Why am I sheet mulching again?

So I am going to do a no dig garden for the spring. I was going to just put a couple layers of cardboard over the existing lawn, then cover with 4" of compost. Then I was going to plant right into the compost. My question is: do I need to worry about the existing lawn growing through 4" of compost? It can't grow if it's not getting sunlight right? Also, people say you lay down cardboard to snuff weed/grass seeds....is your typical suburban lawn seed really have enough energy to push a grass seedling all the way up through four inches of compost? That would be like planting your lawn 4" deep!

Adam Buchler wrote:My question is: do I need to worry about the existing lawn growing through 4" of compost? !

Yes (once you water, the compost will settle between the blades if nothing else)

Adam Buchler wrote:It can't grow if it's not getting sunlight right?

Wrong (the force is strong in weeds, especially if you have some that spread by rhizomes. Let us not discuss bindweed.)

Adam Buchler wrote:weed/grass seeds....is your typical suburban lawn seed really have enough energy to push a grass seedling all the way up through four inches of compost?

Yes (a foot of organic material would be better. Dry leaves, moldy hay, bedding from a stable or coop, whatever you can get. It will sink down in short order. If you have no objections to a nitrogen inputs like blood or alfalfa meal, put it down on the grass, then the cardboard. Water between layers. If I had nice compost, I would save it for the top layers.)

Ann Torrence wrote:

Adam Buchler wrote:My question is: do I need to worry about the existing lawn growing through 4" of compost? !

Yes (once you water, the compost will settle between the blades if nothing else)

Adam Buchler wrote:It can't grow if it's not getting sunlight right?

Wrong (the force is strong in weeds, especially if you have some that spread by rhizomes. Let us not discuss bindweed.)

Adam Buchler wrote:weed/grass seeds....is your typical suburban lawn seed really have enough energy to push a grass seedling all the way up through four inches of compost?

Yes (a foot of organic material would be better. Dry leaves, moldy hay, bedding from a stable or coop, whatever you can get. It will sink down in short order. If you have no objections to a nitrogen inputs like blood or alfalfa meal, put it down on the grass, then the cardboard. Water between layers. If I had nice compost, I would save it for the top layers.)

I actually did put down some manure and blood/bone but Just because I had some around. For what reason are you suggesting it?

The cardboard is your friend here - it will block cracks that your weeds and grass will otherwise break through. Try to do you mulching a few months ahead of your planting season - that way most of the plants beneath will have died off already and started breaking down.

Also, if you have limited material to work with do one area really well, rather than trying to stretch it over a larger area. Personally I'm aiming for cardboard, +1 inch of compost, +6 inches of woodchips. It seems ready to plant through in about 6 weeks. This is going straight on top of a lawn area.

Michael Cox wrote:The cardboard is your friend here - it will block cracks that your weeds and grass will otherwise break through. Try to do you mulching a few months ahead of your planting season - that way most of the plants beneath will have died off already and started breaking down.

Also, if you have limited material to work with do one area really well, rather than trying to stretch it over a larger area. Personally I'm aiming for cardboard, +1 inch of compost, +6 inches of woodchips. It seems ready to plant through in about 6 weeks. This is going straight on top of a lawn area.

Well I was going to do cardboard, 4" compost, and a light mulch for now because I'm in NJ and I don't want to delay warming the soil. I figure with a light mulch it will still warm the compost and I can just plant right into the compost. Sound reasonable?

Adam Buchler wrote:
I actually did put down some manure and blood/bone but Just because I had some around. For what reason are you suggesting it?

Toby Hemenway says it's good for the worms. I'm not sure about that, but cardboard is so carbonaceous, it stands to reason that a little nitrogen would help it break down after its smothering work is done. The hard part here is getting and keeping everything wet until it gets settled in.

Why am I sheet mulching again?

So why are you sheet mulching again and which method did you use instead of sheet mulching?

Putting down a thicker layer of matter is essential in keeping the weeds out. The cardboard will do a lot for you, but weeds are wild and they break through! It would put at least 10 inches of compost, manure, straw, whatever you can find. Sheet mulching has been very successful for me in California and Missouri. It's fabulous!

Desiree, what do you have under the sheet mulch - something which can be called topsoil or soil?