I'm not sure I understand the question.
You purchased a roll of landscape fabric and you're wondering what to do with it? Is that right?

-Diggity

I would point you back to the store where you bought the plastic so you can return it and buy real mulch. If you can put a couple inches of real mulch down, the weeds should have a tough time getting up through that. Even if they do, the softness of the underlying soil will make it easy to pull them.

Trying to put that landscape fabric around existing plants us usually a pain in the ...... The amount of holes and seams you wind up with often let weeds through anyway and I've had plenty of weeds that are strong enough to grow right through the stuff. I also notice a tendency where the fabric is used, people seem to think that simply hiding the fabric with decorative mulch is enough. If light is getting through, then seeds can germinate above the fabric and grow roots down through it or weeds below the fabric get enough light to search for a hole or punch one themselves and come up. Also with fabric down you can't really rake or hoe without messing up the fabric. If you just put a thick layer of mulch and you get little weed seeds sprouting in it, then rake or hoe it around a bit and most of those little weed seedlings are done for. Grass is another matter but the fabric still doesn't seem to help me there either.

How about if i tried to remove as much of the grass etc...before I mulch. I used some of the fabric around my zebra grass ans have just found some new growth that went to the send of the fabric and poked it's head up...Thanks for all the ideas. I think I will go to the book store and find blooming for idiots....

Many grasses really like well mulched soil and will grow in there unless there is something to stop them from sending roots into that nice moist soil that after a time will be full of nutrients those same grasses need to grow really well.
Clean the grass out of the planting beds and put down a barrier to stop the roots from reenetering, then plunk down your mulch, 4 to 6 inches are really needed to suppress "weed" growth, aid in soil moisture retention, and aid in soil temperature control.

Thank you!!!

I usually start mulching with a wheelbarrow full of wood chips and a shovel.

Hi Greg,

I usually start a flower/veggie bed area 6 months to a year before planting anything. I put down paper bags or cardboard, leaves and any other organic material I can get my hands on then top all off with a thick layer of shredded mulch. I leave the area alone for 6 months to a year then plant.

Sounds like you started the planting process already though. I'm not a fan of weed blocking fabric except in some very rare situations. I've never had a good experience with the weed block in any situation that I wanted plants to grow.

It might be a pain but can you fold up newspaper to fit around your existing plants and then put a few inches of mulch down? Labor intenive probably but, depending on what grass you are trying to control, it is how I would handle the situation.