Here it is September, and most of my tomatoes are still green. The cherry
toms are just now starting to ripen, the rest are big and green. Is this
normal?

Secondly, my toms are still blooming. The blossoms being produced today will
probably not live long enough to ripen before the frost, should I clip the
branches that are blooming so that the plant puts strength into existing
fruit? Or just leave it alone?