coconut husk chips: good or evil

[TyroneGenade]

Back in 2006 there was the following reply in response to a question about CHC:

Stephan,

Xavier mentioned something about this too... CHC is sometimes contaminated with Fusarium, which produces hormones that promotes strong root growth. As soon as the hormones run out, the plant will die.

As for the leaves, that is expected when growing in CHC... Not to be rude or anything, but I would suggest transfering your plant into some other sort of medium other than CHC...

And as for "could" be dangerous, I believe there is enough research done by Xavier to prove that CHC is nothing but deadly, treated or not. It takes time, and not always will it have the same effects as others.

-Pat

It is now 2013 and I would like to know if there are still people who feel the same or have most people converted to CHC? I am very curious... I have been asked to prepare a lecture on potting Paphs and have decided to start by researching CHC. Other topics will follow.

I am interested in the following information:
water retention: how frequently do you water?
fertilization: what ferts work well, which don't?
how often do you need to repot?
Pretreatment: Ca(NO3)2 or MgSO4 or both?

Any other info would be appreciate. Oh, and I would like to see photos if you have them.

Thanks

 

[wjs2nd]

I don't use CHC because of preference. Orchiata bark works well with fewer risks of salt build up.

I do have one orchid mount on half a coconut husk and it does very well!

 

[dodidoki]

I don't use CHC because of preference. Orchiata bark works well with fewer risks of salt build up.

I do have one orchid mount on half a coconut husk and it does very well!

I do not use, too. I use it before, after beginning good resullts(many new roots) I suddenly lost almost all of my plants. I think it is good as root indicator but after I advice to repot paphs in bark.

 

[ehanes7612]

after growing in hundreds of plants in CHC..here is my take..i think you get a lot of good roots because CHC soaks up water and provides a humid environment, but not wet because it acts like a sponge. It also allows plenty of air just because of the way bark is striated..my brachys, phrags and parvys love the stuff (i have to water more often for the phrags though)..with that said i think the biggest problem with CHC is its tendency soak up water and not provide enough to the roots..this can be a problem with wet loving multifloral paphs..and even greater problem for adductum/anitum, lowii, and sanderianum/some sandy hybrids..especially once these guys reach a certain age and start soaking up water like its out of style.Another huge issue with CHC has to do with how it breaksdown..it just turns to mush and loses its properties ..it actually can be beneficial (as a sort of compost in the top layer, but acts as a toxic brew in the bottom part of the pot) so if you use CHC its absolutley vital to leave the bottom third with inert material (ie styrofoam). I dont know about hormones (seems far fetched)..but i can agree with CHC having an issue with salt buildup , which seems to me would happen if your mix dries out too much (easy to do with CHC) and you dont fertilize accordingly to your mix. I would discourage use of CHC beyond seedlings that are beyond compot age ( that point when their roots dont like to dry out anymore)..i repotted most of my plants(including seedlings) in bark/perlite last year just for continuity and less watering..will do the rest later as they arent ready to be disturbed yet, but they are brachys/parvys and phrags


with CHC i had to water every two to three days (four to five now with bark), and when i started growing in CHC , i asked a lot of vendors and they said they would never grow in CHC cause they cant water so often

i used ( and still do) a low K (seaweed) with a High N (Fish) fertilizer , every other watering in the summer and once a month in winter (fish fertillizer and seaweed seems more forgiving than the regular salt fertlizers)..i changed to a Low K a few years ago (on Rick's advice) and over a six month period noticed a significant change in leaf viablilty (color and texture) but i still grew in CHC for another 18 months afterwards and still had problems with my adult multi's..so i am hesitant to think CHC has any significant nutrient upload effect (thats just my gut feeling though)

with CHC i had to repot every year,..which is suicide for many plants and probably the biggest reason to give up CHC

I never pretreated but i used Epsom Salts once a month anyway (i never noticed any effect)

 

[Rick]

CHC is not just able to store salts but is an active cation exchanger.

It likes to suck up and hang on to Na/K and give up Ca/Mg

So everytime you ferilize with a high K system it preferentially hangs on to the K (unless you add a disproportionate more Ca).

If you flush with RO it hangs on to the K regardless. You need to flush with a solution containing Ca (and/or Mg) to purge the K out of the CHC and move Ca/Mg back into it. I didn't mention Na since we usually try to avoid water with significant sodium. But for some people using surface waters, this would be a compounding issue.

Actually bark and sphagnum do this too, but not apparently as extreme.

I've moved quite a few orchids back into CHC based mix with very good results since K lite, and TDS monitoring.

 

[ehanes7612]

CHC is not just able to store salts but is an active cation exchanger.

It likes to suck up and hang on to Na/K and give up Ca/Mg

So everytime you ferilize with a high K system it preferentially hangs on to the K (unless you add a disproportionate more Ca).

If you flush with RO it hangs on to the K regardless. You need to flush with a solution containing Ca (and/or Mg) to purge the K out of the CHC and move Ca/Mg back into it. I didn't mention Na since we usually try to avoid water with significant sodium. But for some people using surface waters, this would be a compounding issue.

Actually bark and sphagnum do this too, but not apparently as extreme.

I've moved quite a few orchids back into CHC based mix with very good results since K lite, and TDS monitoring.

well, i can accept that but K aside ....i mostly think its evil because of how fast it breaks down and the need to water so often..but it seems beneficial for some species

 

[ehanes7612]

just read on Fusarium..that's pretty scary..dont recall nay plants having those symptoms though

 

[Rick]

well, i can accept that but K aside ....i mostly think its evil because of how fast it breaks down and the need to water so often..but it seems beneficial for some species

I've had it hold up for over 3 years, so not sure about the fast break down thing.

