For winter protection, I know wood chip mulch is supposed to be placed a few inches away from the base of the plant for breathing room. Does the same go for straw mulch?
In general, no mulch should be piled up against a woody trunk or woody stem. If you're using straw for insulation purposes because winter is coming, just leave a little clear space, an inch or two all round, the trunk, but if you're covering up herbaceous perennial plants which disappear below ground in winter, you don't need to worry, you can just heap it over the top, its really woody stems you need to worry about, particularly trees. The trouble with straw though, if its loose laid on top of soil, it'll blow around in the wind and could finish up anywhere.
hi i am a gardener on a large property lots of trees large 3 blade ride on mower so grass growing around tree trunks is a problem usually solved by spraying ..i do this once then throw the grass clippings at the tree base with the mower ...i used to worry about trunk rot as it is wet here in new zealand...but as stated above once or twice a year check to see that 2 inches is cleared around base otherwise the advantages of never spraying again coz of the mulch factor outweigh the risks