The most annoying thing about a kikuyu or couch lawn next to your garden is when it invades and gets in amongst your plants. The reason why this happens is that kikuyu (Pennisetum clandestinem) and couch (Cynodon dactylon) grasses have Rhizomes (under ground runners) besides Stolons (like all other grasses). It is the Rhizomes that allow the grasses to travel under brick or stone edging and then invading your garden bed. You can remove kikuyu from your garden bed either by pulling it out or spraying with Roundup. When you pull out the kikuyu the grass breaks off the ground and just grows back, and if you spray with Roundup you get lots of collateral damage. The safest and most effective way of controlling grasses in garden beds is by spraying the kikuyu with a selective herbicide called Fusilade Forte by Syngenta. Fusilade Forte is 100% effective and the offending weed ie kikuyu dies over a couple of weeks and the garden plants carry on as if nothing happened.