I am trying to get some fresh herbs (Parsley and Dill for example) to stay fresh for some time. I have tried the water jar method which is just trimming ends of stems and putting the bunch in a jar of water. Parsley seems to survive this perfectly for over a week. But for some reason Dill gets  ilted after couple days.  My concerns are: 1) What is causing wilting here? 2) If I added some fertilizer to the water inside the jar, would that keep the herb alive? 
There are some kinds of mold which are safe to consume (blue cheese is a common example) but in general they are not. While you might often be fine eating a bit, there's no guarantee, so to be safe you should throw out moldy food like your jerky.  See the FDA's advice, for example.  Note that mold is okay on some kinds of cured meats:     Hard salami and dry-cured country hams: Use. Scrub mold off surface. It is normal for these shelf-stable products to have surface mold.   But I'm not sure it's normal for jerky. For those examples it's normal and even common to have mold, but for jerky it's not common, so I wouldn't be confident it's normal. (Indeed, it grew there when you left it somewhere moist, so it's not part of the normal production and storage of jerky.) Additionally, jerky is generally more fibrous and less solid than those things, so there's more potential for mold to grow inside it, where you wouldn't be able to scrub it off.  Your example does look like it's mostly on the surface though, so if you want to take a small chance, you could see if you can really scrub it all off. 