My soil has too much of every nutrient except nitrogen, of which it has close to none. I have been adding blood meal to the soil. The internet states it is fast acting IF the soil is warm. Mine is, so:
1. How soon will I see a difference?
2. Can blood meal be put in a hose sprayer and sprayed right on the plant?
Bloodmeal is not soluble so would probably clog any sprayer.
Worked into the soil around plants---it probably will take a week or two before you see results.
It has to break down before plants can use it.