I have about a sloping area in front of where my hedge wall is being placed. I don't want to have to get the mower down in there so I am planting ground cover. I got a bunch of Sedum spurium http://www.gardenstew.com/plantstew/24175 to plant there. My question is does anyone know if this will overtake the grass in that area or do I need to take the area down to dirt then plant. Problem with going down to dirt, HOA not going to like it! Sloped so erosion issue as well. If the plants will not overtake the grass, I have no choice. Any help/advice would be great! Thanks in advance!
You really need to remove the grass so the sedum can take over without competing. Also, if the grass remains you'll have a weeding problem worse than the mowing problem. May I suggest that you remove the grass, roots and all; fill with some compost to replace the soil mass you'll be losing; and then mulch heavily with a non-floating mulch (in case it ever rains here in Texas ). Then simply make an opening in the mulch and plant the sedum in the soil. The mulch will also protect the newly-planted sedums, and retain moisture as well. Perhaps if you don't tell the HOA, they won't find out! It is always better to beg forgiveness than to ask for permission . . . .
The sedum itself won't keep grass and weeds at bay. Plants are made to live together and rarely will run any other plant out of the neighborhood. However, the mulch will help greatly. Nothing deters every weed, but the mulch will suppress most weed seeds from germinating. Just keep a good 3 to 4 inch layer of mulch on the sedum bed, and you'll have only a few weeds.