Yellowroot

Size, growth and what to expect

Yellowroot grows at a medium pace, 6 inches to a foot a year in our growth estimator. Its upright, mostly unbranched stems stand 1 to 3 feet tall, each topped by a cluster of leaves, and it spreads into a patch 6 to 10 feet wide. An Arnold Arboretum planting from 1887 seed still flowered in 2018.

Drooping sprays of small, star-shaped, purple-brown flowers open in April and May. The leaves, divided like celery into three to five toothed leaflets, turn yellow, bronze and reddish purple in fall. Star-shaped clusters of small pods follow, green at first and drying to yellowish brown. Gamebirds, songbirds and small mammals use it for cover and food.

It grows wild from Pennsylvania and West Virginia south to northern Florida and west to Kentucky, Tennessee and Mississippi, with a few stands in western Louisiana and southeastern Texas. Its home is shaded stream banks, moist woods, thickets and rocky ledges. It has escaped from gardens farther north, in New England, New York, New Jersey, Maryland and Ohio.

How to grow Yellowroot

Yellowroot grows in part shade or full shade, in a moist, acid soil, sandy or loamy and rich in leaf litter. It takes wet ground, and some drought once it is settled. Alkaline soil yellows its leaves, and the best fall color comes with some sun. Set plants 3 feet apart and keep them 3 feet from a wall. At its size it can go within 15 feet of overhead wires.

Saplings ship bare-root or potted. Plant them dormant, from leaf fall until bud swell, in a hole wider than the roots and no deeper. Set the crown at the soil line, put the native soil back in, and keep the mulch clear of the stems. Sow the seed in early winter and keep the covered flats in an unheated greenhouse for about three months. Seedlings come up 10 to 20 days after the flats are uncovered in early spring. Dividing an older clump is the surest way to make more plants.

Water it every day for the first two weeks after planting, then every two to three days until week 12. After that, water weekly through the first two summers if rain is short. Deer tend to leave it alone. A walk or a metal edging holds back its spread where it is not wanted, and a heavy coat of ice can break its brittle stems.

Each flower carries both male and female parts, so there are no male and female plants to pair. It has no major pest or disease problems. In good conditions it can spread without limit by its underground stems.