By Earl Nickel
Curious Plantsman
Why do we love the color blue? Certainly blue skies above mean sunshine and warming rays on our faces. Blue can also mean the ‘ocean blue’, evoking great mysteries and a sense of tranquility. Pablo Picasso called blue “the color of all colors”.
We gardeners have our own love affair with the color in a way that is both similar and different. The difference is that while blue skies abound, truly blue flowers do not. They are something special in the plant world and nowhere can that be seen in full force than in the pursuit of the “blue rose”. Plant breeders have tried for centuries to achieve this goal. The quest has proven elusive because roses lack the corresponding pigment genes but it’s indicative of the power of this color that horticulturists have pursued such a dream.
Today the power of blue is seen in the myriad ways that those naming new varieties of plants sneak the word “blue” into those names, with little visual evidence to support the claims. Even with those flowers that are “consensus blue” there is an impressive range, from the pale blues of Cynoglossum amabile to the gentian blue of Phacelia viscida. So, in wanting to write about flowers that I consider “true blue” I decided to pick my “signature blue” and circle out from there like ripples in a stream. For me that plant is “Baby Blue Eyes” (Nemophila menziesii). Somehow this CA native annual has captured the very essence of blue, both physically and poetically. What follows is a Spring list of some of my favorite “true blue” flowers.
Annuals
“Baby Blue Eyes” isn’t the only great blue found in California meadows in Spring. Two Phacelias lead the way. The aforementioned P. viscida grows as a 30” tall multi-branching plant and in Spring sprouts dramatic 1″ royal blue flowers. This saturated color is offset wonderfully by a highly decorative nectary. P. campanularia dials back the intensity a bit but still produces rich blue tones. This low growing, scrambling “California Bluebell” adds lovely dark-blushed scalloped foliage to the mix, making it ideal for cascading over a low wall or out of a hanging basket. Both attract bees, butterflies and the occasional hummer.
Want to add a vertical element to a sunny garden plot? Consider the robin’s egg blue tones of “Chinese Forget-Me-Nots” (Cynoglossum amabile) or the gentian blue hues of “Bachelor Buttons” (Centaurea ‘Blue Diadem’). Both are 30-36” tall, multi-branching and produce an endless stream of flowers in late Spring and Summer. If you’ve only grown the small common “Forget-Me-Nots”, this Cynoglossum will be an eye-opener. It yields 100s of little star-shaped flowers, goes to seed. Then the self-seeded plants grow and flower in the same season. Give a bit of space to this charmer as it likes to spread out.
Also called “Blue Cornflower” (owing to them self-sowing in corn fields), this blue Centaurea will self-sow, though not till next season. Papery heads filled with cobalt-blue florets rise on single stalks and wave in the Summer breeze. Deadheading will prolong the show, also making for excellent cut flowers. Drought tolerant for an annual, it combines well with other low water plants. Bees adore both these flowers and hummingbirds love the Cornflowers.
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Speaking of bees, planting the herb “Borage” (Borago officinalis) is a great way to attract an endless parade of these hard-working pollen collectors. They offer the prettiest nodding blue flowers, very similar to those of “Baby Blue Eyes”. Self-sows prolifically, so you normally just need to plant once. Edible leaves can be used like salad greens and the flowers make pretty edible garnishes.
Two gentian blue annuals that get an ‘A’ for effort are Anagallis monellii and Anchusa capensis ‘Blue Angel’. The former, curiously known as “Blue Pimpernell”, forms a low mat of green foliage smothered in 1” royal blue flowers, each with a pink eye and yellow anthers. This native of the Mediterranean is ideal for flower baskets, cascading over a low wall or for lining a walkway. Contrast with the yellow flowers of Coreopsis, orange Ursinia or such CA natives as “Tidytips” and “Meadow Foam”.
Anchusa ‘Blue Angel’ offers masses of half inch cobalt blue flowers in late Spring, on plants that top out at 15” high and wide. Looking like a deeper-hued “Forget-Me-Not”, this annual blooms for 6 weeks then, if you pinch back, may bloom again later in the Summer. With or without the second bloom it is likely to self-sow. Like the Anagallis, it likes sun, rich soil and regular water to bloom its best.
