This is all very informative. Thanks to all of you. Looks like I'll be
getting my cilantro at the supermarket for the rest of the season, and let
my own go to seed. I live in Rhode Island, so I'm not sure if our summers
qualify as too hot but I'll try a fall/spring crop and see how that fares.

If it works like lettuce, I have read that what triggers bolting
is the cumulative amount of sunlight, not heat per se.

In Dallas, cilantro & parsley do well in January...

Hope this helps,
--
Bob Mounger