@annabel_di ...
To ATP ...
Your plan is just fine. Roses love horse manure. There is no need to till it into the soil. The longer it is out there, the longer Nature has time to decompose the manure further and rain will leach nutrients into the soil.
The soil in my garden in the mountains of northern California has improved from dead soil to active soil just by putting organic material on top of the soil and I have never tilled the soil.
