Working with the seasons means constantly adapting and changing. A slightly mild winter can have a big effect on early Spring. A cold Spring can have the same effect on Summer. A tomato crop that came in in May of one year can come in Late July of the next. Saying that a particular veg is "in season" in Ireland is difficult to do. When nature decides it's ready, or not, that's when it's in season. In 2010 we were still harvesting & selling tomatoes at Christmas, whereas a few years previous there was none after August.
Over the years we have managed to hone a few practices. and with the help of PolyTunnels and careful variety selection we are able to grow salads, spinach and kale all year round. Everything else is ready when it's ready!