I'm NOT a gardener, rarely if ever get out there, but spend about 4 hours this morning in my mom's flower gardens, tilling, raking, weeding, and putting schmutz in the garbage. It was a WINDY morning. After I was washing up, I noticed black in my phlegm and when blowing my nose. Somewhere I read that you can get lung disease from garden dirt. I used saline nasal solution until all was clear, but I'm worried -- is this common? What should I do next? How will I know if I'm sick?
You got dirt in your throat and nose, and those parts of your body are working properly to clear that dirt by making mucus and phlegm and encouraging you to cough and blow them out. Certainly there can be bacteria in dirt, and your immune system may or may not destroy it before it makes you sick. Do consult a medical professional if you're concerned for your health, but if you don't actually feel sick after a few days and the dirt is gone soon, then that's probably the full extent of the problem. This seems to me like the kind of situation where I would call or text one of my relatives who's a nurse and ask her advice, rather than rush to the emergency room for.
In future, protect yourself when gardening in windy weather by wearing a face mask that covers your mouth and nose. Chronic exposure to inhaled particles of any kind is not good for your lungs, so you should reduce your exposure any time you're doing a dusty activity. A bandanna tied bandit-style over the nose and hanging down over the mouth is probably adequate, but if you happen to already own a cloth face mask that will do the job as well. Just make sure to wash it between uses, and expect that it may get stained so don't wear your prettiest one.