Selective overnight wilt on (dendrobium?) bulbs
 

Greetings, dear orchid lovers,

I write in complete despair - one of my beautiful plants (I am guessing it is a type of dendrobium, as I've never seen it bloom and the person who shared the plant with me doesn't know what it is )) went from gorgeous to monstered overnight.

As you can see in the photos, it wilted selectively, with a yellow tint, on a portion of a two-year-old cane, a budding new growth, a section of the oldest cane (from which all these growths began) as well as some roots (again, selectively, and only green tips of the roots).

I've had it for about a year and a half. Growth A is from last year, has just sent out some beautiful roots which seem to be unaffected at the moment. Growth B is from this year, it is just getting ready to send out new roots.

Conditions: grown indoors in medium to coarse bark, repotted about a week ago. Receives full morning sun, shaded afternoon sun. Watered when almost dry - although, I believe, I was constantly overwatering it for the first six months I had it.

About a month and a half ago I used KelpMax at three waterings, after that I have been using a dilute application of 30-5-10 fertilizer (@100ppm N, without pre-wetting the roots) at all following waterings.

Over the last month the plant also has received two applications of beneficial microorganism mix (Bacillus subtillis + others) and an application of Trichoderma natural fungucide last week - all at recommended prevention dosages.

I would greatly appreciate any comments on:

- what this might be - fungal, too much fertilizer, long-term overwatering, etc?
- as well as how to proceed - do I cut off deseased sections, treat with fungicide, do nothing, etc?

Thank you in advance to all participating in the discussion!

Possibly mildew is harming the roots and plant. If temperature is all ok ..... not too cold, then consider having gentle air movement in the growing area. The air can gently move around roots, media, stem and leaves, that can keep fungus, mold, mildew etc at bay.

The existing dark patches on roots. Just temporarily dry the roots, then maybe spray some mancozeb on the roots and stem etc. Repot into fresh lightly damp media.

Dear SouthPark, thank you for your response. I have all patio doors open during the day and windows slightly open at night, so there is plenty of air movement. I am just baffled as to what it actually is to move so rapidly - just yesterday there was not a sign of any problem (((

m.d. -------- hard to say what happened. But ..... clearly the new growth is very much alive and healthy.

So repot the orchid into fresh new media. I recommend an airy media ...... coarse bark, which is what you have been using.

You repotted a week ago into new coarse bark, right?

Was that new bark very dry? Very dry new bark actually takes a bit to become wet. So new bark needs to be pre-soaked a bit - maybe in warm water ------ in order to get it working properly. Otherwise dry bark repels water ..... and maybe your orchid just became dehydrated.

That newest plant looks just fine. And the old leaves don't look too bad as well.

Just repot into new media.

You mentioned that - in the last month, you've been applying various substances. Maybe it is too much - but hard to say right now, as there's not enough information ------ as in --- at the moment, there's uncertainty about the concentration of substances that were applied.

You mention constant over-watering. But the term 'over-watering' will depend on how much water is the media (and how much) ...... how watery, and for how long it remains watery or how long it remains dry. And how wet/dry the media is ---- at various depths of the pot. And how big the pot is, and what sort of pot it is (eg. how big and how many are the drainage holes).

At the moment, it looks like you dried the roots already (from the appearance of the roots in the photos). Is the orchid repotted now?

In that attached photo in the previous post - the blue circled region shows what appears to be a nice healthy plant. Need to look after that one. The other leaves actually look ok too .... from the old growth.

New orchid roots are growing from other old sections of roots too. So it appears that your orchid is still alive and well. You may be over-reacting ..... possibly.

But ------ if I were growing that particular orchid, I wouldn't bother putting all that extra substances into there. I would just provide weak fertiliser and weak mag-cal every now and again ------ and that would be about it.

In your case, since you have kelp max ...... I would just apply that every now and again. And if kelp max (which I haven't used, as we don't have it here in Australia) doesn't have mag-cal in it, then I would apply some weak mag-cal every now and again. My own fertilising schedule is less than most people I think. I just do once-a-month.

While my fertiliser application and mag-cal application is once-a-month ........ I'm pretty sure that the fertiliser etc stays somewhere in the media for a while ----- so that whenever I just water my media with water, there is still fertiliser/nutrients/elements that the roots can get. So it's not as if the orchid merely gets some fertiliser into it for just 1 day in a month.

