Paph hangianum seedling culture

[Murmur]

Purchased two seedlings about a year ago. One hangianum, one micranthum. Both have received identical care. Bright unfiltered south facing window, watered right before dryness. Typical living room conditions. Good air movement. The micranthum has been doing really well, growing rapidly. Meanwhile the hangianum has been very slow, growing some new leaves but they are very small, smaller than the ones they’re replacing. Anything I should be doing differently?

 

[mrhappyrotter]

Without being there and without more specific details about care and growing conditions, it's hard to say.

Certainly, P. hangianum seedlings tend to be very slow growing compared to many other commonly grown tropical slipper orchids, but if conditions are favorable, you should be seeing each new leaf developing slightly larger than the last (until the plant is mature).

One thing that might be an issue (hard to say) is that it's probably better to go shadier when they're young, and at a minimum, if you're growing the plant brighter than it had been previously, that could explain smaller leaves. Also, typical living room conditions for you and typical living room conditions for me could be completely different in terms of humidity and temperatures. Seedlings may do better for you with some additional heat, like from a seedling heat mat. They may also benefit from a nice, noticeable nocturnal temperature drop which most decidedly is not typical in the average climate controlled living room in much of the industrialized world.

Of course, photos might also be helpful. How are the roots, that's an important factor in the plant's health.

 

[Stone]

I made many mistakes in the start with hangianum - and everything else for that matter. If you have smaller leaves than before it is almost always because the plant has lost it's roots.
Seedlings are not like mature plants, they do best in warm conditions. Does not matter if they are cool growers. Even armeniacum does better with good heat. 20 to 30 night/day all year is fine.
I bought a flask of hangianum about 3 months ago and put them into 2 compots. I keep them under lights for 16 hours at 20 - 30C and they are moving well.( mid winter here) Small plants in individual small pots seem (for me) to grow at about half the speed of compots if they grow at all. If you have a lot of seedlings about the same size, I recommend you put them all together in a compot regardless of the species and into a nice fresh mix which you can water often. And use a fan on them 24/7. Humidity should be high always. Once they are growing well, you don't touch them until they are bursting out of the pot, then pot up individually. This is what I do now for all the species and even sanderianum does much better this way.

 

[Ozpaph]

I've moved to the same thinking. Its working exceptionally well with the multis. I still have some trouble with Maudiaes. Havent tried hangianum................killed the only 2 plants I've owned....

 

[Stone]

. I still have some trouble with Maudiaes.....

Have you tried say 10% chopped and screened sphag with the bark?

 

[Ozpaph]

ill try that, thanks

 

[BrucherT]

It’s a joke how slow my hangianum grows. I would never buy a seedling of this species again. My conditions are similar to yours, but I keep mine in a decorative terrarium (with open top) with monitored 70% daytime humidity (I use a tray and mist to bring it up). I don’t use bottom heat; guessing that would speed up growth some but when I look at photos from my stupid purchase 3 years ago, my tiny one-root seedling has actually tripled in size. Still tiny. I used RO pure until this spring, now I 50/50 it with aged tap. Liquid Jack’s 7-5-6, occasional KelpMax, occasional CalMag (which I do notice it enjoys). Watered about once a week, on sunny days.

 

[spujr]

Seedlings are not like mature plants, they do best in warm conditions. Does not matter if they are cool growers. Even armeniacum does better with good heat. 20 to 30 night/day all year is fine.
I bought a flask of hangianum about 3 months ago and put them into 2 compots. I keep them under lights for 16 hours at 20 - 30C and they are moving well.( mid winter here)

I heard some adult parvis like or even need a cool, dry winter rest. At which point do you know the plant is old enough to need this requirement?

I agree about keeping the seedlings close together for faster growth, I've noticed this with my hangianums.

I found bottom heat to be effective. Here is a picture of some larger plants separated from the compot a little while back. They are generally slow growing but I've found hangianums quite easy to de-flask.

 

[spujr]

Once they are growing well, you don't touch them until they are bursting out of the pot, then pot up individually. This is what I do now for all the species and even sanderianum does much better this way.

If it takes 2+ years for the seedlings to get this big does the bark-spagnum media hold up long enough to wait longer or do you think one might need to repot when plants are smaller?

 

[Stone]

If it takes 2+ years for the seedlings to get this big does the bark-spagnum media hold up long enough to wait longer or do you think one might need to repot when plants are smaller?

I tend to follow Tanaka's experiences. He mentions that 3 species in particular (from parvisepalum) love water and you never let them dry out. These are armeniacum, delenatii, and emersonii. He does not mention hangianum so at the moment I'm lumping it with these 3. My delenatiis and armeniacum are doing MUCH better now that I water more often. I only have 2 emersonii in the ''hot box'' and they are doing ok. Certainly better now that they get more water. Same for the hangianums. You have to experiment with the mix. Straight bark works for some but not for me. Even bark mixed with perlite or stones just does not last long enough. As it rots it takes the roots with it and I'm back to square one. The colour of the seedlings is also a good guide that you are on the right track. Yours do not look good. I would guess the roots are probably non-existent or very weak and if you don't do something soon you will probably slowly loose all of them. So, if you are going to water a lot you need a mix that dries out quickly and is well aerated. A very coarse mix does not work either. It dries out fast but there is nothing for the roots to work with. A constantly moist mix (one that hold moisture for a long time) just does not seem to work the same as a mix that dries rapidly and that you have to water a lot. This is my experience of course so it could be different for others. This year I have decided to largely do away with the bark and use tree fern fibre/charcoal/sphagnum/polystyrene/bark about 2 parts/1part/1part/1part/1/2part. And I add some kind of calcium carbonate for the limestone growers. (Just to stop the mix getting too acid)
I pot very loosely at the bottom of the pot and firmly around the base of the plant. You cannot do this with anything but a fibrous mix. Also I melt some vertical slits all around the pot sides. With good air, this arrangement dries out in about 1 or 2 days. I have a theory that the moss and tree fern fibres act as a wick to the outside atmosphere removing water faster than bark does even though it is ''finer''. You will have to experiment with mix that will suit your conditions and remember that it will take 12 months before you can judge it. But one things for certain, you should repot those seedlings into a much smaller pot (probably 1/4 the size of that one) into a fresh mix and try to get them back to a darker green which is what they should be. if you cant find tree fern, maybe try bark and polystyrene with some chopped and screened sphagnum with charcoal. The ''trick'' is a very small pot that dries out fast or a larger pot with plenty of holes in the sides.
I'm still experimenting. Some people just throw any plant into a pot of bark without much thought and have good success but not me!

