- Sat Jul 02, 2011 8:42 pm
#110398
I have been using coir in growing mediums for more than 2.5 years. Last year I decided to do a side-by-side experiment. In April, 2010, I potted 6 medium-sized B52 Venus Flytraps with similar-sized bulbs, by first separating them into two groups of three, then planting each group of three into a 10-inch diameter pot. Both pots are identical polyurethane foam planters, and the Venus Flytraps have grown together in exactly the same conditions and with the same care regimen for the last 14 months.
The photo below was taken today, July 2, 2011. The 3 Flytraps in the pot on the left are growing in a traditional 50% sphagnum peat moss medium with sand and perlite; the 3 Flytraps on the right are in a pot that contains a coir medium, 12 parts carefully desalinated coir (coconut husk pith) to 5 parts silica sand, by volume.
Sphagnum peat moss and coir growing mediums comparison, 14 months of growth
To anyone who would like to try coir, remember several things--
The photo below was taken today, July 2, 2011. The 3 Flytraps in the pot on the left are growing in a traditional 50% sphagnum peat moss medium with sand and perlite; the 3 Flytraps on the right are in a pot that contains a coir medium, 12 parts carefully desalinated coir (coconut husk pith) to 5 parts silica sand, by volume.
Sphagnum peat moss and coir growing mediums comparison, 14 months of growth
To anyone who would like to try coir, remember several things--
- "Coir" is a name that's thrown around a lot and means different things to different people, including the chopped fibers of a coconut husk (which is not what I use) and the pith that surrounds the fibers in the husk and which is discarded as a waste product (now a commercial byproduct) of the processing of coconut husks to extract the fiber for various uses including marine rope. This pith, sometimes called "coir dust," is what I use.
- Regardless of anything the manufacturer claims, the coir must be thoroughly desalinated by repeated soaking and draining for 8-12 hours soaking at a time, 8-10 times or more until the TDS of the drained water is consistently under 60-70 ppm, preferably around 50ppm or lower (which is about equivalent to what sphagnum peat moss contributes in soluble material to the water in the growing medium).