The cardboard will smother the leaves but i think you need soil or lasagna lyers in top of the cardboard to plant into. otherwise, i don't envy you the job of cutting thru the landscape fabric, cardboard and remains of the sod rootmass to try toplant int the spring - that won't fully degrade in our cold winters.

I have started almost all of my garden beds in this manner.

I cut the grass short. Cover with 5 or 6 layers of newspaper, add 4 - 5" of farm post and then plant.
I plant by pushing back the farm post, cutting the newspaper I then put in my plants, tuck the newspaper around the plant and put the farm post back.

You will get weed seeds blowing in and growing on top of the newspaper, landscape fabric, cardboard or whatever but they are easy to control.

Last fall I ended up getting a bed ready for spring by covering the area with black plastic for 4 weeks, taking it away and then adding the newspaper and farm post. I have also planted the same day I got the bed ready.

It is dead easy.

Farm post is manure and straw ground together and aged. I get mine for free from the Canterbury race track in Shakopee.

Good luck.

Zenpotter,
Just where at Canterbury do you go to get the farm post?? What do I need to know or who do I ask? Is it plentiful or only available sometimes?

I, too, have some new beds that could use some of this.
Thanks!
Mnzinnia

Thanks for all the great information. I have access to a ton of cardboard every Friday, so I may start this weekend. Also, it seems all the shrubs are super cheap since it the end of the season, so it might be a good idea to get started planting with what's available. I, too, would love to know where I can get the farm post at Canterbury or any place that I can get good, cheap topsoil in the TC area.

I have had excellent experiences with cardboard on grass and wood chips on top. I leave the grass long--that adds some moisture and provides a good balance of nitrogen:carbon for decomposing the whole lot.

I advise against landscape fabric.