Do you have stepping stones that weeds somehow find their way to between the stones?  I have a large diameter perennial and annual bed at home with annuals around the outside 2-3 feet and then perennials on the inside of the bed.  Instead of stepping between the annuals to do maintenance on the perennials, I installed a flagstone path on the backside of the bed for a walkway so I can access the middle of the bed.  This spring with the cool weather – it seemed that every weed in Rice County wanted to grow between my paving stones.  Yesterday, I planted several creeping thyme plants amongst and around the edges of the stones.  It already looks great.  In another few weeks, I’ll post another picture after it has taken hold and starting filling in. 

Creeping thyme is one of those perennials that really gets crabby when it’s confined to a pot.  It doesn’t like living in a small container at all.  It was amazing that simply overnight – it changed it’s appearance significantly and I am very anxious to see what happens the next few weeks.  It is blossoming right now and when it’s not full of tiny little flowers, it is just a nice green “mat” filling in the spaces between the stones.