 

[ehanes7612]

I've had it hold up for over 3 years, so not sure about the fast break down thing.

i should say i used straight CHC ..with styrofoam bottom..perhaps that's why it broke down so fast (could be a brand thing too, and how big the chunks are)..i do use a little CHC in my current mix but its mostly bark and perlite

 

[wjs2nd]

I've had trouble with my paphs blasting or not developing their buds right.

 

[Eric Muehlbauer]

For starters, I would not take anything Mahon said seriously. As for CHC, I still use it almost exclusively for my cattleyas, oncidiae, dendrobiums, basically all my epiphytes except for pleurothallids and phals, which hate it. I never used it on phrags...their dislike of it was immediately apparent. (Funny how phrags tolerate anything else, including severely decayed bark, basically turned into peat...) My paphs would like it at first, then decline after about 6 months. It does break down way to quickly in moist situations, even though its original selling point was its long life in a mix. It does last many years with my catts, etc. I gave up on it long before I started with K-lite with my paphs. I'm not about to try it again, though, as I am very happy with orchiata.

 

[SlipperFan]

I've been growing my Phrags in a CHC mix for several years (8 or so) and they seem to be doing quite well. So my experience is very different from Erics. Maybe it's where the chips originate?

 

[Eric Muehlbauer]

Perhaps, but it could also be the plants. I don't know how many phrags I tried in CHC, probably only 1, but I have never seen such a fast and negative response to a medium. Within weeks the plant just started to look like crap. So I repotted it into my usual bark/sponge rock/sphagnum mixture and it recovered. Never tried it on a phrag ever again. (No salts...I always triple soaked my CHC, using MgSO4 and CaCO3 in the 2nd soak. The fact that brachy's would do well in CHC, at least the first few months, shows that salt couldn't have been a problem.)

 

[Ross]

I had very good luck using a CHC mix with charcoal and perlite when I grew in the house, where conditions were relatively stable year round. (30-50% humidity and 60-75F). In the greenhouse, I have better luck with Pinus radiata bark, either Kiwi bark or Orchiata, although I still add a little CHC to the larger grades of bark when potting Paphs. They seem to like those little pockets of extra moisture.

 

[TyroneGenade]

Thanks for sharing your experiences.

To me it seems that CHC can work well if you use K-light fertilizer, water regularly and lighten the mix a bit. For Phrags and multis more water is needed else trouble... The quality of the CHC may also be a factor as some break down fast and others slowly. Do you think bigger chunks make for a longer lasting mix?

For the talk I will need photos... Anyone have a good photo of a well grown plant in CHC they could "lend" me for the presentation? A good photo of root development (before & after) might be nice.

 

[Rick]

Thanks for sharing your experiences.

To me it seems that CHC can work well if you use K-light fertilizer, water regularly and lighten the mix a bit. For Phrags and multis more water is needed else trouble... The quality of the CHC may also be a factor as some break down fast and others slowly. Do you think bigger chunks make for a longer lasting mix?

For the talk I will need photos... Anyone have a good photo of a well grown plant in CHC they could "lend" me for the presentation? A good photo of root development (before & after) might be nice.

I'll have to double check what my exul is in. I think its a CHC based mix, but it hasn't been repotted in 3-4 years. 20+ growths and 6 spikes this spring. I've had the plant since 2001, and maybe repotted 3 times.

 

[eggshells]

Chc is the preffered choice of nurseries in the Philippines albeit they use the big chunks (not exactly chips). Also it is the most abundant and cheapest orchid medium there. Orchid bark is very expensive there as they have to import it.

 

[Rick]

The fact that brachy's would do well in CHC, at least the first few months, shows that salt couldn't have been a problem.)

Most Brachy's come from environments exposed to ocean spray, so they are not generally intolerant of "salt".

That is not to say they are more tolerant to ion imbalances.

Ocean water is very consitent with LOTS of Na Cl followed by magenesium and calcium salts. Magnesium ion is about 3 times that of potassium in sea water.

Potassium is less common in sea water than the other major cations. If you present a condition of potassium as the most common cation to brachies (i.e watered with RO and fertilized with only NPK and no soluble Mg and Ca supplements) they will present as being very salt sensitive due to the gross imbalance of major ions presented to them.

 

[katzenhai2]

I repotted all my Paphs in 2009 into CHC. I washed them twice overnight in buckets until the water they were in had 250 µS. Bigger chips are stable for a longer time than smaller ones. Some were supplemented with Ca/Mg and others not. Can't decide a difference. But I grow all my Paphs in a greenhouse. CHC can dry out VERY quick if humidity is low (like on a window sill). Many pots standing on living sphagnum moss so they are permanent wet without having a chance of drying out.

The substrate of this P. sanderianum (young plant) is almost decomposed to humus. All sorts of millepedes and other creatures living in there. Never had problems with CHC. All my problems I had with my paphs were sourced otherweise (light, nutrient restriction because of sphagnum moss, Erwinia because of no fans in my greenhouse etc). Never a problem with buds or blooming. I use an NPK fertilizer of 14-8-7-2Mg and water with 500 µS.

In my opinion CHC greatly benefits if it has the chance to decompose to almost humus with his own ecology like bacteria, fungi, little insects etc. If it hasn't the chance to stay wet all the time the ecology can't be established and you need to repot the Paphs every six months IMHO because of the decomposed (and dead) humus!

 

[wjs2nd]

Very healthy looking! Have you had any trouble with root rot?