If they're not doing well, it may be an indication that their soil and pots are not draining well enough. Both need very well draining soil--more than a normal potting mix does. I mix bonsai or succulent soil in for mine, then water when the tips just slightly droop. If I'm around, I do move them in if I know there will be a lot of rain (and this year we've had hail near weekly). But, if I'm not home, then I'm pretty confident that they'll drain fine--I just make sure to really check them before watering again.

It's odd that you are getting mould. That indicates something very wrong going on. Do the pots have drain holes? Even in my wet climate it is almost impossible for a plant in a pot with adequate drainage to get too much water. The surface area just isn't great enough to catch that much. I'd be taking them in and out several times a day for much of the year.

Is it possible that it wasn't mold, but a mineral buildup that was leaching to the top with the watering? I know here terra cotta pots immediately start collecting salts and minerals from our water.

Hey everyone! Thanks for the replies! I'm not really sure if it is actually mold or not. I water my herbs after the sun goes down so I am wondering if I need to change the time from watering in the evening to watering in the mornings? My mom has always told me to water them when the sun won't hit them so it doesn't burn the leaves. The sun doesn't get around to the side where my herbs are until about 1:00 in the afternoon. All my pots have drain holes in them but I guess I could make more just to be on the safe side. I really don't know if it could be a mineral build up because I have no idea the difference lol. I am attaching a photo of what I am talking about everyone. Hopefully with your expertise you guys can help me out. Thanks again everyone