Management of Problem Biennial Species

1
Management of Problem Biennial Species
2
Examples

• Poison hemlock
• Musk thistle
• Bull thistle
• Pluemeless thistle
• Teasel
• Wild parsnip

3
Management Factors

• Prevent seed set
• Implement control prior to bolt

4
Control Measures

• Mowing
• Not effective prior to bolt due to rosette growth
  habit
• Plant will regrow, reduced seed set, shorter seed
  stalk
• Only too-frequent mowing can prevent seed set

5
Control Measures

• Mowing
• Not effective prior to bolt due to rosette growth
  habit
• Plant will regrow, reduced seed set, shorter seed
  stalk
• Only too-frequent mowing can prevent seed set

6
Control Measures

• Mowing
• Not effective prior to bolt due to rosette growth
  habit
• Plant will regrow, reduced seed set, shorter seed
  stalk
• Only too-frequent mowing can prevent seed set

7
Herbicides - Timing

• Post-Krenite to November 1
• Tax day to May 15

8
Herbicides - Mixes

• Crownvetch - Velpar
• Turf - Garlon/Escort, Garlon/Vanquish,
  Vanquish/Escort
• One Mix Fits All - Garlon/Vanquish
• Better to injure crownvetch than grass - will
  recover due to early timing

9
Herbicides - Mixes

• Crownvetch - Velpar
• Turf - