Before you select specific plant varieties for your garden, draw your garden beds onto paper to scale. Then for each plant, draw a circle to represent its spread at maturity. For example, if you’re choosing a shrub that will be a meter wide once it’s established, draw a one-meter circle. The same applies to perennials, groundcover and even small trees.
Once you’ve drawn the circles, it should be apparent if any plants are overlapping one another. Adjust the number of plants or perhaps the width of a group accordingly on your graph paper. It is so much easier to make those adjustments on paper before you plant rather than trying to correct mistakes afterwards.
One of the biggest and most common mistakes when planning a garden is to judge the amount of space needed based on the size of the plants when they’re first placed in the garden. The result is that new garden bed may look disappointingly empty because there is too much open ground between the small shrubs and perennials.
To fill all that open space, too many plants may be added to compensate and now the bed looks lush and full on planting day which feels so rewarding. But all of those plants have been bunched together and are competing for space so the garden lacks good structure and it will soon become a undifferentiated mush.
It’s better if the garden is balanced and looks a little reserved on the day it’s planted because it will soon grow into a lush planting. If each plant has adequate space to grow into its mature form, the layers will be clear and the structure defined.
Other common spacing mistakes:
- Plants that have been spaced too close together will eventually become overgrown which can be a problem especially if they are planted near walls, seating areas, paths, entrances or lawns.
- You will need to keep in mind the canopies of trees and where they will eventually spread as they mature because they will change the sun conditions underneath them.
- Overcrowded plants may also make it difficult to walk through certain areas and perform maintenance.
Plan your plant spacing carefully before you start planting. Make sure you have thought about how far plants will spread at maturity but also consider the relationship between the plants, the edges of the garden and the hard landscape areas.
The spacing of plants is relative to the plant forms and is not necessarily determined by distance between stems. It’s best to think of groups or masses of the same plants. The repetition of similar forms will create a visual rhythm in your garden. On the other hand, unique or specimen plants need a certain amount of open space around them for dramatic effect.