Ask-a-Dave's-Gardener: Green worms eating the roses...ughhhh. rose slug?, 0 by Pistil

Pistil wrote:
Oh and another thing I thought of while doing the dishes-
Hardiness Zones are from the USDA, a US government agency, but have been adopted in many other countries (using Celsius of course).
Heat Zones are from the AHS (American Horticultural Society) a private group, they are new so less known.
You may have also heard of \"Sunset Zones\". These are from Sunset Magazine, and are a good attempt to incorporate both coldness and summer heat into one zone system. You are likely Sunset Zone 4, like me. Just for comparison, the mountains are Sunset Zone 1, Seattle is Sunset Zone 5, Portland is Sunset Zone 6, San Francisco is 17. You might want to take a look at the Sunset Western Garden Book, where this is all explained, and many many garden plants and shrubs and trees are listed by zone. It\'s not perfect of course, some things I can grow are not listed for my area, but it is an excellent starting point for newish gardeners. This Grevillea is an example of one that I grow, not listed as hardy here (of course if we have a \"hundred year freeze\" this winter I may be singing a different tune).