a cool winter and are watered they will flower.

As new grower after reading all the experts above, I look at my growing phalsc onc. and zygos. and realize even in dry new mexico, I am doing ok. I lost one phal early in the year, and one of my oncs, is not doing well, but does have some short new roots, but otherwise my 25+ all look healthy and happy. Have one short stem on a mini phal and getting all of them ready for winter. of my two seedling vandas, one is doing will, the other is surviving. My yearly vanda is doing well with root soaks 15 min once or twice a day, other wise in a vase. I appreciate all of you oldies but goodies, oldies in experience anyway, and Orchid Board has given me great advice always. ty ty ty

early - it's members like you that mention how you've been going, and finding the information useful toward successful long term orchid growing ----- that makes this forum really good, aside from the good personalities and also the general nice running of this forum.

That's pretty much it ------ the ability of us people to gather the information and techniques, then filter, pick/choose what information and method could work nicely for our growing area. Eventually, with enough time and experience and getting things together nicely ------ great results come, such as in your case.

The way I always see things is ----- if all those thousands or hundreds of thousands or million orchids in orchid nurseries all do really well ----- and are grown with automated systems, such as sprinklers etc, then we can know that they're doing the right things ----- and we just have to know more or less what they're getting right, and achieve good growing conditions all the time in our own growing areas.

On this forum, there are mix of growers - such as those that run/ran orchid nurseries, and those that have been involved with orchids really long times, and people that are starting up and reporting on what is working nicely for them. All the information from everybody contributing is very nice. There will be times when we encounter approaches or aspects that we hadn't yet seen of heard of, that may be helpful. This is the power in pooling and sharing information and knowledge. A nicely run forum like OrchidBoard is really good for this.

Correct. What the need is cool and NO FERTILIZER , not “no water”.

Has anyone said anything about not watering? I thought my question was don't they drop leaves, and Roberta confirmed that and said don't fertilize.

This is confusing me. And it's my understanding nobiles do drop most or all leaves in winter... some of the more hybridized not so much.

Of the Den nobile type, they tend to drop some leaves but not all. It does depend on the hybrid. Just to confuse the picture some more... I have a Den. that I got at a society auction about 4 years ago, that turned out to be mis-labeled. Based on the tag, I had been growing it in the GH... warm and humid. Didn't dry it out at all. Then, just a few weeks ago it bloomed... looked a lot like the species Den. nobile - not what it said it was. It was lush, never lost a leaf, grew like a weed, and bloomed about 6 months later than a Den. nobile "should" ... but I contacted the vendor who had donated it, and based on the picture, diagnosis was Den. nobile. The hybrids grown in Hawai'i are often in bloom at "unnatural" times.

So...in short, it is a continuum, not absolute, very dependent on conditions. If they get cold and dry, they lose more leaves. They survive and bloom just fine under a wide range of conditions. What I HAVE found is that following the "no water between Halloween and Valentine's Day" advice is a good way to kill them... I water them a lot less in winter, but not zero. In a dry climate (little or no morning dew during the "dry season") that's just too severe.

I do think that night temperature drop helps the blooming, with or without water reduction. I go back to what I have observed at Andy's Orchids... mostly mounted orchids so they dry out fast. But the deciduous ones (and some of the Den species go completely deciduous) get watered with the rest of the population (but do get a night temperature drop) and bloom very well. So... anybody who thinks they have the one and only formula doesn't know what they are talking about.

Recall the Den nobile hybrids sold in flower have luxurious, full sets of spotless leaves on every cane. The growers water them all winter.

Growers manipulate temperatures to induce budding at any time desired. The commercial growing section of the Yamamato Dendrobiums Web page, now gone, explained this in detail. The Wayback Machine (archive.org) may have takenna snapshot.

I had never heard much about not watering in winter months. All I knew was when I first attempted growing a couple, they lost their leaves, I thought they were dead and pitched. And avoided dendrobium, period, for years.

I just looked upstairs and have two nobile dens. They get same treatment as everything else, and have bloomed for me. One loses most of its leaves every year, but keeps on chugging along. Somewhere along the line I just started growing dens again, but never paid attention to soft vs hard cane, etc.

