How compact should potting mix be and what should be used.

[Richard Hole]

Hi



How tight do you suggest packing the potting mix for Nepenthes? I always thought it had to be packed as tightly as possible. However, I read today that if pure sphagnum moss is used, it is best to have it a bit loose. See http://www.omnisterra.com/botany/cp/list/cp99all.d/0327.htm



An advantage of not packing it too tightly is that a bag of sphagnum moss would fill more pots and the cost per pot would be less. However, if it is too loose, the roots may get disturbed if the plant is bumped and the potting mix may not be in good contact with the plant.



If a bag or a hand-full of moist sphagnum occupies a certain volume (x) when it is compacted in a pot as tightly as possible, how many times greater a volume would you suggest it be compacted? Would double the volume of the tightest compaction possible be too loose?



I was thinking of using pure coir chip for a potting mix as it is cheaper than sphagnum moss, but some people say it has problems and it can contain salt if the coconuts are grown near the sea and the coir has not been leached well with water.



I would like to use pure sphagnum moss. However, it is a bit expensive if it has too be packed tightly. I have read that Perlite can be a health hazard if breathed in or handled so I prefer not to use it. A pure medium (for example 100% sphagnum moss) would have the advantage of saving the time to mix a potting mix up.



Any suggestions for a good mix would be appreciated. If you suggest one, please indicate if you have tested the plant growth rates against other types of mixes.



Your help will be appreciated,
Regards Richard.