Miltassia pseudobulbs turning brown at base

[CJ Green]

Originally Posted by 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.

It does get cold, and those temps are upstairs where it's a bit warmer. My downstairs kitchen windowsill drops to under 50. But yes, I think aside from winter the light is fine--as spring arrives, the light increases and this plant and my oncidiums get direct sunlight for several hours in the afternoon; I sometimes shade them a bit because it's too bright. And I do put them outside in the summer where they get plenty of light.

---------- Post added at 01:50 PM ---------- Previous post was at 01:47 PM ----------

Thanks again, to all of you! OK, I will repot it very carefully and if the buds don't bloom, so be it. It's a great plant and I would hate to lose it. I'll post an update after...

[estación seca]

Your winter temperatures are probably fine.

Rot enters Oncidiums through the roots. Often most or all of the rhizome is dead before it's noticed. The problem is less-than-ideal conditions. Too hot and wet, and too dry are the commonest issues. I suspect your problem is related to too little water, or rotting medium suffocating roots.

I would unpot the plant now. It is at risk of dying unless you get rid of the rot. It's probably spread far into parts of the plant you think are healthy. Cut off browning pseudobulbs by cutting the rhizome, not the pseudobulb. Sanitize your clippers or knife between each cut. Keep cutting until you see no trace of brown. It is possible the plant is already a goner, or you might save only one or two pseudobulbs. Repot into fresh medium. If you have healthy pieces they should grow and be fine, since it's warming up.

[CJ Green]

So I repotted the plant this morning and...it didn't seem too bad. The pseudobulbs that were brown were just discolored on the surface; I cut into one and it looked normal inside. Aside from one old yellow leafless pseudobulb, there were no soft or mushy places anywhere.

The roots were in great shape and there were a ton; it was definitely on its way to being root bound, so from that perspective it was a good idea to repot. I removed all the old media I could, got rid of a very few roots, sprayed with hydrogen peroxide, removed 5 pseudobulbs down at the base (they were difficult to remove because the rhizome was very thick, strong, and woody), applied cinnamon to the cut areas, and repotted in an oncidium mix.

While repotting, I noticed a sixth spike starting up. So now I'll wait, fingers crossed, to see if the spikes develop normally. I'm trying to be dispassionate about this and just treat it as a learning experience!

[estación seca]

Good news.

I would recommend never using hydrogen peroxide on roots, not even sick roots. It damages roots. If you've ever gotten some in your eye, or on a cut, you would understand. If you have a healthy plant, it is not a good idea to treat it with any kind of preventive chemicals. That only selects out the worst microorganisms, resistant to whatever you just applied. Cinnamon is OK on cut areas only, not roots.

Also you didn't need to divide it unless you didn't want the plant to be that big. If you have the back bulb section, it will probably make new growth if you pot it up.

[CJ Green]

Oh, no. Here's hoping the plant is resilient enough to withstand the unnecessary surgery!

And I removed the pseudobulbs because I thought they were diseased, not to divide the plant--but as it turns out they were probably fine.

What a terrific learning experience.

[King_of_orchid_growing:)]

I have no reason to believe the removal of the pseudobulbs will be noticed unless the orchid doesn't have very many pseudobulbs.

I know you cut the pseudobulb to see what was going on inside, and you didn't see any bruising on the interior. Plus you provided the photo evidence for it, but I think you made the right move. That kind of bruising can start off on the exterior surface and is able to make its way inside. It doesn't necessarily always start from the inside going out. The earlier this problem is caught the more effectively controlled it is.

If the pseudobulb was about to start to die back due to old age, this is not usually the natural progression by which it transfers energy to the newer pseudobulbs. It usually starts by shriveling/wrinkling and then this eventually leads to drying out, it doesn't usually get discolored like that and then rot away.

I hope it is understood why I am saying the following when I mention it, but once you become more and more familiar with your orchid's habits, you can tell the differences between natural senescence and disease easier. You will just know.

(Disclaimer: I'm not implying nor am I expressly stating anyone's stupid when I say what I said above. Neither am I trying to be condescending to anyone. It can easily be misconstrued as such on the internet. If so, I apologize in advanced if it looks that way, but I currently can't think of any other way to put it.)

[CJ Green]

Thanks, Philip. I appreciate your perspective and I didn't take it as condescending at all. I think it's true that while technical knowledge is important, there's a bit of intuition that comes into play as well. I'm optimistic that this orchid will do well. It still has 8 healthy pseudobulbs, and now it has fresh media and will soon be outdoors for the summer.