Delete rows with blank values in one particular column

I am working on a large dataset, with some rows with NAs and others with blanks:

df <- data.frame(ID = c(1:7),                                   
         home_pc = c("","CB4 2DT", "NE5 7TH", "BY5 8IB", "DH4 6PB","MP9 7GH","KN4 5GH"),               
         start_pc = c(NA,"Home", "FC5 7YH","Home", "CB3 5TH", "BV6 5PB",NA),               
         end_pc = c(NA,"CB5 4FG","Home","","Home","",NA))

How do I remove the NAs and blanks in one go (in the start_pc and end_pc columns)? I have in the past used:

df<- df[-which($start_pc)), ]

... to remove the NAs - is there a similar command to remove the blanks?


 df[!($start_pc) | df$start_pc==""), ]