In Pat
Kiewicz wrote:

Bert Hyman said:

On the other hand, the plants are in a corner formed by two exterior
walls of the house which is like a little solar oven; it gets pretty
warm in there during the period we do get sun.

Could the problem be heat, and not light?

Do they start getting sun only in mid-day (the very peak of
insolation)? It could be the timing of the sun exposure, though the
heat is very likely a part of it.

Yes; they're along a wall that runs north-south, which coupled with the
neighbor's maple tree, means that they don't get any direct sun 'til a
little after local noon. The other neighbor's maple tree cuts off direct
sun by about 3PM local time.


Any other avenues to investigate?

Low potassium can cause blotchy ripening.

Found this, from the Royal Horticultural Society:

"Disorders of fruit are common; greenback, where hard, green areas
develop on the shoulder of ripening fruit, is usually caused by heat
injury and insufficient potassium....

Thanks. They're definitely getting a lot of heat in a short time; I'll
check into the potassium issue nex year too.

--
Bert Hyman St. Paul, MN