 

[Stone]

I heard some adult parvis like or even need a cool, dry winter rest. At which point do you know the plant is old enough to need this requirement?

I would not worry about the cool treatment until they a close to flowering size.

 

[musa]

Very informative, Mike, thanks!
Some years ago I ruined hangianum and emmersonii young plants, always thought it's the high temp.

 

[valenzino]

in my experience hangianum grows better,as said in other comments,very warm,lot of water and intermediate light...is like growing Phalaenopsis bellina....

 

[pluckerup]

Hangys are slow and warm growing. That is why flasks cost a fortune.

 

[Phred]

Very good advice... I’ve used all kinds of containers for compots. I find that shallow works best. They do dry out faster but that’s what I want. Growth is directly related to how often you can water. This is not the same as how much water you medium will hold. As you know too much water in the medium will surely rot the roots off seedlings in a short time. I found some heavy duty seed starting trays at a greenhouse supply. They measure approximately 6” x4”x2.5”. They have plenty of drain holes (two levels). I put a piece of Egg Crate Light Diffuser in the bottom with a piece of plastic canvas on top of that. (Plastic canvas is used for crafts) This allows good air flow and prevents the bottom from staying wet while the top is dry. A compot set up like this has about 1 3/4” medium on top of the canvas. For me,in the house, I water every three days or so...

 

[Phred]

 

[Phred]

Potted from flask 3/21/18

 

[BrucherT]

View attachment 16012 Potted from flask 3/21/18

Wow these are straight out of flask??? They look humongous!

 

[Phred]

Lol... no they are a little over a year from flask (3/21/18)
Sorry also, the photo was as a reference showing how good seedlings grow for me in this type of compot. Theses seedlings are a (daoense x Sorcerers Love)

 

[spujr]

I tend to follow Tanaka's experiences. He mentions that 3 species in particular (from parvisepalum) love water and you never let them dry out. These are armeniacum, delenatii, and emersonii. He does not mention hangianum so at the moment I'm lumping it with these 3. My delenatiis and armeniacum are doing MUCH better now that I water more often. I only have 2 emersonii in the ''hot box'' and they are doing ok. Certainly better now that they get more water. Same for the hangianums. You have to experiment with the mix. Straight bark works for some but not for me. Even bark mixed with perlite or stones just does not last long enough. As it rots it takes the roots with it and I'm back to square one. The colour of the seedlings is also a good guide that you are on the right track. Yours do not look good. I would guess the roots are probably non-existent or very weak and if you don't do something soon you will probably slowly loose all of them. So, if you are going to water a lot you need a mix that dries out quickly and is well aerated. A very coarse mix does not work either. It dries out fast but there is nothing for the roots to work with. A constantly moist mix (one that hold moisture for a long time) just does not seem to work the same as a mix that dries rapidly and that you have to water a lot. This is my experience of course so it could be different for others. This year I have decided to largely do away with the bark and use tree fern fibre/charcoal/sphagnum/polystyrene/bark about 2 parts/1part/1part/1part/1/2part. And I add some kind of calcium carbonate for the limestone growers. (Just to stop the mix getting too acid)
I pot very loosely at the bottom of the pot and firmly around the base of the plant. You cannot do this with anything but a fibrous mix. Also I melt some vertical slits all around the pot sides. With good air, this arrangement dries out in about 1 or 2 days. I have a theory that the moss and tree fern fibres act as a wick to the outside atmosphere removing water faster than bark does even though it is ''finer''. You will have to experiment with mix that will suit your conditions and remember that it will take 12 months before you can judge it. But one things for certain, you should repot those seedlings into a much smaller pot (probably 1/4 the size of that one) into a fresh mix and try to get them back to a darker green which is what they should be. if you cant find tree fern, maybe try bark and polystyrene with some chopped and screened sphagnum with charcoal. The ''trick'' is a very small pot that dries out fast or a larger pot with plenty of holes in the sides.
I'm still experimenting. Some people just throw any plant into a pot of bark without much thought and have good success but not me!

I think the photo is misleading on the foliage color, maybe over exposure, the leaves are actually darker green than what they appear there. I do agree that they are in too big pot and spaced out too much but I believe since they are actively growing, repotting them in a smaller environment and closer together will do more harm than good at this stage. I'll keep a close eye on them and if I see the new leaves smaller than the older I will do something.

I have a second basket pot like the one I pictured and I am curious to try Phreds method to compare, so will do that.

Both are in a wooden basket surrounded by spagnum and in the middle the mix is for bark, clay pellets, spagnum, and charcoal (don't know the specific ratio). Between the air movement, bottom heat, and lighting I have to water daily. I do give them a lot of light, which might explain the medium green color. So far I am happy about their growth and looks.

I have a newer flask of hangs where I am trying s/h growing. It's too early to say how well it works but so far all seedlings are still alive.