My flat leaf parsley is not looking very healthy; the growth seems stunted, and the leaves are starting to turn a pale red. What should I do to revive it?
Parsley forms a tap root; it looks like the soil in your pot isn't very deep, so the root might not be developing properly. You might be able to carefully lift the plant with root ball intact, put some more soil underneath it, then replace the plant. This would give it the root some more space to develop.