For extra security, thorny and spiny plants can be planted around the home where intruders might enter, such as under windows. Also, plants that repel trespassers can be used to prevent foot traffic if you live on a corner and people take a short cut across the corner of your yard. When planting spiny or thorny plants, use extreme caution because they can cause eye and skin injury. Some intruder prevention plants are dangerous around children and pets because of their spiny thorns or leaves.
How to Use Plants for Home Security
Locate a place around your home where an intruder could take advantage of the space to enter the property or home. Places to plant security plants are by a privacy fence that can be jumped over, beneath a window, in an area with access to the street that you don't use often, or a dark area of the yard that receives little light in the evening.
Choose plants for security that have thorns or spines that repel intruders such as hollies, agave, spiny cactus, stiff yuccas, citrus trees, rose bushes, or thorny vines such as blackberry vines or pyracantha.
Plant thorny or spiny plants with the tallest plants in the back of the area where they will be observed. For example, place the tallest plants against the wall or fence and lower plants in the front. Use care when planting intruder-proof plants because you can injure yourself in the process.