Repotting Culture

[Carper]

All,

It's a simple question but it would be interesting to know of growers methods and successes in the above.

The simple question is this. When I repot, I take the following steps:

I normally pot on. Some times the medium just falls away so I clean off any dead roots and gently replace the whole pot of medium. I use bark and a little perlite which has plenty of drainage. Sometimes I add a little sphagnum moss, but sometimes don't. I presently then only water very occasionally to dampen the medium. The mixture is RO water, with a very weak feed and something like KLN, superthrive and apply for about 4-6 weeks to try and encourage root development. Once I feel the plant is getting established I increase the feed strength gradually over a term of months until I am applying the same as to my other plants. I noticed from my last batch of repotting around July last year that this method, and by also keeping the plants a little drier than normal resulted in better development and establishment of the plants. It does work sometimes better with certain plants than others, but I feel it could be better.

Looking forward to growers methods and successes, but also any problems they may have encountered.

Gary
UK

 

[Rick]

Gary

I think you brought up something more long term and complex than our last years discusions of K'lite.

I switched a bunch of my slippers (paphs and phrags) over to baskets to avoid repotting. Several others are in SH which also don't get repotted.

Most of my non-slipper orchids are either in baskets or mounted (and don't get repotted).

When I kept more stuff in pots of bark or CHC media, repotting was based on plant appearance rather than routine schedule. But in some cases that could be as frequently as 2 x a year if the plants were doing crap.

At this time, I'm blaming most of the problems associated with the need to repot with potassium buildup. I have been potting up compots of newly deflasked seedlings in pots of bark or CHC based media and they are all doing very well compared to the old days (now using K lite at ~40ppm N weekly). I am using a kelp extract at low concentrations with the Klite, but I'm not playing around with KLN, ST or anything else anymore. Nor am I moderating my watering much for selected wetness/dryness over different months. I don't use straight RO anymore, but a 10% well water:RO mix to give me very soft/low TDS water (but not "pure" anymore). In my present experiences, the Klite program has become almost a "unifying" principal simplifying all the hundreds of little variables that affect my orchids.

I'm trying to simplify my life so that I don't have to make every new repotting event a new research project.

 

[Jim Toomey]

KISS method!

 

[Stone]

Gary, you are right in saying dryness stimulates new root initials. There have been quite a few studies that demonstrate this. When I repot, I water once to settle and flush the mix, then no more water until the mix is almost crispy dry, then repeat. It seems to work for me, although I do mist lightly and often.

 

[Carper]

Rick,

I take it you just give all your plants the same treatment then, seedlings or fully mature, just applying the k-lite. The paphs that you have which are still in pots, how often do you water and do the pots dry out fairly quickly. Do you have any problems with any root loss? I know everyones culture is different here but I'm trying to get a generalisation for comparison. I've discussed with you before that I'm happy with my culture and feeding conditions so this is just an area I thought I may be able to improve further. My other questions would be does repotting damage existing roots in any way or does the new medium stimulate the plant.

Gary
UK

Gary

I think you brought up something more long term and complex than our last years discusions of K'lite.

I switched a bunch of my slippers (paphs and phrags) over to baskets to avoid repotting. Several others are in SH which also don't get repotted.

Most of my non-slipper orchids are either in baskets or mounted (and don't get repotted).

When I kept more stuff in pots of bark or CHC media, repotting was based on plant appearance rather than routine schedule. But in some cases that could be as frequently as 2 x a year if the plants were doing crap.

At this time, I'm blaming most of the problems associated with the need to repot with potassium buildup. I have been potting up compots of newly deflasked seedlings in pots of bark or CHC based media and they are all doing very well compared to the old days (now using K lite at ~40ppm N weekly). I am using a kelp extract at low concentrations with the Klite, but I'm not playing around with KLN, ST or anything else anymore. Nor am I moderating my watering much for selected wetness/dryness over different months. I don't use straight RO anymore, but a 10% well water:RO mix to give me very soft/low TDS water (but not "pure" anymore). In my present experiences, the Klite program has become almost a "unifying" principal simplifying all the hundreds of little variables that affect my orchids.

I'm trying to simplify my life so that I don't have to make every new repotting event a new research project.

 

[emydura]

What you are doing is pretty much by the text book Gary. A Paph grower here does much the same thing. I personally pot them up and put them back with the rest of the plants and treat them like the rest. I'm not organised enough or have a big enough area to be treating them differently.

When I repot I now make sure I get rid of the old mix and separate the roots. I no longer simply pot up into a larger pot. I have rotted too many root systems doing that.

does the new medium stimulate the plant.

Gary
UK

Many people say that Paphs have a real spurt of growth after being repotted. I think the inference being that more oxygen at the roots results in better growth. But I wonder if it is more related to the fact that the new mix has no build up of K, hence freshly repotted plants can access Ca and Mg much better.

