Greetings from Zone 5 in Iowa,

Am conducting a bit of an experiment wrt mulching and would like to
know if I'm going about it wrong or what..

I am using grass clippings, layered on in about 2-3 inches at a time,
and am now on the third layer. Here's the problem: weeds are still
coming up through the mulch.

Am pretty sure - not 100% - that these weeds are NOT part of the grass
mulch, since there aren't weeds going to seed in my yard. And the soil
environment under the mulch is, of course, ideal for germinating plants
of any kind. So how much mulch is needed to prevent weeds from coming
up..?

I think the layers have compressed naturally to maybe 2 inches. No
odors evident, the previous layers are a golden straw color. So far if
the weed is big enough I just pull it, otherwise am putting more mulch
over the weeds.

I haven't read the Ruth Stout books, but have heard somewhere she used
TONS of mulch material to conquer (sp?) her weeds. That's a LOT of
mulch, and sounds like more work than just regular weeding. And of
course hoeing and mulching are mutually exclusive activities.

So anyone mulching have a recommendation of how much mulch is needed to
actually control weeds? I've also heard that close planting will
reduce weeds, but my cold frame is planted pretty tightly and I still
have weeds coming through the crop "canopy". Starting to seem like any
technique that promises weed control without hoeing is a bit of snake
oil to me.. Still digging through weed control posts in this
newsgroup, would like to hear from folks that are making it work for
them.

Thanks!