Spheres and circles: A Cephalnthus occidentalis; B, D Hypericum prolificum; C onion flower head; E Papaver somniferum pod; F Helenium flexuosum cv.; G Anethum graveolens; H Dalia ‘Stoneleigh Cherry’; I Helenium autumnale cv.; J Allium ampeloprasum; K Gomphrena globosa; L Tagetes hybrid; M Ageratum houstoinianum ‘Album’; N Allium sphaerocephalon; O Echinops ritro.
I asked the fashion designer turned gardening maven and author, Dianne Benson, aka Dianne B., what she’s been interested in lately. “My new penchant for circular leaves has led to all sorts of surprise combinations: Ligularia ‘Othello’, and L. ‘Britt-Marie Crawford’ are just right to surround large-leaf trillium,” she shared. “The demure flower spike of Darmera peltata surprises me in early spring, and then makes way for round crinkle-edged leaves.” The ground beneath these plants is covered with shiny round European ginger. The black stems of maidenhair fern (Adiantum pedatum) are topped by “circlet upon circlet” of tiny leaflets that give the scene an ethereal quality.
Conventional design advice promotes activity and contrast. For every disk and orb, there should be a spike and spire. But there is soothing effect in Dianne B.’s planting, as the eye flows from one “puddle of floating pads to the next, from plants like Astilboides tabularis (like a table) leaves.”
Placing rounded forms together may produce a soothing, comforting result. Massing globular flowers adds weight and volume. A mound of flat-flowered chrysanthemum daisies could make a similar anchoring contribution. Numerous pompom blossoms together go a step further: They promote visual harmony.
The most symbolically soothing plants might come from the globular seedpods of Papaver somniferum, the opium poppy, for obvious reasons. Spherical flowers could also solicit a contrary response. A close inspection of the flower or seed heads of tall Allium varieties look like fireworks displays. The effect, if not as raucous as actual pyrotechnics, is certainly energizing.
Rather than moving the planting along or stopping it in its tracks, the allium balls hover and encourage us to linger, as well. More dynamic are the pincushion flowers of the scabiosa varieties, or their tall cousin Cephalaria gigantea. There are also the prickly flower heads of globe thistle (Echinops ritro), which remain standing after its tiny blossoms have dried and blown away.
An interesting study in contrast might be to create formal square beds edged by dwarf boxwood, and then fill those with floppy, uncontrolled broad round leaves, or lollipop-like spherical flowers. Architectural elements are softened by the amorphous shapes—a nice fusion of class and sex appeal.
An orange deciduous Knap Hill azalea blooms in front of a fastigiated red beech Fagus sylvatica ‘Dawyck Purple’, and behind the variegated willow Salix integra ‘Hakuro Nishiki’.