Dear SouthPark,

Thank you so much for your time in this communication!

Because I have overwatered a few orchids in the past I might have been overly cautious and have, indeed, kept the plant too dry (and became very prone to panic when sudden things happen overnight )))))))...

I have taken note of all your suggestions and will tone down my watering-feeding routine, as well as have a closer look at the media.

Thank you again for your help!

m.d. .... you're most welcome.

Also, not that long ago, I purposely made a watering video ----- not for recommendations about watering -- but just showing what I do when I water my orchids. I find that if a pot is wide enough ..... this particular method works really well for various sorts of orchids.

Click Here (watering video link)

What are your temperatures? What kind of light is it getting? Did the stems receive direct sun as spring progresses? Could insects or snails be eating the roots?

Dear estación seca,

Temperatures are in the 24-27 range at the moment. It only receives full sun in the morning, until about 10:30 a.m., in the afternoon the plant is shaded. The plant is indoors, with many others, no sign of any creepy-crawlies.

---------- Post added at 09:25 AM ---------- Previous post was at 09:06 AM ----------

Oh, thank you for the video - I love to see "behind the scenes" from experienced growers! ))))

This particular guy is in a fairly low but wide plastic pot - which seems a perfect fit for your watering technique!! ))))

What I struggle with is the following: I grow without extra lights - just natural light from an east oriented lounge with glass doors on three sides, so very much dependent on sunlight. If I water heavily but the sun does not come out for the next day (or two, or three!) I feel like the plants are just soaking in the wet substrate (although, I only use medium to coarse bark)... I then switch on the fan to create additional gentle air movement to get the pots to start drying.... but I feel like I am miles away from striking the perfect balance between media water-retention/drying parameters ))

This is probably a Dendrobium nobile hybrid. I think the oldest cane might have sunburn. They need a large amount of water when making new growths, and do better if you never let them dry out. It won't root properly unless you pot it up right now. If you use something like fine to medium bark, or LECA, it will be happy with daily watering. Your plant has too few roots to support itself now. Not taking up enough water can cause everything you're seeing. Fortunately it is about to begin forming new roots.

This might be where my problem lies - I was basing my care regime thinking that dendrobiums like it on the dryer side :_( Oh, how much I still have to learn!

Thank you for your input, estación seca. I have returned the plant to medium bark - will keep my fingers crossed and continue to observe!

When I was starting out with orchids, I was told that nobile-type Dendrobiums should have no water from Halloween to Valentine's Day. When I followd wed that advice, they dessicated and a couple of them died. So I learned the hard way to temper the advice for my real-world climate. In nature, Den. nobile may get no rain for several months - but gets humidity and lots of morning dew. Where I live, along with only occasional rain, there's little dew... and in winter we may have days with single-digit humidity and summer-level heat! So I water them less in winter - maybe once a week if it's cool, more if we get those hot days. And they now are thriving. I think the cool winter nights are also a factor in blooming. I also don't fertilize them during the winter and that seems to help with spring blooming.

So... I learned through hard experience to temper the "generic advice" with some common sense based on observation. I think you have come to the same conclusion. New growth looks good, and you'll see more as spring progresses. Welcome to orchids!

Hi m.dlny,
It's a shame we don't know what variety of dendrobium it is, then we could tell if there really was a problem or not. I don't think there is much of a problem. Sometimes you ask a question on here and you end up thinking you have 10 more problems by the end than you really do. I mean this has happened to me before, I would not put it down to bad care or that something necessarily happened overnight (although usually too cold temps or too long dry period can cause something like this). It has started from one lonely backbulb so less than ideal conditions to start with.
Whatever the reason the plant is discarding the oldest growth first. The newest growth should hopefully remain fine.

As to getting the right conditions of the substrate - that is the bane of every orchid grower not just you. Nobody on here has figured that out yet and probably nobody ever will so you are not on your own, as you have discovered it is impossible to get it right unless every variable is kept constant (lighting, temperature, humidity). In winter plants drink less than in summer so ideally just like a car benefits from winter and summer tyres orchids could do with winter and summer substrates but that is not practical and would damage roots ;)
It's a constant monitoring and adjusting game. My biggest successes have been pot luck I would say, sometimes you get things spot on, other times you get things terribly wrong. Every orchid is different and there is no set procedure. I don't think anyone can say they get it right for every single orchid every single time.

