Well, I'm partial to sweet woodruff and I don't really like Periwinkle. That said, the two are rarely competitors for the same space because the Periwinkle is evergreen and the woodruff is, basically, deciduous. Woodruff would be used much more if it were evergreen.

Thank you for pointing that out. I didn't realize that sweet woodruff is deciduous. That really changes things. I'm so glad I posted.

Have you considered pachysandra? My inlaws use it in the Pittsburgh area, and it does a great job on hills. It fills pretty quickly, and it is evergreen.

What are your weeds? Why use either myrtle or sweet woodruff? Why not plant things of real interest - ferns, native wildflowers, native bushes, native understory trees? If you are not amenable to this opt for the myrtle. On the hillside what do you care if it sends out long stems?

I had bindweed everywhere, poison ivy, pokeweed, and sassafrass seedlings..there are a lot more but I'm not good at identifying the other weeds, but I do know that I wanted a manicured look on that particular hillside. There is a woodland area behind my home. That is where I have my ferns, wild violets, virginia creeper, a couple of stands of may apple, hosta, toad lily, scilla...etc. (Sometimes I get overwhelmed with all of the "areas") I decided to plant sweet woodruff behind my house in the woodland area...I like it so much I want to have it somewhere. I'm leaning toward pachysandra on the hillside. Actually, thats a great suggestion!!

Hi, dirtdiva--
Came across your 2-year-old post as I was doing some research on sweet woodruff. :-)
I, too, am in the Pittsburgh area and was wondering if you went with the pachysandra as you seem to have decided in your final post. If so, was it the non-native and aggressive big-box version, P. terminalis, or did you do the Right Thing (even though it is more expensive) and go with our native Allegheny pachysadra (P. procumbens)? CK

Here is a link that might be useful: Native groundcovers for sun and shade