Mayo62 said:I'm not exactly sure if I'm in zone 9... 
Are the zones about the average minimum temperature or the lowest minimum?
Mayo
According to the USDA: "Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred in the past or might occur in the future."
The Pacific Bulb Society has a page that gives the equivalent hardiness zones for different parts of the world, there's a map for Europe:
http://www.pacificbulbsociety....
It's a little hard to read that map but I think it puts you in Zone 8? According to this Wikipedia page Amsterdam is 8b:
https://en.wikipedia.org/wiki/...
