I used to work with a group of people who are very dedicated to the control of a very invasive species known as Brazilian Pepper. It has lovely red berries and was originally imported for decorative purposes. BUT, it takes over. In South Florida it is out of control. The goal in our area is control; eradication is a pipe dream. We did a huge amount of "Pepper-Busting" in the area near the cache, so I went to see if they were back - they are. They are remarkably resilient and resistant! I imagine the Pepper-Busters will discover them, also. I hope they don't discover the cache; a possibility but not a probability.