I dont know that much about growing veg, first time this spring/summer.

The first couple of batches of lettuce did fine, First batch was mignonettes,
planted from seedlings from bunnings, transplanted early sep, took a bit of
time to start but then did fine. Second batch was cos, planted mid oct
from seedlings from bunnings again.

They both went to seed after a very hot spell in mid Nov, got quite a few leaves to eat until then.

I've since planted some more icebers, 'salad mix', cos, and lollo rossa, mostly
from seedings from bunnings, but the salad mix from someone flogging them
at the sunday market.

None of them have done much except the icebergs.
They havent died, just havent done much growth wise.

The icebergs did grow noticeably, up to big bigger than a large grapefruit size,
but no hearts. Since the first two batches had gone to seed I did start using
leaves off the small icebergs. Now even the icebergs seen to have stopped.

We have had much hotter weather obviously, in fact a couple of patches
of a week or so over 40C, with some rather cooler times in between.

They get plenty of water, once a day from one of those
soaker hoses that sort of weep water rather than spray it.

Is it just that they dont like the very hot weather ?

The net seems to suggest that thats the problem.

Are there any varietys that do much better in the very hot weather ?