This is the first design principle I talk about when I'm giving people advice about designing their own ornamental gardens. For low maintenance purposes, I mostly recommend perennials over annuals, but the thing people need to be aware of is that most perennials flower for a much shorter period than annuals, which generally flower all summer long. So to make your garden look interesting even when some things are not in flower, it's important to consider the plant's form i.e. its shape or outline.
Round, mounding plants:
cushion spurge, artemesia 'Silver Mound', perennial geraniums
Some ornamental grasses, daylilies
snakeroot, spiked veronica, obedient plant, delphiniums, verbascum
astilbes, hostas, columbine, meadow rue, bleeding hearts
...and some plants are combinations of these shapes depending on whether or not they are flowering.
Here are some examples of forms that work well together in my garden:
- mounding geraniums in front of upright siberian irises or fanning peonies
- arching daylilies next to upright spiked veronica (these also bloom at the same time)
- tall, upright to arching grasses behind fanning astilbe (warning: astilbe is a moisture-lover!)
- upright mulleins with the billowing roundness of bearded irises
- spiky perennial salvia next to fanning, flat-topped yarrow
- broad fans of bergenia leaves in front of arching daylilies or ornamental grasses
- fanning hostas in front of upright snakeroot
You'll notice there are also contrasting textures in a lot of these plant combinations. Although foliage colour also makes things interesting, it is secondary to texture. A great way to check for a good plant combination is to look at the picture in black and white and see if it still looks interesting:
For more great perennial plant combinations, check out the post I wrote about Piet Oudolf-inspired plants for Calgary sustainable gardens, which was published in the Calgary Horticultural Society's magazine last year.
If you would like an urban paradise that rejoices the eye and refreshes the spirit, view My Services for consultation details.