On Fri, 15 Jul 2005 01:10:17 GMT, Elaine T wrote:

I have some water lettuce plants in shade that are fine but the ones in
the direct sun have outer leaves yellowing and dropping. The pond has
an eastern exposure and gets strong sun from early morning until about 2
pm. The plants with the longest sun exposure have the most yellowing.

I had a bit of chlorosis in all of the plants a couple months ago so I
started fertilizing with iron, trace, N, and K (phosphates are fine
around 0.5 ppm) fishtank-style. Everything greened up nicely except the
outer lettuce leaves. Can too much sun make the outer leaves of water
lettuce go yellow?

IME, too much sun seems to be the problem, though again, there are always
exceptions. I keep mine in shade. I sometimes wonder if it could be lots of
sun raises the metabolism and if there isn't enough to feed on, might be
what causes the yellowing? ~ jan

~Power to the Porg, Flow On!~