Biggest mistake would be growing outside with unknown genetics. You always need a harvest window, let alone knowing if the plant will even finish in time in your area.
2nd biggest mistake would be using guanos and fish based fertilizers. Especially in an area filled with large animals that enjoy the taste of fish. Coming upon your spot and finding your plants have been dug up by a family of bears really sucks.
What's the bigger mistake? Having plants with bad genetics or not having plants at all because the animals dug them up? Not everyone is out to grow cannabis cup quality bud outdoors.