"High" boron levels in Bay Area water?

[XYZ]

Greetings:

While waiting on a B test kit to arrive later this week, I thought I might throw out the question to northern California palm growers who get their drinking-irrigation water from the Hetch Hetchy Reservoir whether they have noted any of the classic symptoms of B toxicity in their more delicate palms, particularly thin-leaved understory species. I am curious whether the mildly phytotoxic components of this water source, besides chloramines, may include a relatively high level of B. Ostensibly this water looks OK with pH of ca. 8.2 and ca. 20 ppm TDS and can certainly grow beautiful orchids and so forth, but there is something in it that is definitely nasty for a number of delicate plants, including some very interesting small palms. I know a few ways to offset this problem, but wonder whether others have seen it manifested in their collections in this area.

Thanks in advance for any (informed!!) feedback.

J

[John Case]

Boron is a problem in the Discovery Bay area, Byron Hot Springs and parts of the Eastern Contra Costa County. I know nothing of them in othe places, although palms seem to do well in these areas either despite the boron levels or due to them. Byrom Hot Springs was a resort to the Hollywood types in the 1930s and loads of plams are still growing there, primarily Phoenix Canariensis....