Plant Profile: Sun King Japanese Spikenard
I tour a lot of gardens in the summer, and sometimes, you just keep noticing the same plant showing up in one beautiful garden after another. There’s something right about that plant.
This summer, the plant was golden Japanese spikenard or techincally Aralia cordata ‘Sun King’. This bright plant grows best in shady areas where it lights up the plants around it. While Japanese spikenard is a perennial, it has the heft of a small shrub. In ideal conditions with humus-rich soil, adequate water and dappled sun light, it can get 6 feet tall and wide. Truthfully, all the specimens I saw were in the 3 to 4 feet tall and wide range, which is a perfect size for many perennial beds. The chartreuse foliage, which I consider the main benefit of the plant, is brightest in spring and fall.
Some websites list the plant as hardy to USDA Zone 4 (basically, St. Cloud and south in Minnesota) but other sites say it is hardy up to zone 3, which means it is worth a try in northern Minnesota
Sun King looks great with a variety of shade plants in different shades of green and purple: hosta, ferns, purple heucheras. The one photographed above was in the Minnesota State Fair garden of Hennepin Technical College. It was planted near other large, shade loving perennials, sun as Britt Marie Crawford ligularia, and it really stood out in the display — a great choice by the horticulture students at Hennepin Tech!
Spikenard has a white flower in late summer which turns to a blue berry in fall that birds like. One thing to note about this plant is that it spreads via rhizomes, which means there will be suckers you will need to remove. If you like the idea of a shrub-like perennial but want to stay with natives in your yard, consider planting American spikenard (Aralia racemosa), a Minnesota native that has the same heft of Sun King but a more green color.
Mary Lahr Schier is a long-time Minnesota garden writer. Follow her on Instagram at @mynortherngarden_mary.
I discovered this plant while working at Otten Bros this spring and planted one in my yard where is gets a southeast exposure, and it looks great.
Is this a plant that needs to be cut back to the ground every fall or do you just leave it alone?
Ours dies back to ground in late fall. Easy to cut off remaining stems. Ours is sited in shadow of northeast side of house and hemlocks and is growing bigger each of the three years we’ve had it. Will obtain more for other areas of our wooded lot.
I LOVE Aralia Sun King! Its my pride and joy!The neighbors are drooling!!! It seems to me this plant is not your “for the masses” plant. I have not seen this beaut any where in the landscape. Which make me feel special to have this beauty !!!!!
The plant Sun King disappears after the last frost only to return larger in size from the year before. It grows well in the shady back of my garden and offers bright lime green contrast to other plants growing in the shade. It is a real winner
Question: I see that it spreads by rhizome, do you guys find it invasive or tough to control?
My understanding is it is not invasive in Minnesota, though it may be in milder climates. I just planted two in my garden — so I’ll keep an eye on that!
What can you share about transplanting. I have two on the front edge behind a low stone wall but alas, they are blocking every plant behind them. I don’t want to lose them so I would appreciate any advice. I live in Albany NY area. Planted in clay soil hat has been added to for years. Shade all morning.
I assume I should wait until fall or early spring?
You could transplant either in September — giving the plant time to establish roots in its new spot — or next spring, right after it emerges.
I have several in a northern area (muskoka Canada) and my issue is how large they grow….was just attempting to divide the two largest but the underground system is incredibly tough ….looking for any suggestions
They are truly spectacular
Hi Sandra, great question. We recommend reaching out to the Master Gardener Hotline at (612) 301-7590. A Master Gardener will research and return your call, generally within 2-3 days. They sound like incredible plants – want to be sure we give them the best chance to thrive if you divide them.
Is this a plant you can manage the size of by pruning? If so, what is the desirable time to prune?