Flasks (Project 15 - Spring 2013)

[shadytrake]

Hi Al,

Me too. I cooked 2 flasks thinking that I could "grow" the plants inside longer to get them bigger. $100 down the drain.

[orchidsarefun]

"[QUOTE=shadytrake;596874]
Second: The plants are not photosynthesizing so there is no need to put them anywhere near a bright light source while in flask. Just keep them inside at a normal temps on your kitchen counter (for a hobby flasker).
Third: When removed from flask, it is very important to let the plants get ready to photosynthesize."

its always good to get input from experts but on balance I don't agree with the extract above because by definition if you have seedlings with green leaves in a flask, photosynthesis is already taking place. Additionally photosynthesis mainly occurs in the leaves, not the roots. Exposing the flask to brighter light ( not heat ) definitely greens up the leaves and my seed propagator ensures that his flasks receive enough light to do so and grow the seedlings on. Further phals produce a phenol after too long in the flask that effectively poisons all the seedlings. I believe that is the main reason for deflasking sooner rather than later.

There may be other factors for following the process laid out, but imho its not due to a lack of photosynthesis.

[shadytrake]

Orchidsarefun,

I didn't say the roots photosynthesize. I said the plants have to get ready or at least that is what I meant. By hardening off the roots, you effectively stop the agar from being the food source. Then, the leaves (I said plant) start to photosynthesize, thereby becoming the food source.

I'm not scientific so I might be saying it wrong, but he was specific about the photosynthesis part. And he has over 50 years experience growing and breeding orchids.

[ALToronto]

Hi Melissa,

I agree with Orchidsarefun - there is definitely photosynthesis happening in the leaves of the seedlings while they're in the flasks. I think that if you kept the flasks in the dark, you might get germination, but you wouldn't get green plants four months later. So you must have misunderstood the expert you were talking to.

But yes, hardening off is important - it's probably why I'm having root rot problems now.

[shadytrake]

Originally Posted by ALToronto

Hi Melissa,

I agree with Orchidsarefun - there is definitely photosynthesis happening in the leaves of the seedlings while they're in the flasks. I think that if you kept the flasks in the dark, you might get germination, but you wouldn't get green plants four months later. So you must have misunderstood the expert you were talking to.

But yes, hardening off is important - it's probably why I'm having root rot problems now.

For sure I agree that it can't be in the dark. He was specifically referring to moving flasks to brighter light to induce more growth. Does that make sense? Maybe I'm describing it wrong.

[orchidsarefun]

Anyone have any views on when to transplant into individual 2 inch pots ?
I am thinking that a couple of mine are nearing that stage. The trays that they are in are almost 2 inches wide at the top and a pot will give more individual root space. ( deeper )
I think the moss has greened up because of fertiliser, I am holding off on fertilising - will only do so roughly every 6 weeks.

[billc]

They look like they are really doing well. Nice root growth. I don't when they should be moved, but they look the same size as some phal seedlngs I got last year from Olympic Orchids that were in individual 2" pots.

Bill

[ALToronto]

Orchidsarefun, I agree that that's a lot of algae on the moss. What are you feeding them, and how much? I'm keeping the N at 20 ppm for my seedlings, and mine are also 6 weeks out of flask, but the sphagnum isn't nearly as green.

A bit of algae is not harmful, but if the growth explodes, it will start stealing nitrogen from your orchids in order to sustain itself. At this point, if you stop fertilizing, you risk starving your seedlings.

This alone might be a good reason to repot your seedlings into fresh sphagnum, and continue watering with a reduced fertilizer concentration. I would put most of your plants into 2" net pots (not solid plastic).

[orchidsarefun]

Originally Posted by ALToronto

Orchidsarefun, I agree that that's a lot of algae on the moss. What are you feeding them, and how much? I'm keeping the N at 20 ppm for my seedlings, and mine are also 6 weeks out of flask, but the sphagnum isn't nearly as green.

A bit of algae is not harmful, but if the growth explodes, it will start stealing nitrogen from your orchids in order to sustain itself. At this point, if you stop fertilizing, you risk starving your seedlings.

This alone might be a good reason to repot your seedlings into fresh sphagnum, and continue watering with a reduced fertilizer concentration. I would put most of your plants into 2" net pots (not solid plastic).

I think I am going to repot some into 2 inch pots ( in sphag soaked in weak fertiliser solution ) and then hold off on the fertiliser on the others. If tray growth appears stunted I will have to make another plan. I have a good reference point for growth - 3 main leaves, as well as the size of the plants in the individual pots + of course, roots.

[Rowangreen]

Reading this I really must deflask my dend cyanocentrums! I would have done them about a month ago but decided to leave it until after the heatwave.

My phals are doing great though. All 9 still alive! Including the tiny ones.