My notion of the perfect flower garden was formed early in life. I took it directly from a fanciful illustration of an English cottage garden in my nursery-rhyme book. I recall being enchanted by the towering spires of blue blooms—probably delphiniums, but possibly ladybells—before which Mistress Mary flounced contrarily down her garden path.
In reality, stately plants bearing slender inflorescences of blue do lend grace, romance, and repose to a garden and provide counterpoint to frothy phloxes, puffy alliums, dotty daisies, and misty grasses. I’ve found I can grow a season-long succession of spiky blue flowers, most of which return year after year.
First come the camassias, from late March into May. Most effective in mass, our eastern native wild hyacinth (Camassia scilloides; USDA Zones 3–9) slowly unfurls a tapering raceme of pale blue starlike flowers atop a sturdy two- to three-foot stem. Camassias grow from bulbs and do well in sun or light shade in consistently moist soil that drains but not quickly. They vanish into dormancy as soon as seed is set. Selections of the western North American species C. leichtlinii subsp. suksdorfii (Zones 4–8)offer blooms of a deep violet blue that contrasts smartly with their own vivid yellow anthers.
We may think of Spanish bluebells (Hyacinthoides hispanica; Zones 3–8) as short and squat, but the periwinkle blue–flowered ‘Excelsior’ can grow to 20 inches or more, with a stiffly regal bearing. The exquisitely shaped bells cling to a scape that emerges from a clump of fleshy straplike leaves, which wither shortly after the March and April bloom. The bulbs remain busy underground, increasing with rabbitlike fecundity to produce a showier spectacle every year. Spanish bluebell thrives in sun or shade and in almost any soil.
Blue false indigo (Baptisia australis; Zones 3–9) blooms for a couple of weeks from late April into May, with lupinlike spires of blue pea flowers. After blooming, the shrub makes an attractive silver-blue background for summer- and fall-flowering annuals and perennials. The drought-resistant, sun-loving long-lived false indigo is easy to grow in most well-drained soils.
Now, the fancy hybrid delphiniums are as rare as icebergs in my sultry Alabama climate. If the heat doesn’t get ’em, the slugs will. But I’d love to see breeders do more with our eastern and central United States native species, such as the willowy Delphinium exaltatum (Zones 5–7), which displays six-foot racemes of long-spurred, gentian blue flowers; the similarly statuesque D. carolinianum (Zones 5–8); and the delightfully unfussy two-foot D. tricorne (Zones 4–8), a colorful habitué of woodlands and prairies.
The delphinium’s hardy annual cousin larkspur (Consolida spp.) is more common in gardens here, coming into bloom the latter part of April and carrying on for eight weeks or more. For sheer blueness I adore the four- to five-foot C. ajacis ‘Sublime Azure Blue’, a double-flowered strain with spires of a chilly soft blue. Some gardeners brag that larkspur self-sows to peskiness in their gardens, but for me it dwindles over time unless I’m careful to save and sow the seed (in fall for bloom the next spring).
It’s a pity our many native skullcaps (Scutellaria spp.) are strangers to most gardens. In May and June, pointy upright panicles of luminous lavender blue blossoms appear among the scalloped fuzzy leaves of heartleaf skullcap (S. ovata; Zones 4–8), a charming rhizomatous woodland mint.
I recently discovered on the Internet that there are numerous spectacular ladybells (Adenophora sp