Perennial gardens have a long tradition in landscape designs going back to some of the earliest gardens of Asia. However, they are most associated as beginning with the renaissance gardens of Europe. During that period, international travel expanded as did interest in horticultural specimens from across the world. The English perennial garden of the late renaissance and modern era are held as the prime example of design and excellence. These gardens were often extensive displays of color and variety requiring a staff of gardeners to maintain. Today’s homeowner can learn from those gardens and incorporate the concepts at a scale appropriate to their property and the amount of time they can invest in upkeep.
A classical perennial garden can vary in dimensions and is designed in at least three layers. That requires at least 10’ of depth minimum, though 15’ or more is needed to really pull off that classical landscape design of the perennial garden. The length of such garden designs is at least 10’ and can be as long as 100’ or more. The design depends of the scale of the space and the outdoor living environmental that will contain the perennial garden. The three layer minimum layers are a tall backdrop, a medium care and a lower growing foreground. Four, five or six layer gardens follow the same principles.
The key to a beautiful perennial garden is understanding color theory, plant texture combinations and plant bloom periods. I will address color theory in landscape design during a future blog as it is a topic of its own. The relationship between the varied plant textures creates an important aesthetic result in the landscape design. Use perennials with distinctly unique textures adjacent to one another in order to help delineate the garden and the design. Textures can be as important as colors in a successful perennial garden. The goal with bloom periods is to create a garden that has color and interest throughout the season. Don’t forget to consider the fall leave change color of a perennial in this part of the design.
Annual flowers might be considered cheating by some landscape designers, but they are a great way to ensure a beautiful garden throughout the season. Annual flowers have long, dependable bloom cycles and are great for tucking into bare spots. Some annual flowers have displays that are simply unachievable with a perennial. Delphinium for example create a powerful color display early in the season while other perennials are just getting started (Delphinium are technically a bi-annual but are best used as an annual in the gardens of the north east).
When laying out the perennial design, create a repeating pattern throughout the garden. This creates a pleasant and somewhat logical aesthetic. It is a more relaxing experience for the viewer. Avoid perennials that are self-seeding or you will fight their spread throughout the garden and that will ruin the intent of the design. Double dig your planting beds incorporating as much rich compost as possible. Mulch with a very light, highly ground and composted peat based dressing. Do not use a standard mulch in a perennial garden since you will be working, turning, and maintaining it often. A regular triple ground hardwood mulch will just get in the way if your are a true perennial garden creator. A perennial garden is dynamic and ever evolving as the designer or gardener learn and adapt.