The crime is… not knowing what your plants will grow up to be! Most of us buy our plants in their infancy and we forget they will grow up! This is where good planning comes into play. We all go to the garden centers with great aspirations of being the "Yard of the Month". We buy these cute little plants in one gallon or three gallon containers and forget to read the fine print of the plant tag. Small containers do not mean small plants. All plants start out small, even trees. But they all grow and some much bigger than you thought. So the first recommendation is...
Know how big your plants will be at maturity. For most shrubs, maturity is going to be three to five years from planting.
So under the window we will need 4-5 plants that are 3’- 4’ tall and 2’- 4’ wide. The height and width of the plant will be on the plant tag. If the plant grows 3’ tall and 3’ wide, than 12’ divided by 3’ is 4 and that is how many plants we will need for under the window.
The rest of the bed is 12’ long with no windows. You will want plants that will grow taller. Based on all my experience, most shrubs that get tall also get fairly wide. Depending on the plant you select you may need 2 or 3 shrubs.
This is a good start to your design and the foundation plantings will provide a good background for additional landscaping. If you decide to add a second roll of plants, figure out how tall the plants need to be so that they don't grow taller than the plants behind them. This next row of plants under the window should mature at 2' tall. These two shrubs form a stair step landscape - biggest to smallest.
So remember, have a list with the number of plants you need and plant criteria for your new bed. Have specifics when you ask for advice from a salesperson. "I need a plant that is evergreen and will grow no taller than 4'." "My space has full sun and this bed is 12' long." "I want to use a shorter plant in front." The salesperson should be able to show you four or five good plant choices. Using specific information about your area will help eliminate plants that do not fit into your specific criteria.
In order to enjoy your landscape use the proper plants in the proper place and you will reduce the amount of time you spend on maintenance, which means more time to enjoy all the fun things in life.
Before you buy your plants, spend time and read as much information about these plants and you won't have to spend time and money redoing your landscape in the future.
Spend a few minutes getting information and read the plant tags, you will not install the wrong plants in the wrong space and this design crime will be prevented.