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!
Spiknard 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.