I need some advice on planting creeping thyme between pavers on my front walkway. The walkway is made of concrete 1 foot square pavers with a little more than an inch between them. The gaps are filled with gravel. Over the years the gaps have filled in with weeds growing in the gravel. A week ago I pulled up the weeds and ordered flats of creeping thyme plugs. My question is whether I should try to remove all the gravel and replace with soil, or just dig out the gravel where I plant the plugs at the corners of the pavers.