Invasive: Hairy bittercress (Cardamine hirsuta) Video field exploration This month’s weed is less of a threat to natural areas than many featured weeds–though it does show up there–but is one that is very common in urban yards, to the great chagrin of gardeners. Hairy bittercress is a short (usually < 15 cm, or 6″) annual […]

COVID-19 poses no threat to plants, but our leafy friends are no strangers to pandemics of their own: chestnut blight, Dutch elm disease, sudden oak death, and other pathogens have each done tremendous damage to forests in America. Right now, the Pacific northwest is bracing itself for the inevitable arrival of a huge threat to […]

Invasive:  Scotch broom (Cytisus scoparius) Characteristics:  Scotch broom is a perennial member of the pea family (Fabaceae).  It is a deciduous shrub, 1-3 m (3 to 10 ft) tall, though its many slender, erect, angled branches remain dark green year-round. Its small (5-15 mm) leaves have three leaflets. Abundant small, yellow, pea-shaped flowers appear from […]

Weed of the Month:  Herb-Robert (Geranium robertianum) Characteristics: Herb-Robert—also called Robert’s geranium, or, colloquially, “stinky Bob”—is both a winter and spring annual with light-green, deeply dissected leaves. In late fall the foliage turns red. The stems fork and are brittle at the joints. They are pubescent (hairy), reddish (especially under high light conditions) are can […]