It depends on what the groundcover was. Many are very tenacious and will come back. If you didn't put the soil in yet, put landscape fabric in the bottom of the bed. If the soil is already there, hope for the best and be prepared to pull out pieces of groundcover from your bed. If you are tenacious also, it will eventually die out. (Except for oxalis)

If you have not put the soil in yet, I would go with cardboard instead of landscape fabric. It might kill the ground cover before it turns to compost. I had it in one of my beds and it caused way more problems than it helped with. If you have put the soil in, good luck. Some of them are very hard to get rid of.

lgteacher- is there any way to get rid of oxalis????????
It has INVADED me!
I don't mind the pretty stuff we saw all over Santa Cruz last week, but the kind I have is a very DENSE cover , low growing and getting worse! Nancy