I think I froze my cattleya. What do I do?

[BrassavolaStars]

Hello All,

In my area the weather is under unusual and extreme cold temperatures. This has not been good for the plants in my greenhouse. According to my monitors, it reached 37F in the coldest section of my greenhouse. The greenhouse on average was about 45F.

While the damage seemed superficial on most plants, it looks like this dowiana hybrid I have suffered some significant damage as the back bulbs on the red circled areas have turned mushy and black. It could be from something else, but I remember it looking fine a few days ago when I watered it and I think this kind of damage is consistent with the cold.

The other blue circled section are fine and have new eyes that are just starting to grow. What should I do? Should I unpot it and try to snip them off at the rhizome (divide it)? If I leave them will they just dry out? That seems to be what one of them already did. Should I leave it potted and just snip those off at the base?

This is a very unusual hybrid and I cannot believe I let this happen.

[K-Sci]

If the tissues didn't actually freeze, and this looks to be the case, the dark areas are almost certainly infected. Given that this is a dowiana hybrid, it most likely carries the notorious dowiana susceptibility to rapid collapse from infections. If it were mine, I'd do four things:

1) Cut off the infected parts such that 100% of the infection is removed.

2) Wipe down the entire plant with isopropyl alcohol or another disinfectant, and dust the cuts with a broad spectrum orchid-compatible fungicide such as Thiomyl or Banrot, or possibly a copper-based treatment. If you don't have a fugicide you could take a chance and use cinnamon, which will help dry the cuts and might possibly also help prevent infection.

3) If possible, treat the entire plant with a systemic fungicide such as Thiomyl (available at Amazon in the US).

4) If you have not already, move it to somewhere warm (well above 65F, and higher is better).

If Thiomyl isn't available today, you could use a copper based treatment such as is made by Ortho, which can be found in a store.

-Keith

[BrassavolaStars]

Originally Posted by K-Sci

If the tissues didn't actually freeze, and this looks to be the case, the dark areas are almost certainly infected. Given that this is a dowiana hybrid, it most likely carries the notorious dowiana susceptibility to rapid collapse from infections. If it were mine, I'd do four things:

1) Cut off the infected parts such that 100% of the infection is removed.

2) Wipe down the entire plant with isopropyl alcohol or another disinfectant, and dust the cuts with a broad spectrum orchid-compatible fungicide such as Thiomyl or Banrot, or possibly a copper-based treatment. If you don't have a fugicide you could take a chance and use cinnamon, which will help dry the cuts and might possibly also help prevent infection.

3) If possible, treat the entire plant with a systemic fungicide such as Thiomyl (available at Amazon in the US).

4) If you have not already, move it to somewhere warm (well above 65F, and higher is better).

If Thiomyl isn't available today, you could use a copper based treatment such as is made by Ortho, which can be found in a store.

-Keith

I do have Thiomyl in large quantities. I guess the bulbs are more or less tan and mushy rather than black. I was hoping that maybe they would dry up on their own and not spread to the other parts of the plant as that sometimes happens especially with dendrobiums I have had. It is around 48% dowiana though. I just was worried about being too aggressive with it and ending up making it worse.

[BrassavolaStars]

Alright. I amputated the bad parts and got clean rhizome, dusted with thiomyl, sprayed with physan and thiomyl, and am currently soaking a plastic mesh pot in physan and bleach (anti-virus measure as it is an older pot) to use. I did not have very many good roots left. I think it may have been going south longer than I realized possibly.

[K-Sci]

Originally Posted by BrassavolaStars

Alright. I amputated the bad parts and got clean rhizome, dusted with thiomyl, sprayed with physan and thiomyl, and am currently soaking a plastic mesh pot in physan and bleach (anti-virus measure as it is an older pot) to use. I did not have very many good roots left. I think it may have been going south longer than I realized possibly.

Perfect! Couldn't be better.

As you probably know, C. dowiana, as with most sympodial orchids, grows new roots almost exclusively from the rhizome of its new growth. If it were mine, I'd try to stimulate the new growth to begin ASAP using KepMax (and warmth if possible). This is just my preference and you may very reasonably disagree.

BTW, what is the hybrid?

-Keith

[BrassavolaStars]

Originally Posted by K-Sci

Perfect! Couldn't be better.

As you probably know, C. dowiana, as with most sympodial orchids, grows new roots almost exclusively from the rhizome of its new growth. If it were mine, I'd try to stimulate the new growth to begin ASAP using KepMax (and warmth if possible). This is just my preference and you may very reasonably disagree.

BTW, what is the hybrid?

-Keith

I just staked it with a wood skewer. I did borrow the stake from a zygopetalum I bought at trader joe's. Hopefully I will not spread any pathogens (namely viruses) that way. I have kelpmax and I will use that also.

---------- Post added at 10:59 PM ---------- Previous post was at 10:49 PM ----------

Meh. I just thought about it and switched the wood stake for a metal one i dunked in some comet. I'll sleep easier that way.

[K-Sci]

Originally Posted by BrassavolaStars

...I just thought about it and switched the wood stake for a metal one i dunked in some comet. I'll sleep easier that way.

Good luck! It would be great if you let us know how this eventually turns out.

-Keith