Most ground covers grow to a height/thickness of 6-10" +, so choose plantings/perennials that will grow above that height. Also, as much as we all love an establish found cover, that also creates cover and natural competition for weeds. It can eventually choke out bulbs and perennials, so you sometimes need to thin out some of that growth to allow the dormant planting to push through.

I this particular case, the Myrtle is planted only along the front edge of the bed and the remaining plantings are behind the ground cover.

Thanks so much! I'll get someone to clear the groundcover from behind and around the elephant ears, leaving it in front.