Best time to repot Oncidium

[PaulB]

I have an Oncidium, rescued about a year ago. It was in full bloom and did very well. It is still doing very well, with a very strong flower spike, about to bloom in a few weeks. Large, thick new aerial roots forming.

Here's the question: In pulling off the pot, there are a lot of dead and rotted roots, (which I've cut off, but haven't disturbed the main root ball) and the medium is most likely a fir bark, which is turning muddy and at the point where I would repot it, if it weren't for the vigorous growth and flower spike. Should I suspend repotting till after the flowers drop, or go for it and carefully give it a new, fresh medium? My feeling is that even tho it is doing well, the dirty diaper its living in will probably take its toll, one way or another.
I should have done it back in May or June, but wondering if August is still okay.

Any help is appreciated.

[Dendian]

Personally I would go for the careful repot. Soak well and then spray the roots off with water instead of trying to pull the pieces from the inside - less disturbance that way. You will probably find one or two areas with no roots to give you the holes to put new media in the center. I think you are right about the dirty diaper its living in now being future trouble - some rotten roots indicate something isn't right and wants to be changed. The new areal roots forming mean its a good time to repot anyway - new root growth can adapt more readily to new situations than the old roots can. Are you able to soak the aerial roots and then direct them downwards towards the pot?

[ARodney]

I agree with Dian. Change the dirty diaper

The plant may stall for a little, (key word may) but you and it will be happier in the future. On a preventative measure, sprinkle cinnamon in the roots before repotting.

Good luck.

[PaulB]

Thank you both! Since I posted about an hour or two ago, it's been driving me nuts. I pulled it and started the painstaking task of clipping dead and rotten roots, scraping out the mooshy medium (mooshy?)...only to find it is planted in a smaller pot! Geese! somebody just put it into a larger pot with more medium.
I'm finding that most of the roots are dead and some rotten, which indicates it has just been surviving on the aerial roots, not much more.

I'm in Southern California, so the temperatures are very nice right now. Warm, so I have misters around the area where the orchids grow and it works beautifully. The misters were put there to help cool off the house (and us) during the summers originally, but it works perfectly for the orchids as well.

We'll see how this all works out.

Thanks for the encouragement!

[Dendian]

Oh I would not put cinnamon on the roots - it will dry them out. If you have any Physan 20 you can use that. Only use cinnamon on cuts. I have stopped using cinnamon at all - I use the mixed Physan 20 in a spray bottle. I did not like how the cuts would dry up beyond where I cut, like it was sucking the cut area dry.

[PaulB]

Oh! I forgot, Adelia-

Cinnemon? Never tried it. Can you give a bit more info?? I haven't potted it yet..

[PaulB]

I normally use a quick Physan dip. This also helps disinfect any nasty things that grow in bad medium.
Still would like to know more about the cinnamon... whether good or bad. And why.

Thanks in advance

[ARodney]

Originally Posted by PaulB

Oh! I forgot, Adelia-

Cinnemon? Never tried it. Can you give a bit more info?? I haven't potted it yet..

Cinammon is a natural antifungal. Sometimes if the roots are mushy or have rotted, I will sprinkle some cinnamon to help as an antifungal agent. I do my own cinnamon spray where I boil some cinnamon sticks (make like a tea), then take a spray bottle, put a cinnamon stick in it, fill the bottle with the boiled cinnamon water, a little bit of baby shampoo and add water until the bottle is full. After I repot, I spray the plant down with the cinnamon tea. So far I have not have any negative results.

You can also use Physan. I read someplace it is good to use a antifungal just in case some of the good roots got hurt or to kill and fungi that may be in the old medium. If you use Physan, follow the directions on the label and use a spray bottle to apply.

Just remember, every orchid geek uses what works for them. I've learned what works for me. But them again it also has to do with the area the orchids are in and the micro climate.

Good luck

[Dendian]

Here is a really good thread on cinnamon:

Cinnamon is a desiccant

And you are right, Adelia, what doesn't work for me may work well for somebody else. I like the cinnamon tea idea - if I run out of Physan I may try it!

[PaulB]

Thanks for the info. I used the Physan, since I've been using it since the late 80's and have never had a problem. I usually dip the roots up to plant for a few seconds. I also use it to wash out new or used pots with it before re-potting and even tools I use around the orchids.
I read the thread on the cinnamon "tea" and that sounds worth a try! Fun to try new things and learn tips from other growers.

Have a great weekend!

[PaulB]

I suppose the bit of baby shampoo is to help the cinnamon tea be "wetter" or at least help it cling to the surface it is being sprayed on?

[ARodney]

Originally Posted by PaulB

I suppose the bit of baby shampoo is to help the cinnamon tea be "wetter" or at least help it cling to the surface it is being sprayed on?

I think the baby shampoo helps it work as an insectcidial. The soap allows for the insect skin (??) to soften or open and allows the cinnamon to penetrate to kill the bug. I read the information in a website, don't remember where and I decided to try it since it was cheaper than and safe than incecticide. I've been using it for about a year and do see a big difference. If I see the mealybugs I will add alcohol to it and spray everything down. Sometimes I would have to bring out the big guns and use bayers insect killer for roses. I just use this as an all in one.

[11Orchid126]

If you wind up with a large empty space in the root ball, don't use medium to fill it, as the medium will stay too wet with no roots to absorb the moisture and the roots will die. Instead fill the void with a few packing peanuts (not the disolving kind). The peanuts will stay dry and won't rot the roots.

[PaulB]

Good call on the packing peanuts. I use them all the time for other plants, besides orchids, tho I usually use them for my cymbidiums. Ya just gotta make sure they are not the kind that dissolve in water. Good way to find out is to lick them. Not a big lick, just a little lick.

[PaulB]

Geeze! I just found out I'm now a Junior Member! Cool!

I hate being a "newbie", especially when I am really an "oldie

[Dendian]

Keep talking/posting - its the way you change your title.... more posts - more stars, 'till they change color - then do cool things.. and you get to be senior - like me...

Oh, and I have an 87 year-old friend who tells me age is mind over matter - if you don't mind - it doesn't matter!

[PaulB]

Hey, Dendian-

It's now been a few days since I repotted the Oncidium. Your advice was well taken, tho I knew I needed to take care of the dead roots and the bad medium it was living in. I fully expected to look forward to some sort of shock: a slow down in root development or some type of stall. I know its only been a few days, but the roots are continuing their growth as if nothing ever happened. The flower spike is also continuing grow. Very cool.

I'm just sending this note to help encourage anyone who is dealing with the same issue(s) and to thank you and Adelia again for the advice and also the info on the cinnamon treatment and the cinnamon "tea".

Paul

[katrina]

Orchids are tougher than most people give them credit. It's not unusual to find a plant re-invigorated after a repot...especially if the old medium was stale and/or breaking down.

[PaulB]

I agree. Tho I have a lot of orchids, mostly cymbidiums, I've been taken away (about eight or nine years now) from watching them, taking the right care, feeding regularly, and just hanging out around them. Now, I do have the time, so I'm getting my "sea legs" back. Seems the older one gets, the more careful one gets. Funny how that works in other areas of a person's life.

You are correct. Orchids are much tougher than we think, and they are determined to survive, with or without you.

Thanks, Katrina!