posted 4 years ago
Welcome to Permies! You're come to a great place to find answers to your questions and share your projects.
I think you have excellent ideas, but whether or not your soil will be ready to plant by April will depend on the weather; this time of year, specifically, the temperature. It's the soil microorganisms that break down the materials to increase soil fertility, but in winter they tend to be dormant. So, stuff doesn't break down much in winter months. I live in zone 7b, and find that cardboard takes about a year to break down enough to need to replace it. Hay or straw take awhile too. I find dried leaves break down the fastest, wood chips the slowest.
A caution about using hay; if it contains grass seed you may be planting yourself a headache. Ask me how I know! If the hay was cut before flowering or going to seed, it should be fine. Straw is supposed to be seedless (remnants of harvested grain) so it's good too.
Your fresh green (nitrogen rich) materials will take awhile to break down as well. Again, especially in winter. The problem is, they require nitrogen to decompose, and so tie up soil nitrogen that your plants need. Well rotted manure would be a better option than fresh, if you can find it.
I know more answers and ideas are on the way. I hope you let us know what you end up doing and keep us posted on your progress.