Question
I recently bought a house that had been a rental for many years. Most of the people were, bluntly, not very clean. The soil off the front stoop STINKS! Is there anything I can plant that would help draw the aroma out of the soil? I rather not have to remove the dirt, because we live in the city, and it would just have to go somewhere else. Or will time take care of it?  Thank you for your time in answering.

Answer
Hi Cathy,  Look for a bag of Hydrated Lime.  Follow the instructions and dust the area with it.  It does an excellent job of neutralizing odors. Don't use too much if there are plants in the area because it will rapidly raise your pH.  No plants...no problem.  I would recommend wearing a dust mask, it can irritate you nose.  
You might consider cedar mulch also to help mask the odor. Jim