Roots rotting after transplanting

[GinaStarSeed]

Hi. I have over 40 orchids in semi hydroponics for about a year. I had them it plastic net pots with a tray underneath as a water reservoir. In the past year they have grown lots of healthy roots. So many that they went crazy and grew out of all the holes in the net pots. Then they become very hard to manage proper moisture. They start to look a little bit dry at times. So, to manage the roots better and increase humidity I moved them into a more closed plastic pot. Still has more holes than most Orchid pots, but obviously not like the airflow you get with a net pot. They have been in these for a couple of weeks and now many,many,many of roots seem to be rotting. Almost all are rotting totally or starting to rot at the tips. I unpotted one to check the inside and almost all the old roots have rotted. Should I move them back to net pots? Or just hope they will grow new roots and adapt to the new , constantly wet conditions with less airflow?? Please help!! Also, there is algae growing inside the pots. That didn't happen with the net pots. Is that going to cause problems?? Both the net pots and these pots both seem to have problems. The roots with the net pots grow very healthy but it is hard to control the humidity and hard to deal with the crazy growth through the net pots and these new pots seem to be too moist and are rotting all the roots? What are everyone's thoughts? Wait it out and let them readjust? And if that is the case, what to do about all the old rooting roots? UNpot them in a month or so and clean them out? and plant them back again? Thanks for your help.

[Ray]

You have changed the environment, so the roots have to be replaced. If they are failing, changing them back won't achieve anything but will add more stress to the plant.

What medium are you using?

[Leafmite]

What I have often done is just set the basket/net pots into a larger clear plastic pot, leaving enough room for good air-flow between the pots (often even more room is needed to fit the escaped roots). This helps to keep the humidity around the orchid while allowing plenty of airflow. The roots are not injured in the process so I do not need to worry about the roots getting infected.

[GinaStarSeed]

Originally Posted by Ray

You have changed the environment, so the roots have to be replaced. If they are failing, changing them back won't achieve anything but will add more stress to the plant.

What medium are you using?

All orchids are in clay pellets

---------- Post added at 01:40 PM ---------- Previous post was at 01:38 PM ----------

Originally Posted by Leafmite

What I have often done is just set the basket/net pots into a larger clear plastic pot, leaving enough room for good air-flow between the pots (often even more room is needed to fit the escaped roots). This helps to keep the humidity around the orchid while allowing plenty of airflow. The roots are not injured in the process so I do not need to worry about the roots getting infected.

This is a great idea.. too bad I repotted them all already. Also..what about when they outgrow even the outside pot? Do you just replant them in the netpot into another netpot? Ad inifitium for their whole life? Nesting the net pots inside each other as the plant grows ?or do you try to cut the pot off when you replant?

[Leafmite]

I drop the old pot into a larger pot. As the medium never decomposes and compacts, why not? The only disadvantage with not changing my medium is that I need to flush my pots very well periodically to keep my medium (red lava rock) from becoming toxic.

[Ray]

Originally Posted by GinaStarSeed

All orchids are in clay pellets

Growing in clay pellets in a mesh pot is not semi-hydroponics. The amount of evaporation that allows pretty much cancels out the wicking process. It's really just traditional culture in an inorganic medium.

Moving it into a less-porous pot is a move toward S/H culture, but really isn't there either, although the wicking has likely improved a bit anyway, and that's what changed enough to require the plants to grow new roots.

At this point, the best thing you can do is treat the plants with a good root-growth stimulant, and keep them in high humidity (to slow desiccation) while they get reestablished.

[tasha]

So we can plant phal orchids in net pots and leca balls? or no?

[Gil]

"Growing in clay pellets in a mesh pot is not semi-hydroponics. "

Well I guess this is another example of me not reading all the instructions thoroughly because I did the exact same thing. LOL on me! Looked and sounded like a good idea and my large Phal seems happy.
Soooo....think I'll leave that Phal as is, re-read the instructions and put a different Phal in the proper container for a try at S/H.

[Ray]

Originally Posted by tasha

So we can plant phal orchids in net pots and leca balls? or no?

Yes, you certainly can, but you need to be aware that doing so will require a LOT of watering, and that mineral buildup will be accelerated.

Hydroponics refers to growing in water. I coined the name "semi-hydroponics" to differentiate single-pot, passive hydroponics from systems using pumps, ebb & flow trays, etc., but the "water" part is still important.

My design of S/H pot uses any plastic container with a solid bottom and only two, 1/4" holes in the sidewall, close together, about an inch or so above the bottom. In such a pot, a reservoir of solution in the bottom is wicked up to the top, keeping the entire column of medium constantly moist.

When you water, you fill the pot quickly to the top and let it drain. Doing so 1) flushes the medium, 2) saturates it, and 3) refreshes the chemistry of-, and refills the reservoir.

The pot design has the added benefit of never being able to be overwatered, which allows automation of the watering.

The pot design can be simulated by using a solid wall pot sitting in a tray of solution, making it an external reservoir, rather than internal, as in my design. Net and perforated pots are unacceptable due to the evaporation from them outstripping the ability of the LECA to wick properly. Clay pots will also work, but only do that if you're attempting to grow cooler-growing plants, as the evaporative cooling from the pot walls will effectively chill the root zone.

If you want to actually learn more: Read This.

[Gil]

Well, soaked the hydroton last night, bought a 11/4 qt plastic container, drilled the two holes on the side and re-potted the large Phal that was in the net basket with only hydroton.
As dry as it gets here in the cool and cold seasons felt it was not worth having to water every two or three days. Even with the net basket inside it's solid plastic container felt it would still dry out quickly.