I'm growing mint and some of the leaves have black spots on them and it seems to be spreading to other leaves what are these black spots?

This sounds like some kind of fungal infection, with mint rust being most likely. This causes orangy brown or black spots on the leaves. Some experts say the only 'cure' is to remove affected plants including their root system as soon as you see it or to burn the mint off but this isn't always practical. There are, however some biological fungicides on the market now which may do the trick - cut down the infected mint that's there and destroy the cuttings. you then soak the ground with the fungicide and then spray regularly as the mint regrows according to the instructions on the pack. Actinovate and Serenade are two fungicides that can be used on edible crops.

add some nitrogen to the soil

poop