Research has shown that Avid and Heritage together is an excellent combination of products for turf care, giving you both insect/nematode and disease control for overall turf health. Sometime specific products will have extra plant health boosting properties that can be hard to determine. The Avid + Heritage Multipack includes the Heritage WG (wettable granules) and Avid 0.15 EC.
We would suggest using Heritage G Fungicide by itself then you can use a fertilizer afterwards by a few days or even a week to not overload the lawn with chemicals.
Heritage Fungicide does not have any insecticides in it so it should not harm butterflies or birds. If you would like to take extra precaution you may apply while they are not in the area as it will not reactivate once dry
Heritage Fungicide is applied at 4-8 fl oz per acre in 100 gallons for rose blackspot. This generally breaks down to 0.04-0.08 fl oz per gallon. Please refer to the product label for complete instructions.