A really thick layer of straw over the bed will work.

I use shredded tree branches because I have them for free.

I usually put newspaper down before i mulch. then it's easy to pull everything up and compost it. no weeds and no more than an initial hour or two of work.

Thank you---that sounds much easier to deal with in the spring than straw or wood chips---I've tried straw and get a ton of new weeds (it's always full of seeds, in my experience) and the free wood chips around here are very coarse (much more coarse than purchased shredded mulch) and wouldn't be my choice to leave in the garden when I plant in the spring. I'll start stocking up on newspaper---thank you!!

Ann

Straw and HAY are not the same things.
Hay is grass cut and baled and as you say is usually loaded with seeds. Straw is the stalk of a grain crop and is mostly seedless. It needs to be put on thicker though because its stalky stuff and you need more stalks to make coverage.

Put down several layers of newspaper, wet it, then cover with leaves, grass clippings, whatever to a depth of 3-4 inches. This will decompose over the winter and in the spring, all you have to do is pull away where you want to plant and leave the rest.