So my brother has a backyard with two 40 foot by 50 foot hillside dirt slopes (30 degree slope roughly) bordered by a retaining wall in Southern California (each slope sort of looks similar to the attached image but much more uneven and with way more weeds). It rained recently, and now the hillside(s) are covered with weeds.
Initially, he was going to do a non-woven geofiber textile fabric to prevent weed growth covered by some kind of gravel or crushed rock for decoration. Because of the slopes of the hills, he was told it would be fairly expensive labor-wise (you'd have to possibly re-grade the hill a bit, etc.) He was pointed in the direction of doing some kind of ground cover plant (myoporum or dwarf carpet of stars) spaced by punching holes through the non-woven textile fabric in lieu of the rocks as a cheaper alternative.
The goal of all this is to get a decent looking backyard that requires no water and no maintenance (e.g., pulling weeds, watering or trimming decorative plants) or as close to zero-maintenance as possible.
If he goes the ground cover route, does he need the textile fabric at all? The nursery said it could help prevent weed growth and you could get adequate ground cover by punching holes in the textile fabric along a certain interval spacing. However, a landscape designer told him that actually, you don't want the fabric in case one of the ground cover plants dies. It seems like if a plant died, you could just use trimming from the ground cover plant and start over though, but I'm not a gardener.
Other than rocks or ground cover, is there another potentially better alternative (better in terms of less time to maintain and/or the same or better cost)?
In Southern California, it seems like labor is more expensive than material (or at least most of the time it is).