Q.Nitrogen in Mulch in Layer Garden
I’ve made a lasagna or layered garden in which I have planted into right away. My layers are cardboard, straw, newspapers, cypress bark, straw, ashes from my fireplace, chicken manure compost and some topsoil. I’ve dug little holes and set the plants in with their existing soil and a little more of bagged potting soil. The plants are doing fine so far, but will all these layers steal some of the nitrogen away from my veggie plants? I have yellow squash about 6 inches with blossom end rot. Does that have anything to do with this layering method?

Certified GKH Gardening Expert
The chicken manure compost should provide enough nitrogen to offset the decomposition process. Blossom end rot is caused by a lack of calcium, so it's probably not caused by this method. To tell the truth, it is an indicator that you may have too much nitrogen, but most likely it's simply too little calcium. This article will help:
https://www.gardeningknowhow.com/edible/vegetables/squash/squash-blossom-end-rot-causes-and-treatment.htm