Cardboard and mulch

Hi total noob here- I’m working on a 25x12 foot garden plot. Was grass and weeds, in the fall I laid cardboard and a couple inches of mulch. It is not nearly as broken down as I thought it would be by now and I’m not sure my best course of action for planting in the next couple months. Tear it all up and disturb the mycelium and bugs? Dirt on top? Rake out the biggest chunks and plant in what’s left? Will just be planting fairly classic garden veggies/herbs/flowers for now, soil underneath was pure red clay

Where I live, I just add a little more compost depth and plant into it even if the cardboard hasn't broken down. The roots find a way through. If you're talking about carrots, that might not work out ideally, but most stuff would. That's here though and the cardboard never survives two years.

Welcome to Permies!

It sounds like you started the first steps of a "lasagna garden". You may want to learn more about that technique and further enrich your soil.

You also might build a hugelkultur bed there too.  We have done both and they both worked, but the hugelkultur has needed less manure/fertilizer etc.

Best wishes!

My suggestion would be to just cut a hole in the cardboard leaving the mulch on top intact.

Dig a hole, add some compost, and put in your transplants.

This would probably also work for seeds.

Welcome to Permies.

I am a devotee to deep mulch and its effectiveness in my climate. You need enough mulch material to be keeping a layer of moisture underneath and in that cardboard layer. That will lead to it breaking down faster. If its too dry, it just sits there.

Another option that would be simplier/faster to get you growing is 'punching' holes through the mulch and cardboard to plant into. You might have to spot pull a weed or two but you should still get the benefits of that mulch/smother layer. I have a bulb planting auger bit for my drill that worked for me.

I think that the decomposition process works much slower in the winter than the summer, so I'm not particularly surprised your mulch is still breaking down. What was your mulch material - leaves, wood chip, other organic matter? Different materials will obviously break down at different rates.
It depends also on what sort of weeds you had underneath - persistent perennial weeds like bindweed or creeping thistle will probably come back and stronger tap rooted ones will punch through several layers of cardboard here quite happily .
I think like Christopher I'd be inclined to see if I could get more compost and maybe cardboard. Charles Dowding puts about 6 inches of compost down to smother his weeds (although I don't think he uses cardboard) so the thicker the layer the better (particularly with clay soil). Maybe you could rake some of it up to make a thicker layer on part of it and plant early crops in that, and work on building up the rest of the area for later planted seeds. If the mulch really is rather woody then more compost on top or possibly adding more nitrogen rich material (like grass clippings, coffee grounds, urine..) first to help break it down more quickly. It's early spring yet, so I wouldn't panic.

I fight Bermuda grass and morning glorious, so I put cardboard down and try for 8 to 12" of wood chips. When I want to plant in this area I would pull back the wood chips in a cone or cylinder shape. I fill up the hole I made with organic compost, and plant. I have had very good luck using this method. The only downside is I had to add wood chips every year. I can't plant this way anymore because gophers eat everything.
Good luck to you.