potting with coconut bark

[Katrina33]

Hi, I’m Kathy and I’m new to this board. I bought a bedraggled orchid from Lowe’s years ago and got hooked! I had no idea what type it was, what color, etc. Several years later, it bloomed the most gorgeous color and had a
lovely fragrance. I have since discovered that it is a cattleya and I think it might be “Magic 'Carmela” based on my research. The flowers have bright yellow and red petals. I’ll try to post a photo.

On the advice of a site on line called Orchid Geek I repotted my cattleya in a combo of perlite, coconut bark, and horticultural charcoal.
(It had bloomed almost twice a year for three years and really needed a larger pot.)

Within several weeks or so, the roots looked black and they all began to die. I almost lost all but several roots ! On the advice of my local nurseryman, I quickly repotted using only the coconut bark. It has bounced back with nice root systems but no signs of blooming. Would the shock of having begun to die cause it to delay blooming? I also feel like the coconut bark is not enough potting medium by itself because it always looks dry. Even the next day after I have watered, it looks dry. Anyone ever use this bark by itself? I hate the idea of repotting again, but I am concerned.

I love how thoroughly every thing about orchids is covered! Hope someone can give me some advice!

[ColoradoBirddog]

Hi Kathy. It seems very odd to me that you would have a root die-off like that. My first thought was wondering if there might have been some salts on the medium. All of those are good to use, normally.

When you did repot, did you change your watering habit, or the growing environment? What type of water?

I'm no expert, so I hope someone might have some answers.

Kevin

[katrina]

CHC is great stuff but it MUST be soaked/rinsed several times before use or it can contain a lot of salts...which could damage orchid roots. And what I mean by soaking/rinsing is that you must allow it to soak for hours to leach the salts out and not just one time...but multiple times.

I usually did a minimum of 3 soaks/rinses (sometimes more!) and each soak was usually about 24 hrs. Not sure if a full 24hrs is needed...it was just convenient for me to do it that way. 1) Soak, drain and then squeeze out as much water as possible, 2) soak, drain and then squeeze out as much water as possible and 3) soak, drain and the squeeze out as much water as possible, etc, etc. Also, in each soak batch I added Epsom Salts to help leach out the salt in the CHC. I don't remember the official term for this but essentially the Epsom salts (not really "salt" but Magnesium sulfate) soaks in and forces out the bad "salt" we don't want in the medium. I believe the term is exchange something-or-other...not really important I guess...just important to know that if you use CHC...you must do the soaking/rinsing before using it w/orchids.

Keep in mind...CHC also tends to hold onto the salts in fertilizer and it can become concentrated in the parts that dry (top) quicker than w/other mediums so it's vitally important to not over-fert and to be sure that you are doing regular water flushings of the medium to try and keep the build up to a minimum.

FWIW - even the companies that say/said they rinsed it well...I still did at least 3 soak/rinse cycles. Just to be sure. I didn't really trust that it was done as well as knew I did it.

BTW - I got really tired of doing all the soaking and rinsing and I don't use CHC these days.

[rbarata]

Where have you got the bark?

[katrina]

Originally Posted by rbarata

Where have you got the bark?

It's not really bark...it is coconut husk chips/chunks. Which is chunks of coconut shell/husk that have been chopped up. It's great because it is chunky and airy but it holds water like a sponge and then slowly release it back out to the roots. Phals loved it! But the downside is all that rinsing and the having to make sure most of the material was removed at every repot due to it's inherent nature of holding onto the salts in fert and/or the tap water. If I didn't use tap water...that would have been less of an issue.

[billc]

I think the term Katrina was looking for is caton exchange. FirstRays used to offer calcium nitrate that was used to soak the CHC to remove the salts.
CHC is great but like Katrina said it's a pain to prepare.

Bill

Found this great article by Bob Wellenstein(Antec Labs)
on CHC for paphs but the info on CHC is useful.
Use of Coconut Husk Chips

[Katrina33]

Thank you so very much, everyone!I think you are totally right. I did not know to soak the
coconut at all. Well, I did soak it overnight to get it good and wet, but I did not rinse and repeat, etc.

Now that I have the roots looking very healthy, I am still
concerned that the coconut does not hold enough water. I find I need to add water so often because the plant feels light and the bark looks dry. I live in Columbia SC and it's been "feels like" in the 100's for weeks. My orchids are in the south window of my garage (an area I use for gardening) and I'm wondering if it's been just too hot. Maybe this medium is just not appropriate for my
weather zone?!
If I choose to repot using a new medium, will it delay
blooming yet again? ARGHHHH!

---------- Post added at 10:19 AM ---------- Previous post was at 10:16 AM ----------

Thanks for the info!

---------- Post added at 10:20 AM ---------- Previous post was at 10:19 AM ----------

Great information, thanks!

---------- Post added at 10:20 AM ---------- Previous post was at 10:20 AM ----------

Thanks, VERY helpful article.

---------- Post added at 10:21 AM ---------- Previous post was at 10:20 AM ----------

Not sure what you are asking. I have the chc all around the roots of the orchid. Is that what you mean?

[Ray]

Originally Posted by Katrina33

Now that I have the roots looking very healthy, I am still
concerned that the coconut does not hold enough water. I find I need to add water so often because the plant feels light and the bark looks dry. I live in Columbia SC and it's been "feels like" in the 100's for weeks. My orchids are in the south window of my garage (an area I use for gardening) and I'm wondering if it's been just too hot. Maybe this medium is just not appropriate for my weather zone?

Believe it or not, the need to water frequently is a tremendous thing for the plants.

When you water a dry pot, the plant takes up a LOT of water immediately, then less and less as the medium dries out. Water again and the process repeats.

Water is the driving force for growth. When water is plentiful, the plant sends hormone signals to the stomata to open, so that excess oxygen can be released and air containing more CO2 can enter. Carbon fixation is growth, which also need water to become carbohydrates. (It takes absorption and processing of about 200# of water for a plant to gain one pound.)

If water is not plentiful, those hormones are not produced, so do not trigger stomata opening, and growth slows.

The fact that you have (the opportunity) to water frequently is great!

[Katrina33]

Thanks so much, Ray. I will continue to water as needed! I'm glad to know I don't really need to repot.