How to get grass out of a vinca bed?

I have a large area planted with vinca minor.
the last two years grass has taken over.
i can not find anyway to get rid of the grass without killing the vinca.
  2 answers
  • Shoshana Shoshana on May 16, 2017

    Try laying down layers of newspaper and then covering that in mulch. It should suffocate out unwanted grass.

  • Just peachy Just peachy on May 16, 2017

    I use cardboard, but you'll have to weigh it down. What kind of grass is it? Maybe the area is getting to much sun. Vinca can really take over with the right conditions.