consider laying the mat then slashing crosses thru large enough to remove soil,add plant,replace cut mat over rootball of plant.then add the bark, gravel or whatever. the use of low-growing plants so-called prostrate conifers especially Juniper can be very effective covering quite large areas over time and if a bit spiky possibly even deterring feline visits.

just a quick word on plant selection....gardeners who adore plants tend to produce planting schemes that can appear quite "bitty" (if i may use the term!) due to us loving different plants so much we have to aquire them.a front garden is an ideal area to excercise a bit of discipline ...if you have the space for 20 plants it can look more effective if just 3 or five kinds are used rather than 20 different sorts. you can still inter-weave and contrast different shapes and sizes and have seasonal highs.finally remember flowers are ephemeral and don t last long...shapes are there all year round ...as is evergreen foliage...even deciduous foliage is there 9 months of the year and can give autumn colour.. not forgetting berries.