Already this year I've had the best harvest in several years. It's the cage, because the deer are huge and the squirrels are around as well. In spite of a very late start (end of June) other things that helped were:
I planted the day I bought them.
It rained a lot for the first few weeks.
We've had breaks in the heat so fruit can set.
If I got no more for the rest of the summer I'm pleased. 
