There are, of course, problems with outdoor things like powdery mildew and mold from rain. And for some reason, at least in the Pacific Northwest, I've always had problems with caterpillars for some fucking reason. Those little bastards love my plants. So, it takes a little bit more management and your environment is less controlled than indoor, but I personally think it's easier. And I still grow so much that kind of doesn't matter if I lose a little bit to mold and bugs.