JHB, cilantro is a cool season herb. I see you are in 10a, so you may want to plant it in late October and let it grow during the cooler months. Here in central Texas cilantro is just finishing up--as soon as the daytime temperatures hit the mid-80's and nighttime in the 70's, cilantro is done.
Some of our parsley is getting ready to bolt. It changes color a bit--gets darker green--and that's a sign that it wants to set seed. I harvest as much as I can, chop it fine, add just enough water to make a paste, then freeze it in tablespoon size blobs on waxed paper. When frozen, I transfer to a freezer container and the parsley can be used in cooking for the rest of the year.