In article , Mike Lyle mike_lyle_uk@REMO
VETHISyahoo.co.uk writes

That sounds interesting. I've never had much to do with these plants,
and thought they were fixtures like most others. I wonder if they
eventually exhaust the soil of some nutrient which isn't quickly
replaced by natural processes, and so have to move constantly onward.
Could the plants' high silica content in some way have a bearing on
this? Or is there some complex mycorrhizal association which can
peter out in less than perfect conditions?

They don't seem to tolerate constant removal of top growth - eg regular
lawn mowing.
--
Kay
"Do not insult the crocodile until you have crossed the river"