Why aren't my potted herbs healthy, and water runs dark out of the parsley container?

Question

I am growing spearmint and flat-leaved parsley in two 10” round containers. I water the plants a couple of times a week, and every 2 weeks or so water them thoroughly until the water drains out the bottom. The plants are not super healthy but they are ok. I keep them outside in an area with a significant amount of sun, but don’t have many locations.

My primary question is: when I water the parsley, very dark water comes out the bottom. Yet the mint the water runs almost clear. Why the difference? Both have been treated similarly, were planted in the same mix, and were only planted around 4 months ago.

Secondary questions: why might the mint be very spindly, and why might neither plant be flourishing?

Photo (note that I’ve removed most of the damaged/unhealthy foliage):

The pots do have a small hole in the bottom, so they do drain.

Answer 1

Wow, that potting mix is far too wet, and while that's probably what's causing most of the trouble, the plants also look like they could stand a good bit more sun. Don't water the plants unless the soil is dry, at least an inch in. Overwatering kills, eventually. You can already see the yellowing and leaf drop. So cut back on the watering, move to the sunniest location you can find, and you should have that taken care of.

Another thing that is good to note is that although herbs don't like super-rich soil, most potting soil has almost zero fertilizing nutrients, so some fertilizing is required for best results. You could use extended release fertilizer, which will last a long time, or you can use multiple applications of soluble fertilizer with some of the waterings. There are also organic fertilizers for potted plants, such as vermicompost tea and fish emulsion, but they may not be as potent.

Edit: I see you've tagged you're question houseplants. If they are indoors, they require some different care than if they are out. Without direct sun. the soil is likely to retain moisture even longer, so watch it carefully and don't overwater. Also, light levels indoors are often too low. Try sitting by a bright window, under a strong cfl bulb, or moving outside for better success.