My original main intent was to let a new grower not to be overly excited if his den started dropping leaves. :biggrin:

Thank you for the more specific details! I will get a plant heating pad for when it gets a big colder and I guess wrap up a little tent for the Phal. Equestris to create more humidity. Its great to know that it likes 70%-80% humidity, it's a bit harder to create in my area, but at least that's a goal I should aim for.

I have another small orchid that I need to repot, it's a Phal. Dragon Tree Eagle AM/AOS. It's roots look ok so far, and has much more roots than the Equestris. It came in spike and started to form the bud here, but had a case of bud blast, and the little bud has dried up. I feel that I should repot it, since it's also in a squashed pot of moss and the moss look to be full of green algae. Now that I will not be using hydrogen peroxide to disinfect the roots, should I use Physan 20? Are there better products to use to clean roots before I repot into new mix? I am terrified of having pests or snails staying on the roots, so I've put it off until I have time to consult you awesome people! I've attached a photo of it and the roots. The first photo is the bud it started to develope, and the last one is the bud blasting.
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Also, it is a dendrobium nobile, thank you Roberta for the advise on it. The grower I got it from said it is supposed to lose it's leaves in the fall, form the buds then bloom around early spring. She did mention that I should not water it until the canes look a bit shriveled. However I should've taken into consideration that she is from FL, where it's much more humid than my area. So I have noticed the aerial roots start to shrivel and dry. I have been watering it once every 3 weeks or so. I'll up the frequency to every week? I do spray the dried up roots with water a couple of times a week so they don't dry up completely.

OMG, I've finally finished writing this email, it's taken me 3 days ...

I don't think that you need to do anything to disinfect the Phal roots... just get it out of that soggy mess and into something fresh. Don't worry about getting every last fragment of the old moss, won't hurt anything. Rinse well under the faucet, that will get it clean enough. I don't even usually cut roots - if the outer part (the velamin) is rotten and comes off easily, remove that. But the stringy core, if firmly attached to the plant, will help to anchor it in the new mix. I like bark because it stays airy - Phal roots, like most epiphytic orchids, really want "humid air" rather than "wet". Once it can (mostly) dry out between waterings, the algae/fungal stuff will be discouraged naturally.

If you use that you will need to water more often because it will dry out fast. Or fresh sphagnum if you need to water less. But when you water, let it run through the pot which pulls air into the root zone, then let it drain so that it doesn't sit in water.

Just a quick update, I have been watering by showering the plants, and not soaking. The roots seem to be liking it so far. I do think they are drying a bit faster, which is great. I've started to mark down the dates that I water.

Also, I have another cattleya, which I had pretty much given up on. It had the same problem of mold. So I left it alone for a while, I checked up on it today and it seemed to be growing a new cane and new roots!!! So I gave it some water and set it under the grow light. Its been in quarantine, next to Northern window, which gets indirect but weak light throughout the day. Do you think to move it all of a sudden to a fairly strong grow light is too much? Should I move it incrementally, like 4 hours a day, then longer and longer?

Look at these little root nubbins, I can't believe this plant is so resilient, after all the challenges I gave it!

Thank you all for the methods, so far I feel fairly good. It hasn't been very long, but at least no failures so far!!

I would movenit under the grow light now if it won't cook. What kind of light is it? How hot is the area under the grow light?

I personally love Physan. It's a great everything-cide, and it won't hurt your plants if you needlessly apply it. It may not work if the problem you are having is something the Physan can't treat, but dosing it with Physan won't do any harm. And I think it's just a good thing to keep on hand for when you need it. I'd dose your plants with Physan just because you can. It may help. It may not help.But it won't hurt anything.

I'm glad to hear that about Physan! I wanted it to be on hand for when I repot, to use it.on the roots to disinfect and maybe get rid of unwanted pests, like snails. I know there are some roots that will need to be cut. I will try to keep as much as possible, but those that i cut need somewhat to be disinfected and cleaned right? I still feel uncomfortable leaving them.

Here is the light I have, it doesn't get too hot. I'm not sure about its specifics, not sure if this image will tell much. It was fairly chilly today so it was around 67 degrees under the light.