So there should be a bit of perspective, you've kept it alive for 2 years from just one tiny weak cane. That is something not everyone can do.

Keeping an orchid dryier rather than wetter is the general advice because it is far easier to lose an orchid entirely by keeping it too wet. It might grow a bit slower if you keep it too dry but at least it will carry on growing without its roots rotting which is easily done if you are inexperienced watering so the advice is keep it dryer rather than wet. Once you get the hang of watering more and it sounds like you do well watching when it gets cloudy and use a fan to help the orchid dry out, then you can keep it a bit more humid at all times(just don't let it dry as much).

I would focus on the new growth, you can even cut the old canes away, they will most likely die now so if they have got any kind of bacterial infection, cutting them might be a good move but I don't want to give the wrong advice, I personally would watch it a bit more and if I was worried that the brown was spreading I would think about removing it.. Hope that helps. Every problem is unfortunately different and not easy to id from a picture, it might just be a case of old growth dying or it might be an infection so keep an eye on it - if it spreads , save the newest growth!

As a last note it sounds like it was growing fine for 2 whole years, you use kelpmax excessively and a bunch of other stuff I wouldn't waste my money on, you fertilizer is way out of balance, it should always be a balanced fertilizer and calcium is just as important as Nitrogen so if you want to do some good, don't experiment with experimental supplements until you know how much to feed of your regular fertilizer. That will do far more good than trying supplements which you will have no idea if they have been beneficial or not and whether to use them again or not in future.

Your fertilizer should be as balanced as possible, so something like 20-20-20 or anything close to that. I think mine is 20-10-20 but 30-10-10 is too much Nitrogen and thus if you do end up feeding the right amount of N, you will be feeding too little P and K.

Here are two good guides on watering:
A Guide To Feeding Orchids (Top 10 Tips)
Feed the orchids!: details of my fertilizer program for different genera

Good luck

The plant does look to me a lot like a nobile-type Dendrobium, or a close relative with similar needs. Generally, those don't want much fertilizer at any time... as you're headed into spring, whatever it says on the bottle use 1/2 or less. If I'm right about the type, too much nitrogen and you end up growing keikis (baby plants) instead of flowers. It is much better to under-fertllize than the opposite... too little fertilizer and it may grow more slowly but the plant won't be harmed. (Much easier to add than to remove...) Fertilizer won't cure a sick plant... think of it as "vitamins" rather than "food".

On Dendrobiums, I don't cut unless a cane is shriveled, brown, and crunchy. Some of these bloom on the old, leafless, even shriveled canes - and I have gotten flowers on canes that really looked dead, even over a couple of years. Cut the old cane and you may be cutting the part that blooms. I have had the experience of cutting something that looked dead, found it green on the inside... and uttered an expletive... but too late, you can't glue it back on. (There are some other genera that will do that to you as well, like Epidendrum and Barkeria. Learned the hard way...)

Roberta, thank you ))))

And you are absolutely correct! It seems I am finding out A LOT OF THINGS the hard way... It's a good thing I read in one of the treads on this site that to become an expert one has to kill 1,000 orchids.. or at least your own weight in plants - I must be well on the way to becoming one!!!! :rofl:

I have killed a lot more than 1000... and am far from an expert. The journey - the perpetual learning - is the fun part.

Dear Orchidtinkerer, thank you - your comments made me feel more at ease. I have decided to do precisely as you suggest - monitor it for a few days to see what comes and go from there.

As for the fertilizer... I've read quite a few articles recently about how bark-based substrate "eats" most of the nitrogen, so having higher numbers of nitrogen actually ensures orchids get some... And since I've struggled to find a balanced one (somehow most garden shops in SA keep very strange ratio fertilizers), I just went with what I got...

I am also aware of the Calcium and Magnesium requirement for orchids and would like to make my own fertilizer mix as per Ray's suggestions - adding Epsom salts and Calcium Nitrate to the fertilizer... but I am struggling to find the latter, so my feeding "mixture" is still evolving ))))

---------- Post added at 11:35 AM ---------- Previous post was at 11:31 AM ----------

Absolutely agree with the last statement )))

And thank you for sharing your thoughts in the previous post. When I had my first orchids, I was very "cut happy" but have also learned (the hard way!) that it is better to wait than to snip too soon ))))

hahaha .... M.D. ...... that was the old days. In these new days, where there is an abundance of information about growing orchids in general ------- it's certainly possible to cut down on the chances of killing general/mainstream orchids - such as tropical orchids.

