cattleyas, dividing up big plants

[headbanger333]

Greetings from New Zealand! have tried splitting up two quite large cattleyas. I have cut the rhizome in two places, giving me my lead group of 3 pseudobulbs and two other groups of 3 bulbs. I have tried this before with no success. I pot up the lead group, putting the other two groups in a moist sphag bag. After 6 weeks, they are extremely wizened with no sign of any root growth whatsoever. Is there something else that I am not aware of that I should have put in the bag, or is regrowth just a matter of luck? Has anyone had much success with divided cattleyas becoming vibrant new growths? Thanks in advance.

[Subrosa]

It's always best to repot Cattleya just as the new roots start growing on the newest growths.

[katrina]

And no sphag bag. Pot up the divisions as you would a cattleya and the lead div will take off...the back divisions will eventually sprout new growths, if they have viable eyes. You will not see roots develops from old pbulbs...only the new growths that sprout.

If the older sections had no decent roots then those older pbulbs will shrivel up as the plant uses the energy to make the new growths. Timing is crucial, as Subrosa mentioned...if done at the correct time you will see faster progress.

[Orchid Whisperer]

The following has worked for me.

1. (Optional step). If you have keiki paste, try treating the "eyes" that are green, but not growing, a month or two before you plant to divide.

2. Every division that you make should have pseudobulbs in good condition, and should have one or more green eyes that are capable of forming new growth. 4 pseudobulbs (minimum) per division should be a goal. If old pseudobulbs (back bulbs) are in OK shape but have no viable eyes, it is best to leave the back bulbs attached to younger lead sections to provide energy and water.

3. Instead of sphag and bag, I prefer to divide in spring, when new growths are most common, and and hang bare-root divisions up somewhere outdoors in the shade, but exposed to air movement, rainfall, and water that you apply when watering other plants.

4. As an alternative to hanging them up, place the bare root divisions in empty terracotta pots, or tie them bare root to a piece of weathered cedar or other wood.

5. Whether you do No. 3 or 4 (above), new growth should appear in a month or two, followed by new roots. Pot or mount as you would any other Cattleya after roots start growing.

[headbanger333]

Thanku all, much appreciated. Us newbies need all the help available.

[estación seca]

Welcome to the Orchid Board!

Unfortunately, you did it going into fall. Your plant might not make new roots until next spring, if it survives. Lesson learned. Unless the old medium is in terrible shape, do not divide unless new roots are growing. Some plants I would leave even in bad medium because they so dislike repotting at the wrong time - like bifoliate Cattleyas.

Also, 3 pseudobulbs is about the smallest division with a good chance of surviving in most people's hands. I would not divide a 6-pseudobulb Cattleya. If you must for space reasons, and you aren't concerned with showing your plant, you could do it in two steps: first, cut, from the top down, half-way through the rhizome, at the planned division point. Let the plant stay in that pot until the newest pseudobulb, and the pseudobulb just behind the cut, are making roots, and swelling new growths. At this stage, remove from the old pot, complete the division and repot the two pieces.

[headbanger333]

Thank you for that, I was my own worst enemy by attempting it in Autumn. As you say...lesson learned. If there is not an eye on any of the old pseudobulbs, but it has good roots, is it still apointless exercise?

[estación seca]

There is almost certainly at least one dormant eye among those 3 pseudobulbs. If the plant doesn't dry up before it grows new roots it will live and grow.

[Regelian]

Another trick is to cut the rhizome while the plant is still potted and wait for the new eyes to develope. Then do the actually 'dividing' and potting. Of course, a cut rhizome could be a potential entry spot for fungi, therefore keep the plant dry until the wounds are dried. I do this in late Winter on larger plants and then wait for the new growth in Spring to re-pot.

[headbanger333]

Thanku so much, I am now realising how important it is that I do the right procedure in the right season!