Plants grow, so plan ahead

Thuja plicata (RedCedar) hedge

This photo portrays an excellent example of a short sighted landscape design.  This RedCedar hedge is planted 1'-0" from the public sidewalk, and on 3'-0" centres, or 3'-0" apart.  There is not a hedging shrub in cultivation that should be planted 1'-0" from the sidewalk, because every plant needs space to grow.  However, RedCedars in particular need a lot of space.

For instance, RedCedars grow in the wild to 170-250' (50-70 meters). One of the features of a red cedar is its buttressed trunk which can be 6'-0" in diameter at maturity.  Although these cedars will never reach those dimensions, they will easily and quickly form a hedge 6'-0" deep and 10'-0" high.

My guess is the homeowner requested an inexpensive, fast growing hedge for privacy. The RedCedar hedge will definitely provide privacy for the homeowner quickly, and it is the least expensive of hedging shrubs.  But the hedge will not stop growing once it has provided the privacy;  the hedge will continue growing for years, and for years the homeowner will have to pay to have this hedge trimmed.

Hedges that are repeatedly pruned hard become stressed.
Hedges that grow beyond their required height are
expensive to remove.

All formal hedges have to be trimmed regularly to maintain shape, width and height.  But when a hedge is planted so close to a public sidewalk, the public's right of way becomes an issue.  There are also often municipal issues of not obstructing an area within 2'-0" of a public sidewalk, and in this case, site lines at an intersection.

Even with pruning, the trees in this hedge will continue to grow in girth, and the trunks and roots of the RedCedars will eventually lift the public sidewalk, making it uneven.  The solution to levelling the sidewalk may be to remove the concrete, cut all the roots of the hedge, and re-pour the sidewalk.  This will be a solution for the sidewalk, but not a solution for the hedge.

A better solution is to choose an appropriate hedging material during the design process. The appropriate hedging material may be more expensive initially, but will be cost effective during its lifetime.