Paul Sutphen wrote in message
After reading Diana Walsted's book, I am wondering if the Vall is being
killed by dwarf Saggitaria. What is happening is that the Vall which
was healthy began to uproot after the Saggitaria began taking over. The
Vall roots are brown, short and look rooted. Diana devoted a lot of her
book on plant allelapathy (sp?) where one plant specie in order to survive
can produce poisonous chemicals that kill other invasive plants. Im am
looking for any readers who may have experienced similar results between
Vall and Saggitaria.
I have never had good results growing both sags and vals. Leigh and I had
noted some time ago that she could grow dwarf hairgrass but not lileaopsis,
while I had good luck with lileaopsis but not dwarf hairgrass.
These are examples of plants which occupy very similar environmental niches
and have very similar growing requirements to each other. I think it is
more likely that if one or more condition in a closed system is even only
very marginally more favourable to one species over the other then that
species will quite quickly outcompete and replace the other.