Unlike the title and refrain from the 1974 pop hit Mellow Yellow by Donovan, YELLOW flowers and foliage in the garden are cheerful, sunny, and uplifting. Yellow can be seductively pale; yummy, bright, and buttery; punchy and fluorescent; in-your-face brassy; or screaming acid yellow.
In color theory, yellow is a primary color, along with red and blue. Green, orange, and purple are colors formed by mixing primary colors. Mixing primary and secondary colors yields tertiary colors or hues given a hyphenated two-word name, such as yellow-green or yellow-orange. There are more shades of yellow than any other color (check out any good paint line) with descriptive names like Canary, Goldfinch, Golden Honey, Sun Kissed, Tuscan Sun to name just a few!
The parade of yellow starts early in our northwest Portland garden with winter- and spring-blooming shrubs. Chimonanthus praecox (wintersweet) starts the show January-February with waxy butter yellow flowers (almost translucent) accented with maroon on the inside. There is nothing quite like the spicy, pungent smell of winterweet on a cold, damp Portland winter day. Next up are the spidery blooms of hybrid witch-hazels. My favorite for yellow color and sweet, subtle aroma is Hamamelis mollis ‘Pallida’ with wavy ever-soft yellow petals brilliantly displayed on bare branches. A close runner-up is Hamamelis x intermedia ‘Arnold Promise’ with its sturdy vase-shaped habit and clear, almost “true” yellow spidery flowers. HPSO member Lucy Hardiman has a champion specimen in her southeast Portland garden.
Overlapping and taking the lead from witch-hazels in bloom sequence are two other favored yellow-flowering shrubs – Edgeworthia chrysantha (Chinese paperbush) and Corylopsis spicata ‘Aurea’ (golden spike winterhazel). Edgeworthia produces deliciously scented umbels of yellow tubular flowers on thick, naked branches. Golden Corylopsis provides a double-whammy of dangling pale yellow flowers followed by acid yellow leaves that shift bright gold to chartreuse late in the season.
Another remarkable yellow-blooming shrub is Stachyurus salicifolius (willowleaf spiketail). It’s a lovely graceful, arching evergreen shrub from China with long willowy evergreen leaves. In early spring chains of creamy yellow bell-shaped flowers are guaranteed to start a conversation.
It’s not all about colorful blooms, however. Flowers are fleeting and foliage rides much longer during the gardening season. An excellent example is Ribes sanguineum ‘Brocklebankii’, a golden yellow-leafed form or our native flowering currant. It has typical trusses of dark pink flowers in early spring accented against the warm foliage. Too much sun can burn the leaves so a lightly shaded spot or morning sun is best. Another currant that I am crazy about is Ribes odoratum (clove currant) and the cultivar ‘Crandall’. Both sport golden yellow trumpet-shaped flowers in racemes in spring and emit a strong, spicy, clove-like fragrance. The punchy flower color and fragrance is to die for!
Down lower to the ground, there are many perennial plants that I wouldn’t be without for their yellow springtime color. Euphorbias of all kinds lead the list, in particular architectural Euphorbia rigida with its stiff upright stems clothed in long, pointed, powder-blue leaves topped by fluourescent yellow-green flower heads. Another favorite is Euphorbia polychroma ‘Bonfire’, an herbaceous cushion spurge whose new foliage emerges deep red-purple shifting to burgundy in mid summer. The low-mounded foliage to 1.5 foot tall is covered by fluorescent yellow to chartreuse bracts. For softer yellow perennial flower color, Scabiosa ochreleuca (pincushion flower) is a bringer of bees and butterflies, practically everblooming, and drought and deer resistant. Hundreds of 1.5” soft primrose blooms cover the multi-branching, 3-foot-tall stems.
I liberally use ornamental grasses and sedges in my naturalistic garden designs to knit together and integrate plantings. One of my favorite workhorses for full sun is Molinia caerulea ‘Variegata’ (variegated purple moor grass) This tufted, compact perennial has dense clumps of slender, foot-long green leaves marked with stripes of creamy yellow. In summer, slim, pale yellow flower stalks rise up 3 feet tall in a vertical pattern that glows when backlit by the sun. Molinia combines well on one of our hillside gardenslopes with the complementary cornflower blue blooms of Catananche caerulea. In the shade, I am fond of Carex oshimensis Everillo (EverColor R), a Japanese sedge with fantastic bright lime-green foliage that ages to golden yellow during the season. I wouldn’t be without Japanese Hakonechloa macra ‘Aureola’ and ‘All Gold’. Likewise, Luzula sylvatica ‘Aurea’ (great woodrush) with bright golden foliage in late winter and early spring fading to lime-green by midsummer.
For a big bold, ever-present yellow statement in my gardens, I always find room for a specimen or clusters of Yucca filamentosa ‘Color Guard’, my favorite golden yellow-centered variegated yucca, and Symphytum x uplandicum ‘Axminster Gold’ (yellow variegated comfrey) with large, coarse grayish green leaves artfully edged in vibrant lemon-yellow.
Yellow is a happy color that brightens and lifts gardens and souls during the spring renaissance in our gardens.
