Along with super strength, the primary quality that makes zombies dangerous is their acute sense of smell. A zombie’s olfactory sense is attuned to detect living flesh and free-flowing blood; also, the scent of fear. These scents can rouse a zombie from a motionless stupor into a frenzy of shambling, slavering hunger. The living dead disregard all other scents, so don’t try to soothe them with lavender oil. The best way to use aromatherapy against zombies is to cover yourself with the scent of death. This way you will blend in with them.
A good place to start is with Amorphophallus titanium, commonly known as the "The Corpse Flower of Sumatra." This plant grows primarily in tropical regions, such as Sumatra. Order yours locally at http://www.boulderblooms.com. Don’t worry if you have a brown thumb – despite being tropical, it’s easy to care for, and having one around will turn your territory into an olfactory fortress against the undead.
If you are unable to order The Corpse Flower of Sumatra from Boulder Blooms, there are many other plants to choose from. Try introducing Rafflesia (also incidentally from Sumatra) into your home garden, but only if you are willing to risk losing said home garden. This plant is parasitic and will suck the life out of other plants. Try grinding the blooms into a fine powder and adding a little olive oil to create a simple, effective perfume.
If you can’t find either plant, or you are allergic, try Smilex or Nemexia. They’re not as powerful as their tropical counterparts, but are more readily available in the Boulder area, and they emit a foul rotting-meat smell. You could also give yourself a good rub-down with actual rotting meat.
TAKE NOTE: These fumes mask the scent of living flesh, but beware! This tactic may backfire, as zombies have been known to smell through the ruse, and, covered in the stench of death yourself, you will not be able to smell the dead coming. Also, invest in fly-paper.
If all of these suggestions still fail you, take a trip to the friendly people here: http://bouldercountygold.com/2009/services-faces-places/best-funeral-home-service-provider-crist-mortuary-crematory. If you explain your situation and come prepared with equipment, they should be able to help you out.