Miltassia pseudobulbs turning brown at base

[CJ Green]

Hi--

I just noticed two pseudobulbs on my Miltassia (Bratonia) are turning brown at the base. These are two older bulbs. There is another old bulb that turned yellow and soft, but it had no leaves and I wasn't worried about it--I figured it was just done. But these two still have leaves and now I'm really concerned. The brown parts still feel firm, not mushy. You can see in the photos they're close to the old yellow one.

What should I do--do I need to repot and cut these off? The plant has five spikes and I'd hate to lose those flowers but I'd much rather not lose the plant!

Background on care--I bought this plant a year ago and haven't repotted it yet. The medium seems fine, at least on top, not broken down. It looks like there is a layer of packing peanuts in the bottom of the pot. I don't water it a ton; if anything I underwater although now that the warmer weather and growth has started I'm watering more.

[Ray]

I would guess - AND THAT IS ALL IT IS - that you're seeing the beginnings of a basal rot of some sort, maybe pythium or phytophthora.

Cleary's, thiomyl, or Banrot would be my first go-to's, or Inocucor Garden Solution if you want to try a more organic approach.

[CJ Green]

Thanks, Ray. I was thinking maybe Rhizoctonia. I just ordered some Inocucor. This might be for the repotting thread, but I am really wondering if I should take it out of the pot, get rid of those pseudobulbs, treat it (soak it in a 1:50 solution), and repot it. I'm just not sure if it's a bad idea to repot while the plant has five spikes, two of which are in bud. On the other hand, maybe my first concern at this point is the plant, not the spikes.

[King_of_orchid_growing:)]

Remove from pot and get rid of the affected pseudobulbs first. Then, replace potting media with fresh media and cut back watering. If you know the temperature of your growing area, that'd also be great to note.

Looking at the potting media from the top, most people tend to think it is fine. It is not the top of the potting media that is of greatest concern, the majority of the roots do not always grow on the top of the potting medium. It is the bottom and central core, basically whatever is visually blocked by the pot that should be a bigger concern than just the top. Why? That's where the majority of the roots are growing. If you took it out of the pot, you'll probably be seeing why this rot took hold.

[CJ Green]

Thanks, Philip. I will definitely repot. What I'm struggling with is whether to repot now, with five spikes (two in bud) or to wait until I've enjoyed the flowers. On the one hand, this is a good-size plant, and the two affected pseudobulbs are not the ones that are sending up spikes--this will be the first year for me seeing all these flowers, which is a sight I hate to give up on. On the other hand I don't want the plant to die! But I can't find any information on risks of repotting orchids while in spike--aside from phals, which everyone says is fine to do. Do you (or anyone else reading) have any experience having to repot an orchid while it's in spike?

ETA: As for the temps. over the winter the temperatures were 55 to 65 and the humidity was 35 to 50. West window, but hardly any direct sunlight. I did not water it a lot. All my orchids are grown on windowsills and I put them outside over the summer--there are wide swings in temperature, humidity, and light throughout the year in this northern climate.

[Dollythehun]

I am certainly not as knowledge as Philip. If it we're mine, I would repot very carefully. I had an Oncidium that did a similar thing last year. ES walked me through the process of removing those pbulbs and the plant is now fine. He explained to me that that particular bacterium is just everywhere and it probably wasn't a cultural problem. You won't know how fussy this plant is until you see the recovery.

[King_of_orchid_growing:)]

The plant may not be getting enough light. You can get a flood lamp LED rated at about 6000 Kelvin with a cheap dome lamp to get enough light to the plant.

If the day temperatures get to be about 75 F to 85 F that'd be ideal.

I recommend repotting now. It'll take upwards of 2 - 3 weeks for you to see it in full bloom. By then, this orchid would be half dead, if not completely dead. That rot acts fast.

[Dollythehun]

I agree with Phillip, that's pushing the temperature a bit to low. My coldest nights are 65-68f. But if you have 5 spikes, the light can't be terrible.

[King_of_orchid_growing:)]

Didn't catch this earlier. The odds of losing the spikes on an Oncidium type of orchid during repotting tend to be higher because of how delicate the roots tend to be on the majority of them. Unless you're growing thick rooted Oncidiums such as Cyrtochilum, the roots will get damaged easily on the Oncs with thin roots and the risk of losing spikes during repotting increases. So, it is generally the same issue you'd be having with repotting Phals, (that's why no one says anything in reference to specific orchid groups). The name of the game is to not do massive damage to the root system. If you are able to manage to do extremely little damage to no damage to the roots during repotting, the spikes should stay intact.

I've had several different kinds of orchids shipped bare root while in bloom. Some of them continue flowering as if nothing happened. Some of them bloom but look beat up. Some of them drop their buds or flowers prematurely. It all depends on the amount of stress they are under. (Remember, flowers are the plant's sexy parts used for sexy things. )

Usually, rots are not very common on healthy orchids because the plant's immune system handles those problems well. As with us humans, if the plants are stressed, their immune systems drop in efficacy. That's when problems like yours seem to pop up rampantly. Yes, fungus and bacteria are everywhere, and unless we're living in a sterile bubble, they will always be. It is up to the plant's immune system to defend it from the pathogens. If the immune system drops for whatever reasons, the pathogens can take hold and do their damage. If the plant's immune system is working properly, rots are very rare problems.

By the way, if you live in a cooler part of the US, (like Vermont), Cyrthochilums are awesome. They are quite large though.

[dounoharm]

do you keep it in a cache pot? if so, put some gravel or wine corks in the bottom to keep room to breathe on the bottom....if you water and then put it right back in the cache pot, then it will still be draining some....

I would unpot it, and very gently separate the roots and push in some new media in there and whack off those browning bulbs.

have a look at the cut portian and make sure the rhizome is green....and I would spray the cuts and roots with some physan or photon if you have it....if you have some rooting powder, you can dust it with that, it has a small amount of disinfectant in it....