Repellents provide effective deer control when they are regularly applied to vegetation. However, rainfall removes repellents from the vegetation, requiring periodic applications. Changing repellents every few years on each site has been demonstrated to improve repellent effectiveness. The potency of repellents may vary from year to year, and from neighborhood to neighborhood. When deer numbers approach biological carrying capacity, repellents may be totally ineffective.
Fences create a barrier between deer and the protected vegetation.
In situations where deer pressure is moderate to high, or the value of the growing stock is high, physically excluding or deterring deer from growing areas using fencing may be a necessity. Many designs of electric and non-electric fences may be used. Barrier fences are more costly than electric ones. However, electric fences are inappropriate where high human contact is likely. Regular inspection and maintenance of fences increase their effectiveness.