To keep algae growth from your bird bath drop some pre-1982 copper pennies in. I have what I would call a normal size bird bath & I use 7 pennies. The reason for the pennies being pre-1982 is that before that year, the pennies contained copper, a natural algicide.
Wet newspapers and put layers around the plants overlapping as you go; cover with mulch and forget about weeds. Weeds will get through some gardening plastic; they will not get through wet newspaper. Good composting!