Michigan law regulates the sale of certain noxious weeds. Noxious weeds are divided into two categories. Prohibited species cannot be sold or grown in the state. Restricted species are those that may occur within the state and are generally considered as nuisances or economically detrimental.

The various Acts and Regulations that pertain to weeds are summarized below:

• Regulation 623 - Field Seed Certification - Includes standards for field crop seeds and tolerances for contaminants
• Act 329 of 1965 - Michigan Seed Law - includes limit on percentage of weed seed
• Regulation 715 - Seed Law Implementation - list prohibited and restricted noxious weeds

Prohibited Noxious Weeds

1. field bindweed, Convolvulus arvensis
2. hedge bindweed, Convolvulus sepium
3. Canada thistle, Cirsium arvense
4. morning glory, Ipomea species
5. puncturevine, Tribulus terrestris
6. plumeless thistle, Carduus acanthoides
7. musk thistle, Carduus nutans
8. bull thistle, Cirsium vulgare
9. perennial sowthistle, Sonchus arvensis
10. whitetop = hoary cress = perennial peppergrass, Cardaria draba
11. Russian knapweed, Centaurea picris
12. spotted knapweed, Centaurea maculosa
13. leafy spurge, Euphorbia esula
14. quackgrass, Agropyron repens = Elytrigia repens
15. johnsongrass, Sorghum halapense, including sorghum almum and seed which cannot be distinguised from Johnsongrass
16. dodder, Cuscuta spp.
17. horsenettle, Solanum carolinense
18. yellow nutsedge, Cyperus esculentus, both seed and tubers
19. serrated tussock, Nasella trichoma

Restricted Noxious Weeds

1. fanweed, Thalspi arvense
2. black mustard, Brassica nigra
3. charlock, Sinapis arvensis
4. Indian mustard, Brassica juncea
5. wild radish, Raphanus raphanistrum
6. hoary alyssum, Berteroa incana
7. buckhorn plantain, Plantago lanceolata
8. wild carrot, Daucus carrota
9. wild onion, Allium canadense
10. wild garlic, Allium vineale
11. giant foxtail, Seteria faberii
12. yellow rocket, Barbarea vlugaris
13. curled dock, Rumex crispus
14. velvetleaf, Abutilon theophrasti
15. wild oat, Avena fatua
16. jimsonweed, Datura stramonium
17. cocklebur, Xanthium strumarium
18. nightshade complex, including all of the following Solanum species and any other species with indistinguishable seed:

1. bitter nightshade, Solanum dulcamara
2. black nightshade, Solanum nigrum
3. eastern black nightshade, Solanum ptycanthum
4. silverleaf nightshade, Solanum eleagnifolium
5. hairy nightshade, Solanum sarrachoid

Noxious weeds:
Act 359 of 1941 - Noxious Weeds - for control of noxious weeds

• Canada thistle, Cirsium arvense
• dodder, Cuscuta species
• mustards (charlock, black mustard, Indian mustard, species of Brassica or Sinapis)
• wild carrot, Daucus carrota
• bindweed, Convolvulus arvensis
• perennial sowthistle, Sonchus arvensis
• hoary alyssum, Berteroa incana
• ragweed, Ambrosia elatior
• poison ivy, Rhus toxicodendrum
• poison sumac, Toxicodendron vernix

Insect Pests and Plant Diseases:
Act 189 of 1931 Insect Pests and Plant Diseases

• Purple loosestrife - any non-native member of the genus Lythrum or hybrid of the genus are prohibited from sale.
• Barberry, mahonia or mahoberberis bushes subject to attack by black stem rust are prohibited.

Act 313 of 1929 White Pine Blister Rust

• prohibits planting of currants and gooseberries in certain parts of the State of Michigan