I read that for almond trees, you should plant another tree of a different variety. That confuses me.
I had always thought that if you planted different varieties of the same kind of plants near each other that the fruit/vegetable would cross-pollinate and wouldn't bear 'true'. jFor instance, if you planted a bell pepper near a hot pepper, the hot pepper wouldn't be as hot, and the bell pepper wouldn't be as mild, because they would end up sharing qualities.