I have done this but I buried leaves and all.

Bump!
I now have 6-12" on most of my dahlias and am ready to add soil. Any other thoughts about whether to pinch the leaves off or leave them on?
Thanks!

I always pinch off the lower leaves, as it allows for better air circulation, and hence there is less probability for mold to start. Do both,- add soil and pinch off the bottom leaves to about 6 inches above the soil when it is tall enough. The plants will love it.

Thanks jroot, that is what I'm going to do. I have a heavier container mix in my potted dahlias and I was reluctant to bury those leaves for fear of rot. The ones planted out in the garden still have a little way to go before I can pinch so maybe I'll experiment with some pinched and some buried.