John,
I have ordered from Paw Paw a couple years now and use the Avery labels too. I use a can of clear spray sealant to coat the label after printing and they last longer. Without spraying, the labels do fade with exposure to the sun and rain after about a year. The sealant I've used is Krylon Crystal Clear.
edited to add that if have always used the galvanized stakes and so far knocking on head, not had any issues with them corroding...