I genuinely have lost a total of four orchids (cattleya). But this was a long time ago. I have really found that if certain basic conditions are satisfied, and provided we can deal with attackers (certain biting and sucking insects, and/or snails, rodents etc) and no bad virus gets in ------ then home-grown orchids can survive indefinitely ---- such as decades .... and more.

Experience certainly does help a lot. But understanding enough requirements, and maintaining those requirements is pretty much all that's needed to keep orchids going really well. And the information about the requirements can easily be gathered from sites - such as this forum.

Lots and lots of home orchid growers have orchids that just keep going and going (growing), and nothing bad ever happens to them ------ as satisfactory conditions are maintained.

For some places around the world - such as snow countries, where the temperature etc can be at levels outside of the orchid's safe range ----- then I can understand some reasons for orchid losses. But that's really due to life support systems not working (heaters etc) properly, or life support systems failing ----- loss of heating etc. But that is a control system problem ----- and maybe not much can be done about that, unless extra money is paid to have back-up systems.

I am very hopeful I will never get to the abovementioned level of expertise )))))))))

But also very glad that I found this forum - there is a wealth of knowledge here and I LOVE the fact that members are very engaging and supporting!!! And throughout my orchid research I've also come to realize that I far prefer to be selective in the sources I trust than drown in an ocean of conflicting information )))

One of the things I have found with regard to increasing one's success rate with experience... that certainly is the case. But for me, as a "What can I get away with?" backyard grower, the successes drive me to get more adventurous. So I push the envelope a bit further... sometimes I succeed, sometimes I don't , but I learn from the casualties - try again and often succeed the second time. When something (the familiar ones) get too easy, they become less interesting, when there are so many wonderful orchids out there to try - and to learn about.

My approach is ------ to read and find out in advance whether and orchid is able to grow and survive satisfactorily in my growing area. And to read and find out as much as I can in advance - about what can harm the health of orchids. Once everything is properly addressed ...... one can expect good results.

My approach is also - to look after and care for every single orchid - both small and large. My aim is not let any of them die. That is - not expendable.

This is different from say hybridisers, where they may treat orchids like grass or veges etc. Expendable - trashable, compostable. They have a different viewpoint of course.

My orchids that I get are not treated as hobby toys. They're my buddies.

But I also understand that other people have their own aims, interests, behaviour and ways of doing things etc. I can understand their side of things.

Dear Roberta,

Sorry for the delay - did not mean to ignore your comment )) I understand what you say - every type of orchid is like a completely fresh dialogue with a new creature... to me, anyway ))) And the challenge of working out the trick to make them grow at their best makes it all the more exciting!

---------- Post added at 02:45 PM ---------- Previous post was at 02:29 PM ----------

Dear SouthPark,

What you say is exactly the way I feel! Most of the orchids in my collection at the moment are "rescues" - I took them from people who did not want them (and could not be bothered to find out how to care for them!)... because, unfortunately, most people see them as a flower arrangement that lasts a few months - and then, rubbish bin!!!

I see "red"every time I am at a shop or a vendor who sells (expensive!) plants without roots, claiming "the plant is healthy because it has green leaves"...

I (am a nut!) and check on every plant every day - look for pests, check their roots, etc... And my goal in keeping them is their optimum growth, not one-season blossom...

As for learning about them in advance - I realize, I should ))) But I am too impulsive!!! I fall in love with an orchid and I bring it home - thus making my own life difficult by then having to bend over backwards in creating good conditions for them ))))))

M.D. ...... excellent words and excellent post.

Impulsive is ok hehehe. I have pretty much run out of growing space at home here, and there were a few recent times that I still 'had to' (against my own stone rock written rule) purchase an orchid hehehe. I can say at least (with an 'excuse') ----- circumstantial hehehe.

Totally agree with all that you mentioned - including the seeing red bit.

There are/were times when I saw orchids in supermarkets and other stores, that obviously were not watered, not tended to, not looked after. That was quite disgusting really.

Great to meet people like you on this board!

Thank you - the feeling is mutual! )))))