How do I choose an outdoor growing location?
Do not grow on your own land (unless it is remote), so that you can show that someone could have easily trespassed on your property, and violated your land by planting marijuana. A few plants should be fine, but be careful.
You may never get caught, but there is a constant threat of suspicious neighbors, hunters/hikers and worst of all, cops.
I suggest a secure location where your plants won't get confiscated by the cops or stolen by rippers/hunters/hikers. Avoid heavy traffic areas, popular hiking trails, and recreational roads. At all costs, avoid making paths to your grow location. What seems invisible on the ground may be very apparent from the air. Try a new path each time you enter or exit your location; walking along fallen logs, in dense areas and through streams, etc.
Try to have several locations and not plant all your plants in one spot. If your plants do get eaten, ripped off, or taken by cops it is nice to have plants in other locations to fall back on. These separate locations can be close (5-20 mins hike away) or distant (Completely different areas). Planting inside a dense field of brush is very stealthy.
Fertility and sun exposure
Once you have chosen a secure location, check the area is fertile, with lots of green vegetation. Dark or black topsoil with lots of bugs/worms within the first few inches of soil is an indication of a healthy location.
Valley bottoms tend to be ideal locations because rich topsoil often washes downwards and accumulates. It can be challenging to find good sun exposure at the bottom of a valley. Valley bottoms are the first areas to have frost in the fall.
A very important consideration is sun exposure. The more direct sunlight the better (preferably a southern facing slope). North facing slopes are also a good choice.
Choosing a location near a water source saves the major hassle of having to haul water in by hand. A nearby water source allows irrigation (with pumps and hoses), making watering easy. A drawback is that people are also attracted to rivers, streams, etc and may be nearby.
Having a water source near by is great, as it usually means the tap roots of the plant will penetrate deep enough though the last 1/2 or 1/3 of the season and will not require much, if any, supplemental watering. Fertilizing will still be required periodically.
Note: Scout a location during the summer and fall to prepare for planting the following spring. The site needs to have brush removed, and a suitably sized area needs to be cleared for planting. Preparing the holes the previous fall allows soil time to compost and grow beneficial bacteria.