My wife prefers shredded Cyprus wood. It does not wash away when it rains. We have ordered truck loads of top soil before but the mulch is always been in bags.
For the newest flower bad I had to borrow a buddies old F-250 and go get a few pickup loads of "rich mix" which is a compost made from the cattle yards bountiful supply of cow crap, composted for a while and that kills any and all seeds.
This flower bed is way more grown up now. That took two pickup loads of soil and a lot of stone work and lots of mulch and plants.
This is just after I removed all the sod and the old sprinkler heads, and the wall was still some assembly required.