new techniques for the growing of Cymbidiums

[Des]

Whenever a new orchid book hits the bookshelves of my local bookshop I am first in the line to see if it contains any new information on growing cymbids , but i am mostly disappointed . It is almost as though time has stood still , and and there has been no progress made over the last 50 years or so. Yet I know that this is no so, .....mumble groan moan moan...............

[orchids3]

Have been growing cymbidiums for 25 years now and have seen changes in potting mix and have tried a few also fertilizer. Or you might say I have learned a lot and changed much in 25 years. I got a collection of AOS publications back as far as 1949 from my friend Mary McQuerry - one of my first projects was to go back thru time to see how may cymbidium potting mixes were recommended. As I remember there were 35 differant mixes - many of which I would not even consider trying. We tend to adopt the technique which fits our growing conditions. I use a mix consisting of 50 to 70 Percent CHC and 30 to 50% Pearlite or 1/8 inch stalite. Thats my latest and I will stay with it I believe.

[Des]

I have been growing cymbids for 20 years and have grown them in a number of different mixes over the years
I am currently using coarse grade coconut husk chips with nothing added and found this to be good the only problem is its high salt content which has to be washed out . I also find that it is light and that the winds we get here blow the pots over , so i am thinking of using stone chips in the mix. My point is though , that it has taken us through trial and error 20 years to get to where we are today. I find that most novices who try and grow cymbids here eventually give up because there is so little information available . As far as I know there is no A to Z of growing these wonderful plants . when new books are written on the subject the actual information given goes back to the year dot. So often i read about "giving the plant a drying out period " I think this phrase has most probably killed more cymbids than any bug . Many novices will let their plants get to be bone dry before watering again. I also often read " do not over water " My plants have been standing in trays of water for years and I have yet to lose one like this. In my experience Cymbids love oxygenated water with a small amount a nutrient , at anytime of the day and at any time of the year . If the weather is cold I will water the root systems only keeping the leaves dry It is not excess water that rots the roots ,but the mix which gone sour and should have been replaced months ago. I get a lot of my information from magazines as well also just lately from the internet But I so wish that the guys who write books would do the research , leave out some of the pretty pictures and give the novice grower some good information .

[Bird Song Farm]

Thank you Des and Orchis3, your information and insight has helped me to decide which way to go with my small number of Cyms. As a novice I am always seeking information and finding some from "old time grorwers" is invaluable.
Al

[Ray]

I used to import a lot of Chinese cymbidiums, and in discussions with the producer in Taiwan, I found they were growing them in a very open mix of tree fern chunks and pumice, and fed and watered them daily (sour milk as the fertilizer - yecch).

Figuring that sounded a great deal like semi-hydroponics, I decided to try that. Now all of my cymbs are grown that way, and they love it!

Des - when preparing CHC, try adding some calcium nitrate and/or Epsom Salts (magnesium sulfate) to the soak water. I use about a tablespoon of each per gallon. It's use is derived from water softeners:

Most water "softeners" expose incoming water to a brine (NaCl) solution. Sodium chloride will dissolve more readily in water than will the calcium- magnesium, and iron minerals (mostly carbonates) that are the most common minerals in "hard" water, so they precipitate out, leaving the sodium in the water. Orchids do not like high-sodium water, so we all recommend that folks don't used it. So now let's shift our thinking to media preparation.

In that case the sodium is already in the medium, and we want to get rid of it. If we expose the CHC to a solution full of calcium and magnesium ions, that same solubility imbalance is there, but this time we extract the NaCl from the chips into the solution, replacing it with CaNO3 and MgSO4 (good plant nutrients). Then we dump the liquid, and the majority of the sodium chloride goes with it.

[Des]

Thanks for that Ray, I use calcium nitrate and mag. sulphate in my fertilizing program so the answer has been under my nose for some time. Just goes to show you are never too old to learn. It puzzles me though as to why there is so much salt in chc. Is it perhaps used as a preservative to keep the pathogen count down ? And I have just had a thought, as I said I use CaNO3 and MgSO4 in my fertilizer program would this lower the salt content within my pots? It could explain why some of the salt intolerant plants in my collection like Coelogne Cristata and the Miltoniopsis have been doing so well since going on to the program.

[Brian Monk]

CHC has a variable amount of salt, depending on where you get it. As I understand, coconut husks in some areas are transported by simply collecting them in a net and towing them to the next island, behind the boat, in salt water. Some coconut husk is not.

There is an excellent thread on coconut here:

Coconut problems - The Slipper Orchid Forum - The First Online Slipper Orchid Discussion Forum

[orchids3]

The CaNO3 and MgSO4 sounded good to me and I have used it and it doesnt hurt anything but chemists and I mean good chemists tell me that it really doesnt help. The only way to get salt out of pots is to disolve it and wash it away. The energy levels required to get salt out of any media due to chemical reaction is just too high. I find if I soak and wash my chips unlil no color comes out it works find. Checking with a TDS meter is good and confirmed this but they dont last very long. I do well in CHC that I wash out the color though.