repotting questions

[novicej]

I have a few questions about repotting that I am unable to find answers. Hopefully some orchid experts could help me here. Thanks in advance!

So here are the Questions:
1. After cleaning up the old mix, no matter how careful I am, I always end up with a lot of broken roots with splitted velamens, a lot of time over half of them are broken (more so on ones with fine roots such as oncidium and less so on Phals or Cats). Now how should I deal with them? Should I bury them in new mix as is? Or remove the outer velamen and bury the "wires"? Or trim them (which means trimming a LOT of roots). Are the roots after the break point still meaningful?

2. Most repotting instructions tell you to repot when new roots are growing but less than half an inch long. However after my repotting the green tips on those new roots will turn brown (or white) in a couple of days and stop growing. Is this supposed to happen? I end up with a few very shot roots, although eventually a few newer roots will emerge from nothing.

3. For oncidiums I have a hard time leveling the whole thing because the older pseudobulbs grows new ones higher and higher. So I often end up with the bottom of the new pseudobulbs above the mix while half the old pesudobulbs are deep in the mix. Is that OK because I will end up with a lot of aerial roots for the new growth. What else can I do?

4. How to train new roots to grow into the mix? Or do I have to do that? Because it seems the barks on the top will block the roots from getting down and make them grow on top of the mix.

Thanks again! Any thoughts/discussions are welcome!

[Cym Ladye]

It sounds as if you are repotting Oncidiums and Phals.

There are some basic rules of thumb for most orchids in pots, but there are also some specific ones to keep in mind for each genera.

For Phals, remove all the rotten roots and cut where they are broken on good roots. Then "screw" all the roots into the pot and fill with mix around the roots. Tamp down firmly if you are using bark. You might also visit the Beginner forum and take a look at the thread at the top "The Phal abuse ends here". It is full of helpful hints on the successful growing of Phals.

CL

[WhiteRabbit]

You will always end up with some damaged roots when repotting. As for fine rooted types, anything bigger than fairly small bark pieces will be extremely difficult to extricate from the roots without breaking many. So, I do recommend a finer bark mix - shouldn't be excessively fine tho (I like Gubler's fine bark mix), or coconut husk chips mix. You can leave some old bark clinging to roots, so long as you have got most of it.

I've sometimes had that problem, with new root tips dying after repotting - the good news is that when the plant is in root growth mode, there will be more. You can definitely wait til the new roots are longer than 1/2" tho.

Many orchids do have that somewhat vertical growth habit, and some of the Onc alliance very much so! You can leave that new growth above the media a bit. I try to avoid burying old growth in the media, but have done it on occasion without any problems arising from it - could depend on your climate if it may become an issue or not. It's probably preferable to angle the plant somewhat, so that new growth is at least closer to the media, without burying older growth much.

Most roots will find their way into the media on their own.

[james mickelso]

This is a problem that confronts most new orchid growers. But with patience it is easy to get the old media out of the roots without breaking them. If you do break some of the roots, after you repot the orchid, don't water it for a day or two. It won't hurt the plant a bit. Let the broken or cut surfaces heal. Water entering the cut or broken tissue can cause rot or allow other nasty bacteria/fungus/virus into the plant. Peroxide is a good general disinfectant but letting the plant heal is the best way. When repotting I found that tweezers are your best friend along with patience. You can get different sizes and types of tweezers from HD, Lowes, or even an auto parts store.I can't stress patience enough grasshoppers. I think sphagnum moss is the worst. If you take out the sphagnum moss when it is dry it is an easier task. And another thing to remember is that a wet root is damaged more easily than a dry root because the wet root is plump or filled with water whereas a dry root is much more pliable. If there are roots that have grown attached to the inner sides of the pot, take a thin sharp knife and insert it between the root and the side of the pot and carefully, slowly separate it. I use a hacksaw blade that has been sharpened along one side. But when the roots are dry it is easier to get them unstuck. With a bark media I always tip the pot on it's side and gently roll it around until the plant falls out of the pot so I don't pull on the root ball. Root tips.....these are the most important part of the roots. That is where the root is growing. Be very careful and patient. If the media and root are stuck together, leave them that way. As long as you get out as much old media as you can without damaging the roots too much that is ok. I could go on a while but this should be good food for thought. Oh and oncids.....you can plant the old pbulbs down into the media so the newer pbulbs/growth buds don't have to send their roots a long way to get into the media. But most orchids can have their roots out of the media. It's ok for them to hang down a ways because this is how they grow in nature.

[Cym Ladye]

Just like fertilizers: you ask 10 different people you get 12 different answers. Take your choice and use what works best for you.