Common Fennel

• Escapes cultivation and quickly establishes dense infestations that crowd out native plants that are critical to wildlife habitats.
• May pose a threat to native grasslands.

• A large, aromatic, perennial herb.
• Can grow up to 6.7 feet tall (2 meters) and has a very large taproot.
• Foliage, stems, roots and seeds are hairless and all have a very strong licorice scent.
• Flowers are small and yellow and form an umbrella shaped cluster.
• Plants bloom from May to September.
• Leaves have an overall triangular shape and are many times divided into thin, featherlike leaflets and are dark green or bronze.
• Leaf stems (petioles) are swollen and fleshy and have a widened base.
• Stems are upright and branched.
• Seeds are about 0.15 inches (3.5 to 4 mm) long and have small ridges.

• Found along roadsides, in pastures, prairies, streamsides, coastal bluffs as well as wetland areas..

• Reproduces from seed.
• Can also reproduce from pieces of the root crown.

• Can be controlled using mechanical techniques as well as herbicides.
• Small infestations can be hand pulled but mature plants are difficult to remove because of the taproot.
• Above ground growth can be repeatedly cut prior to flowering to deplete below ground energy reserves. This technique may need to be down for several years to be successful.
• Cutting above ground growth when flowers are present may promote seed dispersal.

2, 4-D amine

• Spot treatment: 0.25 to 0.5% solution
• Apply in spring to fully-grown leaves but prior to flowering.
• 2, 4-D is usually not able to fully control common fennel, so combining with other products is generally recommended. Retreatment will likely be necessary.
• Avoid drift to sensitive crops.

Glyphosate

• Rate: 2.8 lb ae/a
• Apply in spring to fully-grown leaves but prior to flowering.
• Adequate foliar coverage of fennel foliage is necessary. Add nonionic surfactant if not included in the formulation.
• Glyphosate is nonselective and injures or kills other vegetation in the treated area.

Triclopyr

• Broadcast treatment: 1 to 2 lb ae/a; spot treatment: 0.5 to 1% solution.
• Apply in spring to fully-grown leaves but prior to flowering.
• Do not drift onto sensitive crops.
• Do not contaminate water.