I'm looking for anywhere that might give me a 'quick guide' or 'dummy's guide' to the best general growing conditions for crops and, ideally, what the best types of season for them are.

Specifically, I am looking at a Europe-esque continent with a climate ranging from continental in the south (similar to northern Italy, mid to southern France) all the way to a more Scandinavian type climate in the north. Obviously, I'm aware that a mild summer in Norway would be different to one in Britain or France. I'm looking for general, ideally how crops go against each other.

For example, after a remarkably cold and long winter, followed by a very warm spring and a mild and wet summer, our apple and pears in the garden have done very well. However, I believe the same conditions have not done so well for grains. I want to have conditions in my country that can create a good apple or pear harvest, but a poor one for most grains (wheat, barley, rye), and I want it to be at least believable if not entirely accurate.

The technology is medieval-esque, though I reserve the right to mix-and-match as I choose, given that the Romans had running water where the so-called dark ages did not. Magic is forbidden in this particular country, so plays a negligible part aside from the king's bond to the land (which is only important at specific occasions and only results in a harder winter than usual - but I'm interested in the harvest before the king dies and his son is unable to complete the bond for months).

Any help would be most appreciated - thanks!