Delphiniums are renowned for their towering, majestic spires, but this verticality requires thoughtful companions to create a balanced border. Plants with contrasting forms, such as rounded mounds or broad, horizontal layers, provide essential structural support. Ornamental grasses like Fountain Grass (Pennisetum alopecuroides) or Blue Fescue (Festuca glauca) offer a soft, textural contrast at the base of the delphiniums, preventing the border from appearing too rigid. Their flowing habit helps to visually anchor the tall flower spikes, especially after heavy rain or wind. Similarly, the large, bold leaves of hostas serve as a perfect foundational plant, creating a lush, green carpet that makes the delphinium's vibrant blues, purples, and whites truly pop.
The iconic blue delphinium is a star of the garden, and its color can be amplified or elegantly contrasted with the right partners. For a cool, serene palette, pair blue delphiniums with silvery foliage plants like Artemisia 'Powis Castle' or Lamb's Ear (Stachys byzantina). These plants reflect light and enhance the cool tones of the blooms. To create a stunning monochromatic scheme, incorporate other blue-flowering plants such as Catmint (Nepeta), which blooms profusely and helps hide the delphinium's sometimes-ungainly lower stems. For a vibrant, complementary contrast, the warm orange and yellow hues of Daylilies (Hemerocallis) or Yarrow (Achillea) create a dynamic and eye-catching display that is visually exciting.
A practical challenge with delphiniums is their tendency to have a bare lower stem and to die back after their initial summer bloom. Strategic planting with mid-height filler plants solves this issue beautifully. Long-blooming perennials like Salvia 'May Night' or Veronica (Speedwell) provide a continuous wave of color that fills the gap before and after the delphinium's main performance. Their spike-like flowers, though smaller, complement the delphinium's form without competing for attention. For a softer look, airy fillers like Baby's Breath (Gypsophila paniculata) or Lady's Mantle (Alchemilla mollis) create a delicate cloud of tiny flowers or frothy lime-green foliage that gracefully intermingles with the base of the delphiniums, concealing any bareness.
A truly stunning garden border is also a thriving ecosystem. Delphiniums attract bumblebees with their specially adapted flowers. To support a wider range of pollinators and beneficial insects, interplant with species that offer different floral structures. The flat, umbrella-shaped flowers of Yarrow (Achillea) or Sedum 'Autumn Joy' provide perfect landing pads for butterflies and smaller bees. The dense, fragrant flower clusters of English Lavender (Lavandula angustifolia) are irresistible to honeybees and provide a wonderful sensory experience. This diversity not only boosts the garden's health but also ensures a lively and dynamic border throughout the growing season.