Perennials
There are no shortage of true blue perennials to be found this time of year. Count among those the lovely CA native Penstemon heterophyllus ‘Blue Springs.’ Although it has pinkish tubes, the flowers themselves are a lovely mid-blue. This smaller-sized “Beardstongue” (to 15”) is a prolific bloomer for a sun/part sun location and the 1” tubular flowers are a favorite destination for hummingbirds.
Do you fancy little flags that wave in the breeze? “Blue Flax” (Linum lewisii) looks delicate, its 1″ sky-blue flowers appearing at the tips of wiry 3’ tall stems, but this California native is a tough and resilient plant. A Spring bloomer that likes sun and just a little moisture, it’s the perfect plant to add height without the volume of substantial foliage. With its distinctive radiating lines against an azure blue background, it’s the perfect addition to any dry garden bed.
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Also on the smaller size is a dwarf form of “Blue Marguerite Daisy”, Felicia aethiopica ‘Tight & Tidy’. Topping out at 16” tall and wide rather than the normal 3′, this is one tough ever-blooming evergreen. This charmer is aptly named. Featuring mid-blue petals and contrasting yellow centers, there is no doubt this belongs to the daisy family. Like other daisies, it is drought tolerant and long blooming. Perfect for a low border.
Delphiniums are a great way to add verticality to the garden and there are a host of blues to choose from. D. elatum ‘Sunny Skies’ offers scintillating sky-blue flowers on massive 6’ high stalks! They take the command “reach for the sky pardner” seriously! A repeat bloomer if cut back, this Dowdswell variety is long-lived and built for the long haul. Bees and butterflies love the nectar these long blooming beauties provide.
Four shrubs pack a punch in the true blue department. “Pride of Madeira” (Echium fastuosum) normally has purplish flowers but a sport called ‘Eddie’s Blue’ has vivid cerulean-blue flowers covering the familiar upward-facing flower cones. These 20” long cones smother mature plants, inviting a literal colony of bees over to collect nectar.
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Another popular Echium, E. gentianoides ‘Tajinaste’, offers what can only be described as electric blue flowers. As with all Echiums, the individual flowers are small but plants make up for that in volume. Hailing from the Canary Islands (off the coast of Spain), this modest-sized (to 4’ tall and wide) evergreen shrub throws in vivid red stems and pink stamens to offset that intoxicating shade of blue. Both Echiums are drought and heat tolerant, tough as nails, need virtually no care and in the case of “Eddie’s Blue” will likely self-sow.
I mentioned an Anchusa above but there is a perennial species, A. azurea “Alkanet”, that forms a 4’ multi-branching shrub. Same forget-me-not flowers, only here a deeper and more vivid blue, dark stems and with more of an upright habit. Tough as nails, cutting it back in late Summer may spur a second bloom. Provides a good contrast when planted among roses and fits well into an herb garden.
Lastly, many people are familiar with “California Lilac” (Ceanothus). The flowers on most species are purple but there are a couple of true blue selections. One is the incredibly lovely C. ‘Joyce Coulter’. Cones of lilac-blue flowers smother the 2’ tall shrubs in late Summer and last well into Fall. Spreading out to as much as 8’ wide, although it can be pruned to shape, the fragrant flowers soon attract pollinators of every kind – bees, butterflies and hummingbirds for the nectar and later small birds for the seeds. Very drought tolerant and disease-resistant and ignored by deer. Given its width, it’s a popular choice as a low hedge or to anchor a dry slope, but individual plants are showy enough to be used as a focal point in the garden.
There you have it. True blue. And isn’t it curious that if you look up the phrase in the dictionary, it yields definitions such as loyal and trustworthy. Proving you just can’t go wrong in adding these plants to your garden.
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Blue is elusive! There seems to be more purple than blue, probably because the red color in purple is attractive to some pollinators. Blue is considered to be a color that not many pollinators are impressed with, if they can see it at all. In fact, for many blue flowers, it is just an incidental pigment for flowers that really use ultraviolet or infrared. This might explain why so many plants that should bloom blue bloom white instead. For example, in a group of jacaranda trees, there is likely to be one sickly tree with white flowers. In a group of blue agapanthus, there are likely to be white ones as well. Lupines do it . . . Many blue flowers do it.