Don't mulch where you have sown seeds, it will prevent them from germinating.

I think it will depend on what seeds you are planning to seed. But I usually wait till everything is sort of up and growing before I mulch.
Sarah

IF your soil temps are high enough for germination and growth - you don't want to mulch until it is - you can mulch the whole thing, then pull the mulch 2-3" back from the rows where you will put the seeds, plant the seeds. Once the seedlings are 2-3" tall, slowly replace the mulch up to the sides of the row of plants.

Pine straw is a good mulch - we use it sometimes too - but it is acidic and it does take more time than other mulches to decompose so be sure to keep it away from direct contact with the stems of the plants so it won't bind up any nitrogen that they may need. OR you can layer on the pine straw and then add additional fertilizer by just scattering it over the mulch.

Dave

Thank you :-)