Whether you are trying to keep people off your property or place of business, the process of stopping someone from jumping over your fence is essentially the same: you need to make it uncomfortable for them to climb the fence. Because there are laws in various cities governing the use of barbed and razor wire and broken glass walls as deterrents, and these types of security solutions are unattractive, you can use natural plantings to keep intruders from scaling your fence. Not only will these plants keep you safe, they will make your unsightly chain-link fence fit in well with your yard's natural surroundings.
Plant Oregon grape holly, cacti (if you live in the west) or Washington hawthorn, to keep intruders at bay, suggests HomeSecurityAdvice.com. Or, plant shrub roses and firethorns, according to WhatHappensNow.com. These plants are covered with thorns and spikes, which will make landing on or climbing over them painful and virtually impossible. Place these plants at 2- or 3-foot intervals, depending on how wide the plants will grow as they age.
Place blackberry vines or pyracantha in areas near your fence where you do not have enough yard space to plant bushes or shrubs. These vines will grow up instead of out and will effectively cover your fence in flowers, sharp thorns and berries (depending on the plant). Two other beautiful, yet thorny, vines are the bougainvillea and the climbing rose. These two plants come in several colors, from white, peach and pink to red, burgundy and purple, and most any in-between color.
Fertilize and water your floral security-guards regularly. The larger and more healthy your thorny bushes and shrubs become, the less likely an intruder will climb on them.