natural surveillance

territoriality

plant selection

maintenance

The broader issue of "what" role landscapes can play in restoring order (i.e. fixing broken windows) was addressed earlier in Background: When Good Spaces Go Bad. 

The presence of vegetation has been perceived as a "crime generator" for a long time. The earliest humans had to keep a watchful eye for predators that would use vegetation for concealment. One of the earliest documented cases of law enforcement's distrust of vegetation can be traced back to England during the rule of King Edward I. King Edward ("Long Shanks") enacted the Statue of Winchester in 1285 to eliminate areas of concealment provided by vegetation and ditches along highways connecting market towns. The statue called for a 200 foot zone, on either side of the road, without vegetation and ditches "whereby a man may lurk to do harm" (BBC, 2002). The landowners along the highway were responsible for not only removing vegetation and ditches but were also responsible for crimes that may occur on the road due to negligence in not removing potential areas of concealment.

Landscapes can work for and against CPTED. 
Landscapes can work against CPTED when there is poor plant selection, installation, or maintenance. A landscape in disrepair gives the impression that the owner is absent and/or doesn't care. The vegetation in a poorly designed and maintained landscape blocks natural surveillance and provides areas of concealment. 

Landscapes can work for CPTED by supporting the core components: access control, natural surveillance, and territoriality. In order to create a landscape that aids in CPTED it's critical to select appropriate plants, install them in appropriate places, and to stick to rigorous maintenance on a regular basis. Additional information can be found on plant selection and maintenance by clicking on the links located in the left panel or on the CPTED home page.  

There are additional benefits resulting from property owners retrofitting their landscapes to support CPTED. The property owner should be able to experience some immediate success since some of the pruning strategies are relatively easy to implement. Compared to other CPTED strategies (i.e. installing locks and doors), making changes to the landscape can be relatively inexpensive and it's something the property owner can do immediately. Participation makes the homeowner an active participant in CPTED and gets him thinking about the process.

Build it and they will come...
Citizens are more likely to claim ownership and utilize spaces when they "want" to be in that particular space. Therefore, it's important that these spaces are recognized as being pleasing and comfortable by the intended users. Well designed and maintained landscapes have proven themselves very capable of providing attractive and inviting outdoor spaces. Limited landscaping resources can be concentrated in certain areas deemed strategically important by crime prevention specialists.

Make it comfortable...
Deciduous trees cool areas inside and outside of buildings. Landscaping can help to block or channel away unwanted noise. In addition to creating more pleasing sounds (leaves rustling and bird songs). Naturally, plants can be selected that produce blooms or present outstanding colors of foliage throughout the growing season. The ability of plants to generate pleasing smells may be particularly useful to mask unwanted odors (i.e. public restrooms and dumpsters).

Here are a series of images from Urban Advantage showing the potential for typical urban settings. In each series, the first image is the true image. Steve Price (Urban Advantage) then makes modifications to the original image (descriptions below) to illustrate the potential. [Images are thumbnailed. Click on the picture to enlarge.]

Existing conditions (23rd Avenue, Oakland, CA)	Building facelifts, restoration of ground floor retail, infill development	Street resurfaced, new sidewalks	Addition of street trees and street lamps	Open businesses, patrons!
Existing residential street	Addition of street trees and street lamps; streets narrowed and resurfaced;	Introduction of mixed housing	Existing urban creek (Richmond, CA)	Creek restoration, regional bicycle path, development that exploits creek as amenity
Many thanks to Steve Price at Urban Advantage for the use of the above images.

British Broadcasting Corporation. 2002. Last accessed December 15, 2002. www.bbc.co.uk/history/state/monarchs_leaders/edward_i.shtml

Price, S. 2003. Personal communication. Urban Advantage March 24, 2003. www.urban-advantage.com