University of Illinois Extension
Formal or Informal - Garden Style and Display - Stepping Stones to Perennial Garden Design - University of Illinois Extension

Formal or Informal

Gardens fall under two categories when it comes to style - formal or informal. Before putting your design on paper you need to determine your style. Formal gardens follow straight, geometric lines to determine the shape of the beds. The geometric shape selected may be copied from an architectural feature found on your home. Formal gardens rely on symmetry. One garden will match another. In a small space, the symmetry becomes the focal point. That is what the eye registers. It recognizes the pattern and takes everything in as a whole. Formal gardens date back many centuries. Palatial castles often had formal gardens. If contemplating this style do keep in mind the best way to view a formal garden is from an elevated point. Centuries old formal gardens all have verandas or balconies for viewing. Looking down you are able to appreciate the symmetry and balance. Formal style is high maintenance.

Informal gardens are more popular. They follow the natural terrain by using curved lines. The human eye follows curves easier than straight lines. In fact, curves are more natural. There are no perfectly straight lines of great length in nature. The only illusion of a straight line is the horizon. All perfectly straight lines are man made. Balance is created not through symmetry (as in a formal garden) but with plant material characteristics such as plant shape, color, size, and texture.

What is balance? It is visual weight. A yard bordered by a large, established windbreak on one side and nothing on the other is not balanced. The visual interest is heavily weighted towards the massive plant material. A garden with bold colors on one side and milder hues on the other creates visual imbalance. The eye takes in the garden but not as a whole - the bold colors dominate. Balance can be achieved in many ways. Most often it is achieved with plant size and plant color, but texture also can support the balance of a garden.

What is texture? It is visual feel. A large yucca is a visual 'ouch.' Sharp points and strong lines classify it as coarse textured. Coarseness also comes from leaf size. Larger foliage stands out. Other coarse textured perennials are Rodgersia pinnata and Echinops ritro. A 'Silver Mound' Artemisia is visually soft. It looks like an old familiar pair of flannel pajamas. We would classify it as fine textured. Other fine textured perennials are Coreopsis verticillata, Thalictrum rochebrunianum and Adiantum pedatum. Their foliage appears lightweight. Careful placement of textural plants contributes to a garden's balance. Variegated foliage appears coarser than their solid-colored counterparts. Highly reflective, glossy foliage increases visual feel. Rarely do plant references describe texture. Illustrated references can help. This is frustrating, so ask questions when visiting your favorite nursery or garden center.

Flower form contributes to overall garden balance. Actually, what most people call a flower is really an inflorescence made up of many individual flowers or florets. Planning for a variety of flower shapes offers visual interest as well as contributes to the overall balance of the garden. The common shapes are:

Flower Type


Daisy or Head

Purple Coneflower, Echinacea purpurea

Flat Topped or Corymb

Yarrow, Achillea sp.

Spike or Raceme

Delphinium, Delphinum sp.

Rounded or Umbel

Giant Flowering Onion, Allium giganteum

Branched or Panicle

Switch Grass, Panicum virigatum

Plants are available in many sizes and shapes. Basic forms are vertical or columnar, such as Delphinium; mounded such as a fall-blooming mum (Dendranthema sp., formerly Chrysanthemum sp.); and horizontal or prostrate such as creeping phlox (Phlox subulata). Most perennials fall under these three forms. Be sure to include a variety to maintain visual interest.

Another term you often hear is harmony. This is achieved through color compatibility, blending colors in a pleasing manner.