Hey there, I recently added about 2 buckets of chicken manure in my garden, which is about 2x3.5m big. The manure had some hay in it, and a couple weeks prior I put some aged horse manure in. I was hoping to improve it as it has quite a bit of clay soil. I recently found out the fresh chicken poo may be harmful to plant leaves and that it should be aged or turned into "tea" first. Is there anything I can do to help it break down or anything else I can add in now that the chicken manure is already in it? I was wanting to plant for the spring. .
It takes six to nine months for chicken manure to compost so you probably shouldn't plant before May. Also, to speed things up, turn the soil in your garden bed as you would a compost pile. That will help aerate it and keep the microorganisms working.
https://www.gardeningknowhow.com/composting/manures/chicken-manure-fertilizer.htm
I just scattered 9 inches of horse manure/straw mix on future garden site (next spring). Should I till it in now or wait until spring?
The decision to till before winter or after depends on factors like weed control and soil aeration. Tilling before winter exposes weed roots and enhances soil aeration, while tilling in spring preserves soil structure and avoids disturbing beneficial organisms. When incorporating manure, it's generally beneficial to do so in the fall before winter, allowing it to break down and enrich the soil over the dormant season.
This collection of articles will offer more information on preserving your soil health:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers
We have garden boxes 4’ x 4’. We didn’t have access to soil so we filled the boxes up with tree branches and manure. Then put about 2 inches of potting soil on top. Can we get e-coli from the roots of the plants touching the manure?
If the manure was not composted, you should avoid harvesting vegetables for at least four months. A better scenario would be to put it down in the fall or winter for a spring garden. But composted manure is best because it eliminates weed seeds and disease pathogens if it is heated to 140 degrees F for a sustained time. Here is more:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/using-fresh-manure-in-gardens.htm
https://www.gardeningknowhow.com/composting/manures/manure-pros-cons.htm
https://www.gardeningknowhow.com/composting/manures/the-benefits-of-manure-in-your-garden.htm
Even using that much manure, if it was composted, could make the garden too rich and not appropriate for the flowers or vegetables you intend to grow. If you now have access to soil, you could add some garden soil to the mix.