I apply rotted cow manure in the fall and the following spring. The fall application allows the manure to work its way naturally into the ground using the rain, sleet, snow, and the freeze thaw of the winter. The manure feeds the roots over the winter. The spring application works its way into the snow via the spring rains and freeze thaw of the season. And gives the roots a fresh supply of manure to help them get ready for the growing season.
A friend sent this to me. I tend to get started before my neighbors.
I buy the rotted cow manure as early as possible from the store. The frozen bags are easy to carry and don't make a mess in the car. I also buy this at the end of the season for the discount. If you do this, make sure you put them in an elevated place so they don't freeze to the the ground.
I just fill up a bucket and walk around broadcast spreading it over all the beds. No fancy technique needed. I'm old school. I don't wear gloves. I just wash my hands afterward.
From front to rear, peony sorbet, sedum, iris, coneflower, rudbeckia, horseradish
From front to rear, lily, coneflower, phlox, lily, asparagus
From front to rear, coneflower, lily, tree peony, phlox, blackberry red currant
From front to rear, stargazer lily, coneflower, rudbeckia,
Flora Peno lily, coneflower area
From front to rear, coneflower, peony sorbet, rudbeckia, sedum areas
Side yard daffodil and coneflower areas
There is nothing fancy or complicated about this process. But root development is critical for good plants. You see the results, months later, in the summer when the healthy plants are in full bloom. And the work is worth it. Happy Gardening !