dodge man
Super Star Member
Hay is grass or clover baled for feed. Straw is usually the stalks of wheat baled after the wheat is picked and is not used as feed.Really? Hay is wheat stalks (or similar grains) after the combine has cut the heads off and collected the seeds. A second optional process can then come through and cut the "literally straw" stalks that are remaining and bale them. There's virtually no seeds in straw. The seeds have already been harvested. Nice straw that's for sale is often described as "bright and clean". Road contractors and hydroseeders, landscapers, etc. always use straw -- never hay.
Hay is obviously the entire plant above the roots. Stalks/stems, leaves, SEEDS and all. All hay is FULL of SEEDS. And since any junky hay that can be bought cheap enough to use for mulch will probably be very weedy, it's going to have lots of weed seeds. Even if you use nice hay you're going to be planting lots of hay seed into your lawn area. Some of the grassy hays won't be easy to remove using selective herbicides.
Agree that you can use old junky hay as a mulch to cover grass seed and it will help retain moisture. But it's really not the same as straw.