Weed of the Month

Learn about noxious weeds and steps you can take to manage or eradicate.  Each month we will bring you a new profile and helpful resources.

March Weed Profile

Dames Rocket

Hesperis Matronalis

Dames Rocket is a List B biennial species and belongs to the mustard family (Brassicaceae).

It is an escaped ornamental that can be found in rangelands, pastures, gardens, forests, ditches, and rights-of-way. It can be found in many wildflower seed mixes. It is a prolific seeder and escapes ornamentation quickly. It may be mistaken for some species of phlox. Phlox have five petals, compared to the four that Dames Rocket sports. Dames Rocket was introduced around the same time as European settlement.

Plants grow up to a height of four feet tall and have white or purple, four-petaled flowers. Flowers are clustered on terminal stalks. Seed pods are narrow and up to 1½ inches long, as with all mustard species, these pods are called siliques. Leaves are alternate, lanceolate (lancelike), 2-4 inches long, and have toothed margins.

Dames Rocket can spread quickly and displaces many of our native plant species.


Wisconsin Department of Natural Resources

Noxious Weeds of Colorado 14th Addition
Colorado Weed Management Association



Jamie Jones
Alicia Doran
Jeffco Invasive Species Management

Items of Interest

Weed of the Month


January Weed Profile – Common Mullein

February Weed Profile – Cypress Spurge

March Weed Profile – Dames Rocket


January Weed Profile – Knotweed

February Weed Profile – Rush Skeletonweed

March Weed Profile – Black Henbane

April Weed Profile – Chinese clematis

May Weed Profile – Houndstongue

June Weed Profile – Milk Thistle

July Weed Profile – Oxeye Daisy

August Weed Profile – Spotted Knapweed

September Weed Profile – Perennial Pepperweed

October Weed Profile – Yellow Flag Iris

November Weed Profile – Common St. Johns Wart

December Weed Profile – Field Bindweed


January Weed Profile – Dalmatian Toadflax

February Weed Profile – Common Mulllein

March Weed Profile – Mediterranean Sage

April Weed Profile – Saltcedar

May Weed Profile – Absinth Wormwood 

June Weed Profile – Eurasian watermilfoil 

July Weed Profile – Yellow starthistle 

August Weed Profile – Hairy willowherb

September Weed Profile – Yellow toadflax

October Weed Profile – Chamomile

November Weed Profile – Diffuse knapweed

December Weed Profile – Poison hemlock


January Weed Profile – Cheatgrass

February Weed Profile – Myrtle Spurge

March Weed Profile – Hoary Cress

April Weed Profile – Leafy Spurge

May Weed Profile – Scotch Thistle

June Weed Profile – Dyer’s Woad

July Weed Profile – Orange Hawkweed

August Weed Profile – Purple Loosestrife

September Weed Profile – Teasel

October Weed Profile – Canada Thistle

November Weed Profile – Russian Knapweed

December Weed Profile – Russian Olive