FlytrapCare Carnivorous Plant Forums

[Steve_D]

Hello all--

As most forum members know, I have been working with coir (coconut husk pith) to try to make a growing mix alternative to sphagnum-peat-moss based mixes. I love the consistency of coir mixes as well as both the water and air retentiveness of coir. It looks and acts like a great growing mix.

However, after several months I am beginning to see what I believe are some negative effects from using coir in a growing mix, specifically stunting of growth and possible salt burn (chemical burn from too many dissolved minerals/mineral-salts in the medium). Top watering only, instead of bottom watering, and occasional flushing of the medium several times in quick succession, might reduce or eliminate such effects, but for now I have repotted all my most valuable or favorite plants into my usual sphagnum-peat-based growing mix (50% sphagnum peat moss, 30% silica sand, 20% perlite, all by volume, not weight).

I just wanted to let everyone know that, despite my initial enthusiasm about coir-based media, I now have some doubts and reservations about it. This is depressing to me because I very much wanted it to work because as I said, I love the consistency of the coir mixes and other qualities of coir. Perhaps further experimentation will reveal ways to make coir work. I hope so because it is a renewable and plentiful resource, unlike sphagnum moss.

Best wishes,
Steve

[Matt]

Sad news indeed Steve. I too wish that coir had been a good answer for potting our VFTs. Thanks a lot for the update and for conducting the experiment in the first place!

[tejan24]

thanks for the up date, sad to know it didn't work as we were hopeing it would.

How are the seeds doing in the coir.

[Nickrober]

That's sad news, I loved the look of coir. Hopefully someone can find a way to make it work.

[kevinqwe]

wow that sucks
any pics

[Aging_Bourbon]

told you....

[renesis]

I feared something like that. Might be best to still keep a peat component in the media to dilute the coir down to ~15-20%.

Good luck, and thanks for the update!

[afh928]

Ya win some, ya lose some Steve-O!

[watnazn]

Unfortunate. I still enjoy how peat is though.

[Nickrober]

I've been trying to do some research to find out what would cause Coir to be unsuitable as a growing medium for Venus Fly Traps. Here are some of the problems I've found so far:

- "Venus flytraps are grown in mixtures of sphagnum peat moss and/or peat by growers, often with the addition of sand, perlite or other inert salt free material. Soil pH should be in the range of 3.9 to 4.8." --WikiPedia "Coco peat generally has an acidity in the range of pH - 5.5 to 6.5." --WikiPedia
- "Coco peat from Sri Lanka and India contains several macro- and micro-plant nutrients, including substantial quantities of potassium." --WikiPedia "Hard water, fertilizer, copper based, and soap based products would all be harmful to the plant as would any salts or minerals that add calcium, magnesium, potassium and such..." --GardenWeb

Maybe flushing large amounts of rain water through the coir could clear up some of these problems, I'm not much of a soil or pH expert, so I don't really know. I just want coir to work because it looks so good compared peat/perlite/sand...

[Siannuro]

I'm very sad about the news. Like some here, I too was hoping it would work because [coir] is renewable. What if you soak some of it in a bucket with rain water for a day then wring it like a sponge then soak it again in rain water...? Just doing this for maybe 3 days and see if it removes most of the salts?

[renesis]

I've been trying to do some research to find out what would cause Coir to be unsuitable as a growing medium for Venus Fly Traps. Here are some of the problems I've found so far:

- "Venus flytraps are grown in mixtures of sphagnum peat moss and/or peat by growers, often with the addition of sand, perlite or other inert salt free material. Soil pH should be in the range of 3.9 to 4.8." --WikiPedia "Coco peat generally has an acidity in the range of pH - 5.5 to 6.5." --WikiPedia
- "Coco peat from Sri Lanka and India contains several macro- and micro-plant nutrients, including substantial quantities of potassium." --WikiPedia "Hard water, fertilizer, copper based, and soap based products would all be harmful to the plant as would any salts or minerals that add calcium, magnesium, potassium and such..." --GardenWeb

Maybe flushing large amounts of rain water through the coir could clear up some of these problems, I'm not much of a soil or pH expert, so I don't really know. I just want coir to work because it looks so good compared peat/perlite/sand...

If you are really interested, I think I posted up a lab analysis in another of the coir threads. Off the top of my head, the salts in it are mostly K, Na, Cl. I usually test the pH in the range you mentioned.

I'm very sad about the news. Like some here, I too was hoping it would work because [coir] is renewable. What if you soak some of it in a bucket with rain water for a day then wring it like a sponge then soak it again in rain water...? Just doing this for maybe 3 days and see if it removes most of the salts?

It would remove up to half the salts in theory, but you would have to continue doing it to get them down really low. And the nature of coir likes to hold on to salts, which makes it a great component for a regular growing media for other plants, but harder to fully leach out. I've got a bucket of coir chunks sitting in some distilled water (for over a month now), and you can't even see through the water anymore.

[Steve_D]

Maybe flushing large amounts of rain water through the coir could clear up some of these problems, I'm not much of a soil or pH expert, so I don't really know. I just want coir to work because it

Right. Thanks for doing some research Nick. I soaked and rinsed the coir in pure rainwater for days before drying it for use. The problems showed up very slowly, which makes me think that the causes are minor but significant over time. I'm not sure that the slightly less acid nature of coir was a problem. To me it seems definitely like salt stunting and burn: too much dissolved solids. Watering and flushing from the top instead of watering from the bottom might help, and perhaps can flush out enough solids to clean the coir over a period of a year or two.

I'm not done with coir yet and want to do more experiments because I really do like it for its various characteristics. But right now I've switched back to a sphagnum peat based mix.

Steve

[Matt]

To me it seems definitely like salt stunting and burn: too much dissolved solids.

Can you or did you take some photos of the problems you saw Steve? If so, I'd like to see what exactly salt stunting and burn looks like so I could diagnose it in my plants.

[rainydays]

Hi, i havent tried coir with dionea but im having ago again using coir perlite and propagating sand with drosera and some sarracenia. This time watering less , allow the media to partly dry off and watering frequently but in small amounts.
I will let you know if the 3 sarras come out of dormancy (winter in australia atm), atm my drosera are growing fine in a coir mix.
Steve, how have your sarracenia responded to coir so far?