Hi silverrowan, some of my personal favorites in low(er) varieties - all ones I've grown myself, are Park Princess (pink cactus), Yellow Happiness (sunny yellow, nice form), There is a red waterlily form called Japanese that stays low and has lovely flowers. A beautiful pastel blend is zingaro. Le Baron gets about 1m tall for me - needs staking but is bushy and blooms like mad. Velda Inez - nice lavender/white blend. Firepot is an amazing sunset blend that is stunning. Bishop of Llandaff or Japanese Bishop (or bishop's children) are all in the range and have dark foliage, as does Fascination.

Nonette is a low orange variegated with red that is very nice.

As you know, you MUST dig the lower varieties - I guess in Toronto you have to dig them all! I don't know how many of these varieties you can find in Canada.

If you like the REALLY low mounded ones just "for show", the gallery dahlias are only about a foot tall and wide. The ones I mentioned above all have stems that you can cut.

Thank you very much!
Its great to have a starting point - a lot of the local dahlia order places don't mention the plant height, so this helps a lot!