Aralia cordata ‘Sun King’. Photo: terranovanurseries.com
It’s big, it’s bold and it’s golden … and it’s now the 2020 Perennial of the Year, as chosen by the Perennial Plant Association: Aralia cordata ‘Sun King’, the golden aralia. It was nominated again and again for several years and has finally made its way to the top.
I first saw this plant in 2011 and immediately lusted for it, but it wasn’t yet available locally. Then, in 2012, this golden variety of the Japanese spikenard (A. cordata) won an International Hardy Plant Union Outstanding Plant Award, making it all the more desirable, as they don’t give out awards like that to wimpy plants. It was originally found and introduced by the guru of Asian plants, Barry Yinger, apparently in a garden center on top of a Japanese department store.
When I finally got a hold of a specimen of golden aralia in 2014, I already knew enough to ignore the dimensions given on the label. It claimed it would be 3 feet (90 cm) high and wide. Yeah, right! That’s how big it gets the first year! By year 4 or 5, your plant will likely be 5 or 6 feet (1.5 m to 2 m) tall and nearly as wide. In my cool summer climate, which it seems to love, it grows to nearly 9 feet (2.75 m) tall and 7 feet (2 m) wide, at least if you grow it in partial shade and rich, evenly moist soil.
Although it looks like a big shrub, it’s a true perennial, dying to the ground in the fall and starting over in the spring.
But it’s a stunning plant! The huge leaves with reddish stalks are compound and double to triple pinnate, with each heart-shaped (that’s what cordata means) leaflet looking like an individual leaf. The leaflet is lightly toothed … and a striking chartreuse early in the season, fading to a still lovely bright lime green by summer’s end. (In too much shade, it will revert to medium green.)
The plant blooms readily enough in late summer with tall panicles of round umbels at the top of the plant. The individual flowers are white, but backed by a light-green ovary, so appear more lime green than white. Given the brilliant yellow foliage just below, the flowers have fairly little impact, although clearly bees love them.
They give way in late fall to tiny nearly black berries that birds love and that are visually much more interesting than the flowers. The berries aren’t poisonous, but nor are they considered edible either.
The young stalks are edible though and this plant has been called mountain asparagus for that reason. Called udo in Japanese, the stalks are eaten blanched or pickled as a vegetable in its native lands: Japan, Korea and China. However, I don’t think most gardeners will be eating their golden aralia any time soon: it’s far too attractive for that!
Growing Your Own Golden Aralia
This plant is considered a tough, no-nonsense perennial, yet, to my great chagrin, I must confess that I failed twice with it. I really wanted it in a deeply shady spot of my yard where it’s golden foliage would have created the effect of a beacon, but clearly the label’s claim that it is adapted to shade is open to interpretation. Both times, the plant hung on through the summer and never came back in the spring. When I tried light shade, it did much better. In fact, it grew to enormous dimensions.
I keep reading that it’s not adapted to sun, but that’s probably in hotter, drier climates than mine. I see it in full sun here and it does just fine. My guess is it will grow perfectly in deep shade in the South, where the sun is more intense and penetrates more deeply, but will need some sun in the North where sunlight is weaker. And likewise, it will thrive in full sun in the cooler North, but need some shade in the sweltering South.
Sun King aralia seems to like rich, evenly moist soil, either acid, neutral or slightly alkaline, but will tolerate drought, sulkily, if necessary. If you don’t keep it watered, though, it will flop and there is nothing more annoying than a 9-foot (2.75 m) plant lying collapsed across your walkway. It will need deep soil, given its massive root system.
It’s claimed to be hardy in USDA hardiness zones 3 to 9 (AgCan hardiness zones 4 to 9) and I can verify that it does fine in the coldest part of that range. I’ve seen it used beautifully in pots, where it remains of a more modest size (about 3 feet/90 cm tall and wide). Pot-grown plants will need protection in cold winter areas.
Do be aware that the golden aralia is a bit slow to awaken in the spring, so don’t give up hope. And that’s probably just as well, as I’ve heard it can be damaged by late frosts. In my climate, there is no sign of life until June, yet a month later, it’s taller than me.
Deer are said to despise Japanese spikenard and I’d assume other plant nibblers, like rabbits and groundhogs, would feel the same. I hear that slugs can go for early growth, but it soon outgrows them. I’ve seen no slug damage on my plant, though, but then, I don’t have much of a slug problem. Sun King aralia doesn’t seem to have many other insect enemies or serious diseases.
Oh, and considering that its woody relatives like devil’s walking stick (Aralia spinosa) and angelica tree (Aralia elata) are insanely spiny and sucker like crazy, it’s nice to know that the Sun King is totally spineless and doesn’t seem to sucker at all. Nor does it self-sow to any great degree. Do note, though, that any seed-sown plants will be all green. If you want to multiply it, try division or stem cuttings.
You may already be growing this great plant—so many people are!—but if not, it’s an outstanding big perennial most gardeners could easily find good use for.