1. Herbicide Forum December 2015
New Weeds and Controls
Herbicide Forum
December 2015

2. Aegopodium podagraria Bishop’s goutweed
Basal leaves, triternate
Spreads by rhizomes
Seed dispersal unimportant
Invades woodlands, forest edges, open areas
Prefers partial shade
Widely sold as a ground cover

3. Aegopodium podagraria Bishop’s goutweed

4. Aegopodium podagraria Bishop’s goutweed
“where it hath once taken roote it will hardly be gotten out againe, spoiling and getting every yeere more ground, to the annoying of better herbes” (Gerard, late 1500s)
“with his roots stamped and laid upon members that are troubled or vexed with gout, swageth the paine, and taketh away the swelling and inflammation thereof, which occasioned the Germans to give it the name of Podagraria, because of his virtues in curing the gout.” (Gerard)

5. Aegopodium podagraria Bishop’s goutweed
Manual control: hand pulling, raking, digging; remove all rhizomes and roots
Solarize: cover in spring
Chemical:
Glyphosate in spring or summer?
Older leaves “resistant”?
Multiple treatments necessary?
Non-variegated form may be more difficult to control

6. Barbarea vulgaris Yellow rocket
Biennial (basal rosette 1st year)
Basal leaves large terminal lobe
Stem leaves without stalks, may have auricles
Winter growth
Seed dispersal
Likes sun, open areas

7. Barbarea vulgaris Yellow rocket

8. Barbarea vulgaris Yellow rocket
St. Barbara’s herb (all members of the genus are Herba sanctae Barbarae)
Vitamin C and other nutrients
Widely cultivated
The absence of fresh food during the winter made scurvy prevalent; in the spring, people eagerly sought "scurvy grass" to eat.
"Our Legal Heritage, 5th Ed." by S. A. Reilly

9. Barbarea vulgaris Yellow rocket
Rapid establishment but poor competition?
Seed longevity 10+ years?
Manual: hand pull
Mechanical:
mow to prevent seed set
Cultivate at rosette stage
Chemical: spray rosettes (fall, winter, spring)

10. Carex pendula Drooping sedge
Triangular stem
Exceptionally long inflorescences (to 6 in.)
Large plant (3+ feet)

11. Carex pendula Drooping sedge
CARPEN
Riparian, wetland, other moist areas
Seeds June-July
Also spreads by rhizomes
Contaminant in bird seed?
SCIMIC

12. Carex pendula Drooping sedge
Even the ferociously elegant sedge, Carex pendula, is a brute. It scatters seed everywhere... Lovely, yes, but I broke two spades trying to uproot one big clump. Destroy every seedling or buy spades by the dozen.
David Stuart, The Guardian.com

13. Carex pendula Drooping sedge
Control methods??
“I'm going to have a bonfire on top of it.”

14. Linaria vulgaris Yellow toadflax
Perennial, rhizomatous
Typically 1 ft. tall
Snapdragon-like yellow flowers are spurred
Narrow leaves
Hybridizes with Dalmatian toadflax

15. Linaria vulgaris Yellow toadflax

16. Dalmatian Yellow

17. Linaria vulgaris Yellow toadflax
Manual: hand-pull small seedlings
Mechanical: not recommended (mowing and grazing help it spread)
Biocontrol: weevil, effectiveness unknown
Chemical: several options
Dicamba, 2,4-D, imazapic
Glyphosate (1.5 to 2 percent in early spring)
Imazapyr (relatively high rate)
Surfactant necessary, waxy leaves

18. Chelidonium majus Greater celandine
Biennial
To 30 in. tall
Sap
Deeply lobed leaves with long petioles

19. Chelidonium majus Greater celandine