Not all Deer Repellents work the same, but some will tell you that they all do the same job. There are methods and concoctions that are more of a myth than a fact, but if you can make something that will annoy most humans, odds are that it will annoy a deer.

You can find Liquid bittering agents that make your plants less edible to the deer, but they can be quite expensive and may need reapplication often in rainy climates.

Physical barriers and scarecrows also work, but there is always the chance that the deer might still damage the plant and there is a higher lvl of difficulty to apply the protection.

Odor repellents such as Milorganite work, but are not recommended for areas close to human habitation. Your tomatoes won't be eaten by the deer, but you may not want to eat them either... or go near them for that matter.

My parents have went through quite a bit of this battle, and I can honestly say that all deer repellents work. Not all of them fit our lifestyle though. Constant Gardners who tend to their gardens more than a few times a week should have no qualms with reapplying the spray repellent in a timely manner. Less active gardners may want to use netting or a scarecrow which takes longer to set up, but will give the plant owner a peace of mind vs. deer eating their prized petunias while they are off at work.