Go back to bark if leaves wilting?
 

I recently changed over about 8 orchids, 6 phals and 2 paps. It's been about 3 weeks now I'd guess and none of them has really come back yet. One of the Paps never got the soft wilting leaves that the rest have but that one never seems to show what's going on.

Essentially all of them have the very soft flimsy leaves now, have for over a week, and now most are getting some wrinkles with one even getting a sliver of yellow in one of its main leaves. These are all in an office with huge south facing windows (although tinted about 800 - 1200ftcd at the plant) in Minnesota. It's pretty dry air coming on winter but also has very good air circulation. Most of them have multiple new roots, although most seem to be coming out above the Prime Agra and growing out over the top of them. A few are pointing down but don't seem to have grown very far. Based on the wilting leaves clearly it's not getting water. I've crushed some of the upper prime agra pellets and they don't seem to have any moisture inside, are they supposed to?

At some point on some of these should I give up and repot them back into bark and try again some other day or should I just stick it out and see what happens? If the old roots haven't died off is that a better idea?

Tutmos

I just move 2 phals, a catt, and a paph over about 3 weeks ago also. Mine seem to be ok. They showed no sign of stress. The prime agra does not really soak up the water. I am new to this, and these are my first to go S/H, but I believe it is just a surface wicking action . Did you soak your prime agra before potting them up? I soaked mine in a root stimulant for 24 hours before potting them up. Tony M.

Yes I soaked all of the prime agra in water with the rooting hormone for about 24 hours before potting them.

Hi Tutmos,
Welcone to the OB.:)

This is my experience with s/h.
I only fertilize (125ppm N) one month after transfer.

I have recently tried to feed some phals one week after transfer. A few days later some of the leaves have turned yellow/ red, now they have dropped off. I am watering with plain water again, they seem to be OK.

What is the concentration of your fertilizer?

It sounds like you are getting some new root growth, so I would leave it in s/h a bit longer and maybe stop fertlilizing for a few weeks until your orchids adjust to s/h.
The top layer of the Prime Agra can look dry, nothing to worry about, just make sure there is water in the reservoir.
BTW what is the humidity level in your growing area?

I am sure other more experienced s/h growers can also help with your orchids.

Stay tuned!

I just started the fertilized watering last week, the soft leaves etc. were well underway before that.

I'm using the MSU suggested for RO water, 2 heaping tsps in 1 1/2 gallons of water.

I'll give them a another week and see if any improve. I'm pretty certain I'll lose one Pap, it's already got a number of desicated leaves that crunch in the hand. Some are still soft and alive though so I'm still holding out a little hope.

Pretty low humidity and no way to fix it. The office has lots of airflow that's shared with 50,000 + other square feet. I also have a 120 gallon reef tank (150 gallons total system water) in the same office and that evaporates about 10 gallons of water a week, at least, during the winter and the air is still dry.

Did your orchids have new growth when you switched over to s/h?

Hi Tutmos and welcome to the board! I switched a few of my phals over to s/h at the beginning of the summer and the leaves started wilting and looking floppy at first. I just left them in the s/h and things are definately getting better. The fact that you are seeing good new roots is a good sign! One thing that really helped me is misting the top of the primeagra and the exposed roots. Within a few days the top most leaves started perking up and looked a lot better. I figure that the top is the first to dry out and if a lot of the roots are at the top then maybe they just need a little more moisure for awhile. :biggrin: Also try cutting back on the fertilizer a little. Right now it probably isn't doing your 'chids much good anyway and 2 teaspoon for 1-1/2 gallon seems like a little to much. I use 3/4 teaspoon for 1 gallon. Try cutting back or using nothing but rooting hormone for a little while. Good luck! :)

I have no idea how to achieve 125ppm N for MSU- we unfortunately don't have it here in Oz.
Someone please advise.

Hi Buds,
we don't have a supplier for MSU here either. i've used this to calculate my N levels:
http://www.firstrays.com/fertcalc.htm

i'm using hydroponic fertilizers that i've mixed as close as possible to the MSU concentration.

In reverse order - the simplest way to determine 125 ppm N is to divide 10 by the %N in the fertilizer, giving you the teaspoons per gallon to add. It's not dead-on, but neither is the calculator!

Going back to the original problem, I'd bet it was poor timing of the repotting coupled with a fairly drastic change in root zone environment.

• As roots grow, the cellular structure tailors itself to work best in the environment in which it's growing.
• Once they have grown, they do not change.
• When we move plants into a new - different - root environment, those cells will not perform their function as well.
• The degree of "disfunction" is dependent upon how disparate the old- and new environments are.
• Repotting a plant when it is actively growing new roots gives them the opportunity to tailor themselves and support the plant; the old roots may not be able to do so, and if there are no new roots coming, the plant will suffer as described.

The thing to do is NOT to repot again and stress the plant further. Instead, you need to reduce the stress it is experiencing:

Leaves shrivel because the plant is losing water faster than it can take it up - the less-than-ideally-tailored roots are not "cutting it", but the chemical processes in the leaves continue. In order to improve the balance, you need to slow the moisture loss through the leaves, and that's where the old, reliable, "sphag-'n'-bag" technique comes in.

Put the plants - pot and all - into a clear plastic bag and close it up. They are then in nice, cozy mini-greenhouses where the %RH will be maxed out, and the moisture-extraction driving force will be reduced, if not eliminated.

Keep the plants warm (I prefer a minimum of 70°) to accelerate their metabolism, and shady (to prevent "sphag-'n'-bag" from becoming "broil-in-bag"), and they should recover nicely.

A couple more things to consider:

• All those "bullet points" above apply to ALL repotting jobs, not just those involving moving them into semi-hydroponics.
• S/H-to-S/H repotting can be done at any time, as the new- and old conditions are identical, and as that usually means just moving the root mass-and-medium to a larger pot and adding more medium around it, the roots are undisturbed.
• The same is not true for any medium containing organic components that can decompose, as the old- and new conditions will never be the same, and you'll probably do some damage as you pry the old medium from the root mass.

Lastly - and I don't know if it applies in this specific case or not - quite often, folks will struggle with their plants, gradually weakening them due to the stresses of less-than-good overall culture, then move them into S/H culture in hopes that it is a "magic bullet" that will cure all ills.

It's not. It won't.

What they have unknowingly done is take an already stressed plant and applied a great deal more stress (for the reasons described above), so the decline accelerates, they blame it on S/H culture. Some think they will improve things by moving it back to more "normal" culture - which often kills the plant. Been there. Done that.