Yellow is a contrary color. It’s the bright, life giving color of the sun and in some color the color of deity, but in a yellow room babies cry more and spouses fight more. It’s the color of cheer, but it’s also the color of sickness and decay. Decay is great in the compost pile, it’s not usually the feeling one want to invest the garden with. How do you use yellow in garden design to make best use of its positive traits?
Yellow is the color that is noticed first. It reflects light better than other colors, which means it can over stimulate and fatigue the eyes. But this reflective quality means it’s great for brightening up a shady area. Yellow foliage, found in variegated hostas, coleus, and feverfew ‘Aureum’ seem to almost glow when put under trees. I love it when yellow is used like this; it’s like putting lights or mirrors in! To lighten up the north side of structures, try golden barberry, elder ‘Aurea’ or the yellow leaved ninebark. Beware of putting these plants in shade that is too deep, however- if the light level is too low, the plant will not be able to photosynthesize well enough and will ‘green up’. Even in full sun, putting yellow plants against a dark background- like dark evergreens- really catches the eye.
Just as it glows and looks cheerful in the shade, yellow brings warmth to the garden in those times of the year when the sun’s rays are not at their strongest. In early spring, when the doronicum, forsythia, crocus and daffodils bloom, yellow acts as a stand-in for the returning sun, letting us know we’ve survived another winter. No amount of yellow is too much at this time of year! Likewise, in autumn, yellow comes to the fore again, this time a mature gold rather than the youthful clear yellow of spring. As the sun drops lower on the horizon, the rays strike the gold leaves and the world catches fire for one last glorious color fest before snow and mud cover the garden. We fixate on yellow then, gasping over trees and shrubs we’ve ignored all summer when they were green.
But in summer, I personally find that large amounts of yellow can be too much. Splashes of it are quite welcome, but while an all white garden is sophisticated and an all blue one soothing, an all yellow garden could prove to be migrainous. It’s a color to use with a sparing hand, like a strong spice. Used properly it emphasizes and sharpens other colors rather than overpowering.
Yellow and blue in the garden is a classic combination that I love. Monet thought much of it, and who am I to argue with Monet? Tall 'Blue Jay' delphiniums with buttery 'Sunsprite' roses are a perfect mating. On a smaller scale, try 'Crystal Palace' lobelia with bright yellow pansies. 'Royal Blue' veronica in a soft spill in front of 'Goldsturm' rudbeckia makes a lovely late summer sight. If you haven't any blue plants, try painting a garden bench royal blue and surrounding it with marigolds (tagetes) or calendula of all heights.
Yellow and purple is also a favorite of mine. While golden marguerites tend to annoy me with their floppiness and aggressive behavior, I love the one that's next to the fleabane (erigeron) that has mid-purple petals and a center that's the same yellow as the petals of the marguerite. The two are made for each other. Likewise, a planting of crocus that mixes yellow and purple stands out better than either one alone. And if one wants bright, I find a bed of yellow marigolds (tagetes) with dark purple petunias much more pleasing than those same marigolds paired with red salvia, a blend I see frequently.
In it's palest forms of cream and buff, yellow can be used in the garden in large amounts at any time without fear of overpowering or clashing. 'Moonbeam' coreopsis marries well with other plants much easier than the brighter 'Golden Showers' does. Pale roses like 'J.P. Connell', 'Windrush' or the mini 'Easter Morning' go with any color scheme, even co-habiting peacefully with pink. Daylilies that are sold as white are actually a pale cream. These pale yellows also go with any theme in the garden, from country to formal. Cream is also a good 'blender', softening the effect of two strong colors meeting.
Lemon yellow can be hard to come by. Some types of daylilies (most bred from Hemerocallis flava) are this color- and frequently fragrant- as are a few Asiatic lilies. A few types of marigolds show this slight greenish cast, although most are bright, true yellow to gold. This disappoints me, as I prefer this shade to brassy yellow.
Bright yellow is available in many forms, from 'Baby Sun' coreopsis to tall 'Golden State' zinnias; early primulas to late mums and heleniums. For shrubs, try forsythia for early color; later in the year, try Scotch broom, but make sure it's a sterile hybrid as it is invasive otherwise. Roses offer many bright yellows, from the mini 'Rise 'n Shine' to the floribunda 'Sunsprite' on up to the climbing 'Golden Showers'. There are many yellow iris, including the rebloomer 'Harvest of Memories', which is worth growing even if your growing season is too short for it to rebloom (as mine is most years), as it's a very fine yellow. Aquilegia chrysanthe, the yellow columbine, is tall and fragrant. Thermopsis, trollius 'Golden Queen', oenothera missouriensis & lamarckiana, some lupine, lysimachia punctata (circle flower), rudbeckia 'Goldsturm' and corydalis lutea are all perennial sources of yellow. Calendulas (pot marigold), snapdragons, nasturtium, rudbeckia, sunflowers and, of course, tagetes, all offer quick, brilliant, clear yellow flowers. This yellow looks good in less formal gardens- think how marvelous a field of yellow wildflowers- or even dandelions- looks!
Deep gold or mustard, like lemon, can be scarce. 'Gold Plate' achillea is one source, while chrysanthemums offer many variations on this color. Goldenrod is a good source; a few dahlias turn up in this hue. This yellow can be very hard to place- it works well with rust and orange, but fights with most other colors, especially pink.
Even if one loathed yellow for some reason it would be hard to avoid. Nature is obviously quite fond of it - look how many flowers have yellow centers, and how many leaves turn yellow in fall. But there's no need to avoid it. Used as accent or in abundance, it is beautiful.