I think you'd be ok planting in the old turf. Vinca is pretty tough.

As for how many, that depends on money and patience. If you've got more money, plant them 18" apart. If you've got more patience, plant them 3-4' apart.

You've got 320 sq. ft.(4x80). To plant 12" apart you need 320 plants. For 18" (1.5') you'll need 213, for 2' you'll need 160. (see how this works?- take the sq. ft. and divide by the spacing in feet).

If you go with the larger spacing, you can shift some of it around next year. It will root along the runners, and you can move the rooted pieces.

Keep it moist this summer, and it will grow faster. Next year it will take off. I got one little piece in a hosta and after 8 years, I've got 20 sq. ft.

OMG I bought 3 vinca minor plants yesterday to try because of the lovely blue flowers, and I wasn't sure where I should plant them. They said that it needs partial shade? I got them at Walmart so there isn't a lot of information in the pot.

Creatrix would this grow in an area where there isn't a tree or something to shade them?

This is also a great plant for a pot. The shade it needs may depend on what climate you live in. I have my vinca in a pot, and the summers get very hot, sometimes 100+ and if it's in the sun the leaves burn. Personally, I find morning sun, and partial shade in afternoon works best. I also cut mine back in the spring, and it grows full and lush again.

It will take more sun the farther North you go- so it depends on where you are. Some sources list it as full shade to full sun.

I'm in zone 5. The first year it doesn't do much. In the next two It has more than doubled in size. In NE Ohio full sun doesn't bother it.

Any idea on a faster way to grow the vinca?...can it be directly sown in the soil here or do I need to start with actual plants? ...I have a very large hill in full sun that I would perfer not to mow....too steep...budget is a problem so I would like to be economical about this...Thanks in advance....