>> But the great thing is that it seems to breed true <<

Awesome.

>>I learned at my mother's knee that there are some things one should just never buy out of season, because they are not only expensive but flavourless, and tomatoes and strawberries are prime among those.<<

True of most supermarket tomatoes, not necessarily all. If it smells like tomato, it will taste like tomato. The small ones that come on a vine are often good. Also the mixed carton of cherry tomatoes tend to be excellent. Strawberries, it's a lot harder to find fragrant ones out of season.