By Barbara Goodman, EMGV
Bittercress (Cardamine hirsuta), also known as lamb’s cress, spring cress, wood cress, or flickweed is a member of the mustard family Brassicaceae. It is a winter annual, but can persist year-round in a moist, shaded environment in disturbed areas.
I find it throughout my garden primarily in and along the gravel paths (where I might have tracked it’s seed over the years), and in the moist corners of some garden beds. It also loves my currently dormant raised veggie bed. Since I must garden in high shade conditions on our wooded lot, I have the perfect environment for it. It also loves container pots, so be sure to pull every last little seedling out of plants that you bring home from the nursery.
This pesky menace is native to Europe and western Asia but was introduced and naturalized throughout much of the US and the world. *

As it grows, it demonstrates an upright growth habit with a dense basal rosette. The shoots bearing its tiny white flowers grow up from the center from 3 to 8 inches high. Pull these little devils up by the roots before the seedpods form. When mature, the pod splits open and forcibly expels the sticky seeds up to 6 feet! One plant can produce 5,000 seeds that can germinate quickly or remain viable in the soil for many years. Hence the clusters that occur. In the gravel paths a scuffle hoe can cut them down, but it is best to pull by hand and get the root. I prefer to garden chemical-free, but I may have to seriously consider a pre-emergent weed treatment in the future.
References:
*From ENH1250, one of a series of Environmental Horticulture Department, UF/IFAS Extension. Original publication date December 2014. http://edis.ifas.ufl.edu/ep511.