Selective overnight wilt on (dendrobium?) bulbs

[estación seca]

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.

[m.dlny]

Originally Posted by estación seca

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!

[Roberta]

Originally Posted by m.dlny

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!

[Orchidtinkerer]

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

[Roberta]

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...)

[m.dlny]

Originally Posted by Roberta

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!

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!!!!

[Roberta]

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

[m.dlny]

Originally Posted by Orchidtinkerer

Hi m.dlny,
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

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 ----------

Originally Posted by Roberta

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

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 ))))

[SouthPark]

Originally Posted by m.dlny

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!!!!

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.

[m.dlny]

Originally Posted by SouthPark

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 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 )))