Searching the archives + What Do You Think Of Coconut Coir?

Roy Herold
Wed, 28 Jul 2010 14:57:09 PDT
I had a terrible, terrible experience with coir from which I never 
really recovered. I was using some of the compressed brick types that 
are sold by many outfits, but mine came from a local plant society that 
claimed 'wonderful' results. According to recommendations, after 
hydrating I mixed it with grit or pumice or perlite, whichever seemed 
most suitable.

About a quarter of what I planted in it, mainly bulbs, succulents, and 
some general perennials, died within a year. Half went into near stasis, 
and just sat there, putting on no new growth, no new roots, complete 
zombies. The other quarter seemed happy as could be. Cyclamen 
rohlfsianum absolutely loved it, and grew into monsters. Narcissus 
absolutely hated it, and I lost most of my collection.

In the subsequent repotting effort I threw buckets and buckets of the 
spent coir in a big heap by the compost pile. This heap was completely 
weed free for a couple of years, as if it was saturated with herbicide. 
The ground around it was weedy as ever, right up to the invisible coir 

That said, I still use coir. I did more research and found that orchid 
folks who use it have a long and involved regimen of rinsing and soaking 
and rinsing and rinsing and treating with epsom salts, ad infinitum. 
Apparently the coconut hulls come from some very salty locations, and 
the processors do not wash it. The rinsing regimen is not for me, thank 
you. Instead I switched over to MetroMix with coir (don't remember the 
exact number, but I like the one without vermiculite). I still mix this 
with grit or pumice or perlite. They do all the washing for you, most 
certainly test it, and pretty much have to guarantee performance or they 
will have a lot of BIG angry customers.

Or, if you want to live dangerously, use the raw stuff and you may find 
you will soon have a lot more room in the greenhouse like I did.

NW of Boston

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