Are you meaning to mix it all and fill the beds with it? I would personally
compost the lot (not the dirt!) before using it, straw in my
experience takes a long time to rot and sawdust has a irritating habit of clumping and going nasty. If you did want to compost straw and sawdust you would need to add a lot of greens or
pee or some other form of nitrogen. I don't think that mixing it all into a
raised bed and trying to plant anything would work well.