Generally the life expectancy of a garden is 12-15 years. Trees grow and foundation and other mid sized shrubs out grow their area. This is a natural and to be expected evolution of your garden. Some plants have a garden life expectancy of 10 – 15 years. Examples include azaleas and roses. Others have life expectancy of only 5-8 years Euryops is an example

Where to start

Make an inventory of the plants and trees in the garden looking for overgrown plants that can be reshaped into different uses
One of the most disconcerting things is to go into a 30-year-old garden and find everything stripped out before I come in.
When I go in I look to see if shrubs can be recycled into tree like elements.
Is the problem growing things there caused because what was in the sun in now in the shade.
Are planter beds just too small? This is a common problem. 3’ planters were common in the 50’s and 60. Often the solution is a complete redesign of the planting beds.
Are there plants that were surfaced pruned that can be rescued by natural pruning?
Is everything pruned at the top of a 6’ fence and can that be corrected?
Look at planter bed sizes and shapes

Look at changes in uses required
Old owner with children gone
New owner with children
Are new lawn and planter bed shapes needed?

Is the view from the house attractive year round and is there some change as the season’s progress.

As I design I try to keep- some design concepts in mind.

Layer the garden using negative space. This means a mix of sizes with good separation between the layers.

Look for seasonal interest in the garden

Make the planter beds of a size to hold the plants.

Don’t chose plants that we know are just too large or with the wrong growth pattern for the spot.

Look to find or create focal points.
Interesting shrubs or trees,
` Water feature
Arbor
Trellising
Art objects

Look at what kind of maintenance the client can and Will do.

a wonderful garden that your neighbor can maintain is not a success regardless of the inspiration in creating it.