Tension cable should be considered when installing deer fence for several reasons. For one, fence posts that are spaced over 15 feet may see sagging of the fence material between posts. Secondly, if trees are around the premises that may see fallen branches; and lastly, when gardens are located in windy areas [where tree branches and flying debris may become problematic].
While 12 gauge tension wire may be enough to secure the top, middle and/or bottom of a plastic deer fence, steel core tension wire may be of more interest to homeowners that experience troubles with trees; debris; and even aggressive deer herds approaching landscapes. Steel core tension wire is made from 8 gauge steel that is virtually chew-resistant to fight off deer and small critters. The black PVC-coating also extends the longevity of the steel core by protecting it from weather exposure.
For homeowners that grow plants in areas with a lot of trees around the property, and worry about large deer herds passing through, consider using steel core tension wire to secure deer fences.