Making your list private is such a drastic step. Your list helps other gardeners in your zone know the plants that probably will grow well there, and many of my purchase decisions are made because I see that the plant is being grown or is wanted by many members.
On the other hand, adding a note to your info box doesn't work. My info box says that my plants are not available for sale or trade, but I still get requests for them. After the first few cases in which the person was sweet as pie until I mailed the plants, after which I never heard from the person again, not even with the courtesy of a message confirming the receipt of the package, I stopped acknowledging the requests. For a while, I responded to the requests with a polite denial, but now I just ignore most of them.
Some people, however, contact me because they've seen that I grow a certain plant and they want planting or growing instructions. I'm happy to respond to these messages, but if my list were private they would never know that I grow the plant and wouldn't be able to ask.
