Our planting plans are designed to limit the need to replenish mulch on a regular basis. We do not use weed barrier and we use only shredded hardwood bark. Bark mulch is superior to wood mulch because wood mulch attracts termites whereas bark mulch does not. All of our plant beds have a three inch spade cut edge. This allows the mulch to be full depth right out to the edge of the bed. Some clients choose to have us install a 3/16″ x 4″ brown steel edging. This edging is flexible enough to accommodate curves but rigid enough to stay straight when necessary. We have found that dense plantings, once established, are sufficient to keep most weeds out. It typically takes two to three years for a planting to become established and during that time, it is important to watch the plants and water generously when they start to wither. However, some clients choose to buy an inexpensive irrigation system rather than watering as necessary.
It will also be important to apply fresh mulch in the spring for the first couple of years. After the planting is established it will be sufficient to simply cut the dead perennials back in the spring and leave the dead tops between the bases of the plants. These tops keep the sunlight from getting to any existing weed seeds until the perennials come up. The tops also have seeds which work into the ground and sprout to fill any empty areas. This system limits but does not eliminate the need to maintain a bed. It will still be necessary to pull a few weeds throughout the year and to replenish the mulch along the edge of the bed once or twice a year.