Parkstrips, those narrow spaces between curbs and sidewalks, are among the most awkward spaces in the garden. In urban areas with significant traffic, they are commonly paved over. Some neighborhoods, especially downtown neighborhoods, do not have parkstrips at all. Suburban neighborhoods though, often have wider parkstrips.
The difficulty with parkstrips is that there is so much happening around them. Cars get parked on one side. Pedestrians pass by on the other side. Driveways need to be kept clear at each end. Water meters and perhaps other subterranean utilities must be accessible.
Street trees are common features in parkstrips. They should have complaisant roots that will be less likely to displace the surrounding pavement and curbs, and high branch structure for adequate clearance above truck traffic on the roadways below. Ideally, street trees should conform with the neighborhood, and are often quite uniform. Selection of street trees should be a community effort where practical.
All other plants that go into parkstrips should be adaptable to confinement within the limited space available. They should not extend over curbs or sidewalks where they can scratch parking cars or be obtrusive to pedestrians. Parkstrip landscapes must also stay low enough so that they do not obstruct the view from cars backing out of driveways.
Because people regularly walk past or through parkstrips, thorny plants like cacti and roses should be kept back from the edges, or preferable not put into parkstrips at all. Large agaves and yuccas (with rigid leaves) are simply too big and dangerous for narrow parkstrips.
Contrary to the trend of planting vegetables in weird places, parkstrips are not good places for them either. The main problem is what dogs like to do in parkstrips. The second problem is that the good produce that might be out reach of dogs is within reach of everyone else walking or driving by. Reflected glare from all the surrounding pavement is a problem for plants that do not like harsh exposure.
Really, there are far more limitations on parkstrip landscaping than there are options. Turf grasses or tough ground cover that tolerates traffic, like trailing gazania, may seem to be a mundane, but they are practical. At least ground cover can be punctuated with clumping perennials like African iris, lily-of-the-Nile or blanket flower.