Help! Vanilla deteriorating rapidly

[Vanilla]

I've been growing a vanilla orchid for probably around 5 years. For the first year it didn't do a thing but then I gave it some artificial light and humidity and it started going crazy. I think it was probably about 7 feet long.
About a month ago I had to move it out of it's humidity tent and the tips were black where they had been touching the edge. It had happened once before and they had re-sprouted so I wasn't too worried. The tips fell off but now in several places along the stem it looks like cold damage (to me). The stem got darker and soft and then everything beyond that part dies rapidly.

I think it has been the perfect storm of neglect and I'm not sure what to do.

The potting mix has all decomposed so at this point it is quite compacted and not very airy. I'm not sure if this is part of the problem. I don't think it's been over-watered. I'm pretty careful about that. It's probably under-watered, if anything.

I haven't fertilized in a looong time and it's looking pretty yellow. I have thrown some worm casting and bunny poop into the pot occasionally.

It has been COLD and it hasn't been in it's tent. Well, cold for California standards. I keep it in a sunroom that is attached to the house, but it's not heated. I don't think it has actually frozen but the mornings have been 25 degrees for about 3 weeks straight. It is on a heating pad but the air is cold.

I suspect the cold has been the main culprit but I have no idea. I've never seen an orchid die so fast!

Two questions:

What can I do to help this poor vanilla plant?

If I cut off the parts beyond the damage in the stem, is there a way that I can root them?

Thank you SO much!!
I will try and get some pictures to help show the problem.

Leah

[Redcliffs]

I'm definitely no expert, but I do know its very easy to cut off any healthy portion and root it just fine. Three of my vanilla plants were started from small 2 inch cuttings, they were really an accident, my daughter ripped off a couple pieces. It took a year, but now they're each about 5 feet long.
So if all else fails you should be able to salvage some of the plant.
Trevor

[lepetitmartien]

Well, interesting case of frozen vanilla… It's definitely not the way to make ice-cream. I grow the same planifolia for about 30 years and did some of the same mistakes, fortunately, vanillas are very hard to kill provided the wrong condition doesn't last a year. So :

-3°C is way too low, Vanilla planifolia needs a minimum of 18°C (65°F), that's the first point.

At temperatures lower than 18°C, the roots are at stake, especially if wet somehow. A warm, growing, planifolia just love water and can live pretty wet in this condition. But its roots should dry up if the temperature/light goes down to protect the roots. Note that it's not a rest time, it's only that stalled growth periods that can occur when not under the tropics mean that the exchanges in the plant are of low volume and it can not pump/breath the water hence "save" its roots. In short : it grows => water, it grows not => let it dry between moderate watering.

The potting mix should be prone to decomposing, but the vanilla should not stay in a fully decomposed mix. It should be airy too. I don't know which one you use, but a mix for terrestrial eventually mixed with bark and perlite/LECA does wonders. Repot every 2 years, you can keep it longer in it but 5 years is too much a long time.

I have never had bits blackened but it can be fumagine with sap excreted infected by the fungi. Some sap/liquid can happen in the growing area. If it's powdery somehow and black it's fumagine. You can clean it (water), treat (fungicide) eventually, and if the plant itself is showing some signs of infections, you can cut just up the next knot.

What you should do:
- The soft aspect makes me think it may be some bacterial rot (does it stink? if yes, it is). Cut largely just up a knot, and clean the area with come hydrogen peroxyde 3%. Add cinnamon powder on the cut. Clean and disinfect your hands before proceding the followings.
- Depot, have a look on the roots if there's still some alive.
- cut every dead part left. If some bits of the liana is yellow, it's dying, cut (and cinnamon afterwards). Even if there's only a few knots left.
- repot what's left, if it's only a bit, respect the direction of growth, you'll save time. A large pot is not necessary, but one with a water tank can help in summer…
- keep it warm, more than 20° C (or better) and watch out for the rot.

My own experience with vanilla make me think that even if rotting, it stops at one time at a knot and the dead part dries out, but don't count on it, it's not hard science (yet).

I hope to have been extensive and that it'll save your vanilla. As we don't see it's current state I can't assure you it'll be safe, but vanilla are very strong, so there's a little hope. Now act promptly, as vanilla definitely don't like cold and rot of roots and twigs can go fast. Keep us updated.