How to kill trash grass and weeds in fairly new Azalea bed

I planted a couple of new young azaleas 8 months back and I've been trying to keep up with keeping the trash weeds and grass from growing up in the bed. Can I spray anything that will kill the trash but not hurt the azaleas? Getting on my hands and knees and pulling out tiny sprigs of weeds and grass is getting tedious every couple of weeks. I tried mulch but that doesn't seem to work and I'm kicking my own arse for not laying down some kind of barrier first but I think it's too late I don't want to disturb the azaleas to put down any kind of barrier material