My wife uses a granule type fert that work when they get rained on or watered, that could help you out some. We use MG on the veggies since we have landscape fabric over the garden.
/johnny
OH yes! For the first shot of MG, I used the amount for regular-feeding indoor plants, since mine are outside pots.
Then I remembered the stash of Osmocote I had, and spread that around a bit a couple of days later.
I bought some landscape fabric, but have not put it into place yet. I was thinking to put it around the rose bushes since we have a lot of grass/weeds there, and Darlin’ is reluctant to edge too close to them!