2 years into a new home, I’ve noticed the Azalea shrubs planted before we moved in have been showing less green growth and less flowers. Tested the soil and found it was very neutral, which I have started to correct with soil acidifiers (Espoma). I’ve noticed some branches will still flower and produce leaves, while others will not. These branches also show signs of lichen development.

My question is - should I assume these non-productive branches are dead, or wait until I get the soil acidity right for at least a season before pruning them off?

Azaleas do prefer an acidic soil down towards pH 6. Soil acidifiers work as will quality organic matter which benefits the plants and the soil structure and will be more long term than chemical acidifiers. Peat moss, mushroom composts, composts from a compost bin or pile works well. Lichen is more of an environmental indicator than live or dead tissue. You can lightly scrape the bark on the twigs to determine live or dead. strong live twigs will have a solid dark green color and appear moist looking. dying branches will have a light green and dry looking appearance below the bark. dead will be totally brown and easily snapped in two. anything dead can be removed.

do not expect an immediate turn around, getting plants healthy again will take a couple of growing seasons