How to divide old Cymbidiums?

[JanS]

I have a number of Cymbidiums, all descendants from a plant given to me some 15 years ago. They do pretty well, put out new growth each year and most just finished flowering, some with 2 flower spikes.

When they get too big for a reasonably sized pot, I divide them into two but have been leaving the old (but still live, leafless) bulbs attached. I have to say, this makes the plants not very appealing. I have been afraid to cut all the leafless bulbs off (that still have good live roots in many cases) for fear of cutting stored nutrition off from the two or so newest growths that would be left. Yet, Cyms for sale never seem to have any leafless bulbs...

I am interested in what the rest of you would do with my plants - photos of two typical ones are attached.

Thanks!

[silken]

I am interested to see what kind of answers you get. At least yours seem to have most of the old leafless ones all in one area. Mine seem to be everywhere so its not just a case of cutting off a big old chunk of the plant. It would mean cutting it into numerous pieces of green leafy ones to remove all the old ugly ones.

When you divide an orchid you usually should leave at least 4 mature pseudobulbs in order for it to bloom again next season.

[Paul Mc]

Oops! LOL... I just repotted mine and as I had never removed the old medium it came in from the supplier I was rather rough with it. Needless to say, two pieces fell off of a larger one. Luckily, the larger piece had about 5 pbulbs on it. However, the roots were in terrible shape, many were dead, dried or torn. Guess I'll be giving it some rooting hormone with it's watering now as well. Good to know that I shouldn't expect it to bloom unless there are about 4 mature pseudobulbs on it though.

[Cym Ladye]

Jan,

"How to Divide my Cymbidium" is probably the most often asked question on the Cymbidium Alliance section of this Forum. See what you can find on threads posted on "Dividing Cymbidiums" on the Forum Menu (Top of the page) under "Search" for a start.

To answer your questions specifically, you need leave only one back bulb (BB), the term for a leafless pseudobulb, on a division. Remove the roots from it however, as they will eventually die and rot and take up space where it is better to have new roots. Also carefully remove the old dead bracts to make a nicer looking plant and to remove any critters that may be lurking there.

Leave 3-5 green bulbs but cut about 1/4 to 1/3 of the roots off so they will not touch the bottom of the pot and will be encouraged to branch and provide nutrition to the plant.

I have led a hands-on re-potting workshop for orchid club members for 20 years and have a hand out I have written and which was published last year in the CSA Journal. If you will send me your email privately, I will send one to you. Several of the Cymbidium Forum members have contacted me and said it was a BIG help.

Good luck,
Cym Lady

[JanS]

Originally Posted by Cym Ladye

Jan,

"How to Divide my Cymbidium" is probably the most often asked question on the Cymbidium Alliance section of this Forum.
Cym Lady

Sorry, didn't mean to appear like a complete dork - I did indeed look some stuff up on this forum as well as the rest of the net before starting this post. The trouble is most of the examples have Cyms that seem to have very few leafless bulbs and many leafy bulbs. One YouTube video shows a (pro) person splitting a very root-bound plant into two that has NO leafless bulbs at all!

My problem, same as Silken's post above, is that I end up with about the same number of leafy and nonleaf bulbs in the pot, and on some of them the leafy ones are dispersed among the old, ugly ones. So to divide them up so that I have only one old one may mean in some cases to be left with a leafy/old bulb pair only.

Perhaps the real question I should have asked is why do my Cyms not retain their leaves on the older growths longer? I do keep them outside and with the dry air in SoCal they do tend to dry out quick. Perhaps putting some water retaining components to the planting mix would help (I don't have enough space for all of them in my small greenhouse).

I'll get you my e-mail for the leaflet instructions - very generous of your expertise.

[Cym Ladye]

<<Perhaps the real question I should have asked is why do my Cyms not retain their leaves on the older growths longer? I do keep them outside and with the dry air in SoCal they do tend to dry out quick. Perhaps putting some water retaining components to the planting mix would help .....>>

Jan,

There are several reasons why your green bulbs are converting to BBs sooner than they should:
1) The plants are under stress because they are not getting enough water. In that case, the bulbs cannot sustain the leaves and support the new growths too.
2) If the roots rot from too much water, the same stress occurs as the roots break down and cannot carry food/water to the plant.
3) If the mix breaks down and the roots rot, the same stress occurs.

I feel that the mix you are using is too open and fast draining for your So Cal environment, as you also suspect. I would re-pot using small and/or medium CHC, coir and expanded perlite at a ratio of 4-1-1.

In the meantime, I would suggest you invest in some inexpensive plastic saucers and place them under each Cym. When you water/fertilize, the excess water will run through the pot, puddle in the saucer and the plants should absorb the water within 2-3 days. If water remains after that tip it out until you next water.

Some Australian growers swear by this method all year but in my cooler, Nor Cal environment, it has not been that successful except for a few plants. I feel it might be an answer for you during the summer and fall however, until you have a chance to re-pot your plants.

Good luck,

CL

[JanS]

Well, "Cym Lady" sure gave me (us?) much info! My case is definitely her Option 1 - keeping the plants too dry. I'm repotting them all tomorrow. I've had no perlite in the mix and on some days noticed the pots to dry out literally overnight.

Thanks!

[Shiffdaddy]

Maybe i'm wrong, but according to my "soils and fertilizers" class i took last semester perlite does not help retain water, it helps increase air flow and root canals in the soil (fake soil aggregates). Correct me if not. I could easily be wrong

[Shiffdaddy]

Eh nvm did my own research ><

Advantages of Horticultural Perite

* Improves aeration and drainage
* Makes moisture and nutrients readily available to plants
* Is inorganic and does not deteriorate.
* Has an essentially neutral pH of 6.5 to 7.5.
* Serves as an insulator to reduce extreme soil temperature fluctuations.
* Is sterile and free of weeds and disease.
* Is clean, odorless, lightweight, and safe to handle.

Small spore space must help hold onto capillary water which also dissolves and collect nutrients. Much like clay would do. Interesting, i'm talking to myself

[Cym Ladye]

Shiffdaddy,

Thanks for the input on this. I have always used an expanded perlite in the form of #3 or #4 Sponge Rok for just the reasons you stated. I also use a couple of other inert ingredients, which do not break down either, but that would be giving away all my secrets and not really needed for the basic mixes I tend to recommend.

One point on the "safe to handle" statement. This is one product you do not want to inhale as it can definitely irritate the lungs! To avoid the dust I wear a mask and wet it before adding it to my mix .

CL