The cultivars are also listed in Plant Files right after family/genus/species. Not all plants have a cultivar though so maybe that's why you haven't seen it for the plants you've been looking at. Here's an example of one that does have a cultivar: http://davesgarden.com/pf/go/54644/index.html
If you're like me an don't know all the names or even which is a family name or genus, I click on the generalized search and you can type in any of it and it will usually find what you are looking for. I call it PF for dummies, like me!!!!
I love my garden and now it looks like I will be moving maybe its a good thing since I have no space to plant more babies in this garden in the past three years I have won five awards for my garden two for best front garden and three for best over all garden it is hard since I change most of my garden every year maybe I should go all natural in the new garden just to see what grows on its own hahahah weeds.
It is now March we did move to the national capital area and we have over 400 centimetres of snow fall so far this winter and more coming well for the imperial that is over 13 feet of snow, when will it be gone maybe by the end of may if we are lucky lol hahahah
The burgundy plants in the back along the fence, are those Hollyhock? I can't tell. They are beautiful. If that doesn't make you crave spring...
When you move are you still going to be in the TO area?