Most groundcover plants cannot tolerate planting under or near black walnut (Juglans nigra), and to some extent English walnut (J. regia), butternut (J. cinerea), shagbark hickory (Carya ovata), and pecan (Carya illinionensis).
The plants below have shown reasonable resistance to the toxin present around those trees.
(Fernleaf Yarrow) Fragrant and finely dissected blue-gray foliage frosted with silver highlights has showy canary-yellow flower clusters June to September.
(Bugleweed) Large deep burgundy scalloped foliage appears black. From late spring into early summer, this plant is covered with showy rich, deep blue blooms on 8-10" spikes.
(Bugleweed) Variegated mint-green, ivory, and burgundy/salmon leaves. 3-6" tall with six-inch indigo blue flower spikes in mid-spring to early-summer. Spreads rapidly.
(Bugleweed) A dense, rapidly spreading ground cover with low rosettes of large, variegated purple-bronze foliage, 5-7" tall. Profuse deep blue-purple flowers on spikes up to 8-10" tall in early ...
(Bugleweed, Valfredda) A rapidly spreading ground cover with compact variegated foliage - dark green splashed with chocolate, with burgundy highlights. Deep blue flowers on 2" spikes, only 2-3" ...
(Pennsylvania Sedge) A native grass that makes an excellent low-growing groundcover with soft long narrow foliage. Thrives in dry soil, can be a semi-evergreen lawn alternative.
(Japanese Shield/Wood Fern, Autumn Fern) Fronds emerge a bold copper-burgundy, turning green with maturity. This dwarf (18-24" tall) fern is excellent for borders and mass plantings.
(Southern/Florida Shield/Wood Fern, Florida Shield Fern) The tall upright growth habit and shiny/leathery dark green fronds makes a striking specimen. The fronds are 30-48" tall and 12" wide.
(Wintercreeper, Radicans, Chinensis) An evergreen trailing vine. Tolerates most environmental conditions, including poor soils and drought. Mature height 12-24".
(Wintercreeper, Radicans, Chinensis) An evergreen trailing vine. Tolerates most environmental conditions, including poor soils and drought. Mature height 12-24".