If you want to maximize production, yeah, you cut at certain times of the year to force the trees to put as much energy into the fruit as possible. But if you just leave them outside they will fruit as long as they are sufficiently watered and have enough room to grow. There might not be as many fruits, and they might be smaller, but it will produce. But ideally you always want to choose fruit or nut trees that are native to your region (or at least your agricultural zone) so that they require less upkeep in general.