I noticed the nurseries in our WA town had them out early last year, and they had all suffered from frost. I didn't even buy mine until after May 1, and the saleslady said I must be a real gardener, as I didn't buy them too early. I used to set mine out mid-April, with milk jugs or plastic bags covering them. Then I discovered they didn't ripen any faster than the ones I set out the second week in May. In fact,the later ones grew and produced faster than the early ones. And I learned to buy small plants, as the larger ones (with blossoms and/or fruit) never did as well as the younger plants. Sometimes you just can't hurry Mother Nature.

Granny

Here is a link that might be useful: Annie's Kitchen Garden