Repotting Catts

OK...here goes. I have read/heard that you should only repot Catts in growing season and they very much dislike being repotted when dormant. For me and maybe many of you, this means repot by end of August or wait until about March.

The confusion comes in when I also read to repot orchids after flowering. None of my Catts have flowered yet. 2 are in sheath but I understand that Catts can stay in sheath for MONTHS (spiteful little @#$% that they are) before blooming. The others are just growing bulbs and leaves. When is the right time to repot then?

And while we are at it.....most of my Catts started to grow p-bulbs in March or April. I assume that based on my growing conditions this means they will never bloom in the Spring or Summer. Out of a dozen Catts, could I possibly have ALL Fall/Winter bloomers?

Thanks!!

The best time to repot any sympodial is when new growth has just started to appear. The growth will emerge first, before any new roots, and if you repot then, the new root system will develop into fresh medium. That'll compensate for the inevitable (however slight) damage to the old root system that occurs when you repot.

That said, we've repoted Catts anytime from early spring till early fall (active growing season), but never when the sheaths are showing buds. If your sheaths are still flat and empty, you can repot (and even divide) with no harm to the plant or flowers as long as you keep at least 4 growths per division and the old root system is healthy and strong.

Bear in mind that any aerial roots which have developped will more than likely die when submerged in bark mix, so if you have a lot of those, wait until new growth develops from an eye and repot then.

As far as the "repot immediately after blooming" adage goes, that all depends on when during the growing season the plant bloomed. If it bloomed in spring, by all means repot: you know that new growth and roots will develop before winter. On the other hand, if the plant bloomed in fall, I would wait till new growth appeared the following spring before repotting: the plant will winter over in much healthier shape if its roots aren't disturbed.

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Louis J. Aszod

Thank you Louis that is tremendously helpful. The only part I didn't quite understand was the aerial root dying in new bark and emerging growth from an eye. I guess I only know "eye" in relation to dendrobiums. Could you explain that? Thank you!

Sure...

When you unpot your Catt, if you look closely at the rhizome you'll notice some tiny, upside down, teardrop or heart-shaped bulges at the bases of the pseudobulbs. Those are the plant's dormant "eyes" that will expand and eventually sprout new growth. Some will stay dormant, others will sprout. If you're dividing and you have a backbulb division of, say, three growths, as long as those growths have dormant "eyes" remaining on them which can sprout, that division will make a new plant. If, on the other hand, all of the eyes have already sprouted (or have been damaged so they can't sprout) that division will just eventually die, so you may as well toss it.

As far as roots go, epiphytic orchids are funny about those. If a root emerges underneath bark, grows upward and aerially for a while, then grows back down into bark by itself, the root will be fine. If it emerges and has grown underneath bark for a length of time, and you repot and leave that previously submerged root exposed to the air, it will more than likely die. Conversely, if a root has emerged aerially and has remained that way for a while, if, when you go to repot, you submerge that aerial root into bark, it will also more than likely die.

That's another reason why it's best to repot and bury the rhizome when new growth is just starting to show: the new roots will not only stay alive, but they'll go where you want them: into the pot.

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Louis J. Aszod

Well! Now I am thoroughly confused!
LOL!

I have two catts w/ a bazillion roots growing down and out. One was repotted in March, so I gather from this that I should just leave it be until after it re-blooms next Nov.(ish). Will that then be enough time so that those roots that have been growing out for so long won't suffer when I repot next year?

My second crazy rooted one is BS, purchased in Feb and started growing like mad soon after I got it. It has grown a huge new leaf and pbulb and the roots now have seemed to turn back down. Is this one that maybe should be repotted sooner than later? I think it may be on track to bloom sometime towards fall. Am I best leaving this one alone until after it blooms, since it hasn't bloomed before?

H, on the first plant you mentioned, the one you repotted in March, yes: leave it be until next year, when new growth is just starting to emerge. If you repot it immediately after it blooms in November, and you submerge those aerial roots under bark mix, you will risk destroying the entire root system that develloped aerially this year. If you wait to submerge those until next spring, the future root system that will develop next spring from new growth will take over to keep the plant healthy when the root system from this year (submerged now, right?) dies back.

On the second one you mentioned, where, if I understand you correctly, some roots have emerged aerially but have grown back down into the mix, you can repot any time during this growing season before buds have started to show in the sheaths.

If that still doesn't make sense, let me know and I'll go into more detail.

Also, for anyone who hasn't seen it already, I've done a step by step pictorial repotting guide with a cattleya in the CARE section of our site, here:

http://www.rv-orchidworks.com/cultiv...repotting.html
That might help clear things up also.

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Louis J. Aszod

Great! Thanks Louis, that makes sense, just wanted to be sure I was thinking along the correct lines. Excellent info, as always!

No prob at all.

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Louis J. Aszod

I believe the best time to repot is at the point where the new root nubbins first start to show up. On some that coincides with new growth, but others tend to produce the roots when the growth is near mature. That said, I pretty much repot whenever I want during the growing season.

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Jason

...And if that's been working for you, I don't see any reason to change. I only repot when the new growth first appears. I got into that habit when I first started growing after reading a post by Wilford Neptune, or some similarly awe-inspiring grower over at the AOS board. His philosophy seemed to be that it since it is critical for the orchid to go into winter with a healthy root system, the longer you wait after growth has begun, the more risk you take of the plant not being sufficiently established. That made sense to me at the time, so I stuck with it, but that's just what works for me under my specific conditions.