tomatoes on hot Sardinian Terrace

[botanikk]

Hello everyone. I thought I'd post a message here and see what advice people can give me. I'm an American living in Sardinia, and have tried to grow tomatoes on my terrace with very limited success, even though I've read about growing them in containers, etc. The summers here are quite hot, and the climate in general seems to resemble that of the Napa valley in CA. The problem is that I get very little fruit set, problems with blossom end rot (which I know is caused my a calcium imbalance from cycles of dry and wet). In the summer, tomatoes decline rapidly, at least mine in containers. if you go outside the city, you see plenty of fields of tomatoes thriving in the hot dry Sardinian summer,with lots of fruits. I've tried varieties more suited to hot climates, but it doesn't seem to make much of a difference. I assume that I need to provide some afternoon shade and water even more frequently, but would love to hear from container gardeners in similar climates for some advice.
thanks,
Aaron in Sassari, Sardinia