It's the sun, which the tomatoes need. Additionally my guess is most of the tomatoes in the Netherlands are grown in greenhouses which are usually coated with UV protection, and the tomatoes do well with UV light.
I have tomatoes myself and this year they haven't tasted that great, and there's been a lot of rain and little sunshine compared to prior years. In the south of Europe you can grow the tomatoes outside although I think these days the commercial ones are also grown in e.g. polytunnels because they can get the products faster to the market.
I have tomatoes myself and this year they haven't tasted that great, and there's been a lot of rain and little sunshine compared to prior years. In the south of Europe you can grow the tomatoes outside although I think these days the commercial ones are also grown in e.g. polytunnels because they can get the products faster to the market.