Fertilizer will encourage fast growth that could encourage fire blight. Happened to me last summer after applying a triple 19 around my 3 yr old trees. I won’t do that again
You can also cut unlimited dogwood cuttings from a ditch or next to low areas immediately after the frost is out. Use a 1/4” steel rod with a handle,push down at least a foot in the soil,put your cutting in and heel in. Good luck