 

[labskaus]

I'm certainly less organized than anybody else here, and haven't found yet THE culture method for all my slippers. I've tried substrates where I could avoid repotting for a long period of time and noticed that many Paphs didn't like it anymore after a year. I'm back to frequent repotting. The other extreme is a professional grower I know who repots his Paphs every six month, for the reason of the growth burst David mentions. I lack the time to do that.
I observe good growth on most repotted Paphs and wonder if that is due to the new substrate or the fact that I repot mostly in spring when they start growing anyway.
I see good root growth in most freshly repotted Paphs. I treat them all the same, fertilizer-and water-wise. But, since fresh bark keeps less water than older bark, I might accidentily keep repotted plants dryer.

 

[NYEric]

Repot!?

 

[Rick]

The only thing I've been potting up in pots of bark or chc in the last year are seedlings. So I haven't "repotted" any adult plants in a few years now. In general if they look like they needed "repotting" I stuck them in a basket.

I fertilize once a week, but through water around (without feed) every day. The seedlings probably get some water thrown on them about every other day. Fresh CHC always looks dry to me on the top of the pot, but periodically I do pick up pots and assess weight and then add water to get a feel for how much water is getting sucked up (and they do feel obviously heavier after a good watering).

What seems like a general improvement since K lite, is that by pulling gently on the new plants, it seems like the root systems are deep enough and strong enough so the plant does not pull up or otherwise shift in the pot. That is kind of a new experience for my 10+ years of pot growing where the majority of plants always seemed a bit floppy in the pots.

 

[The Mutant]

So, being a newbie and all I've got NOTHING to add except tell you how I've dealt with the 13 Paphs I have.

I repotted all except four (the substrate looked so fresh it felt unnecessary) and none of them had a great root system. I put all of them in the same medium I use for my Phals, which is bark (but instead of medium grade, I used small grade)/perlite/sphagnum and added crushed oyster shells to those Paphs that are calcicolous, except in the case with my roebelenii where I re-used the limestone it had in its old substrate, also, I added no sphagnum. I've added some packing peanuts in the substrate to increase the airflow around the roots on most of my Paphs as well.

I've no idea whether I've potted correctly or not, maybe I've packed the medium too hard since I can lift my Paphs, those that I dare to, by holding them by their fans - pot and all (even when they've been watered recently). If I'm unlucky, I'll end up with severe cases of root rot...

The thing I've noticed so far with those I've had for the longest time, is that they started growing almost immediately after being repotted - they seem to respond much quicker than Phals that apparently need more time to mull things over before they decide that they liked being repotted after all.

Oh, and I give them tap water in which I add some seaweed extract and a low dosage of fertilizer. I'll see which of them like it and which don't. Oh, and I'm trying to figure the watering schedule out, haven't gotten the hang of it just yet I feel, but I use wooden skewers as an aid so now all I'll have to figure out is how moist the skewers should be before it's time to water them again.

 

[emydura]

many Paphs didn't like it anymore after a year. I'm back to frequent repotting. The other extreme is a professional grower I know who repots his Paphs every six month, for the reason of the growth burst David mentions. I lack the time to do that.
I observe good growth on most repotted Paphs and wonder if that is due to the new substrate or the fact that I repot mostly in spring when they start growing anyway.
I see good root growth in most freshly repotted Paphs. I treat them all the same, fertilizer-and water-wise. But, since fresh bark keeps less water than older bark, I might accidentily keep repotted plants dryer.

I find that my bark potting mix would barely have broken down, if at all, after a year. In fact potting mixes 3+ years old often look like they have just been repotted. It is why I think the plants stop growing because of the chemical makeup of the mix rather than the mix holding too much water. I do use a coarse mix with pebbles included. If you use a fine mix then this would be different as they do start to hold too much water over time and need to be repotted regularly.

 

[abax]

I repot every plant I get into unglazed clay orchid pots

to accommodate the size of the roots. I normally use Orchiata, charcoal, a bit of perlite and loosen up the mix
with hydroton. I found that all my orchids in pots like this
airy mix and definitely enjoy being out of plastic pots and
more air circulation around the roots. I fertilize with K-Lite
once a week and usually water once a week for the Paphs.
in pots. Perhaps because my greenhouse is so humid I just
don't understand how anyone grows anything in plastic.
Well, I can't anyway.

 

[Rick]

But I wonder if it is more related to the fact that the new mix has no build up of K, hence freshly repotted plants can access Ca and Mg much better.

And that's a rather simple chemical explanation for the phenomena. I could also be that high nitrogen use with K build up favors the development of pathogen species of bacteria in the mix rather than beneficial strains (that support root growth)?