Yellowing leaves are not a symptom of (heat or sun) burning. They are
a sign of nutrient deficiency or aging.

"Kathy" wrote:

Could depend what state you are in. In the south west it gets too hot and
the plants burn. Which doesn't hurt, since most of the states where they
would winter over if babied, they have been banned. I have been told that is
why my water lettuce yellows , it is burning faster than it can re-hydrate
it's self. At least that is the story I get. KathyAZ
"John Bachman" wrote in message
.. .
I notice that the water hyacinth in my main pond is not nearly as
green as those in a smaller pool that is in my waterfall stream. The
pool hyacinths are deep green and are even flowering while the main
pond hyacinths are lime green - yellow.

The pool is partly shaded by some grasses nearby but the main pond
gets full sun.

Is it possible that WH wants only partial sun?

TIA

John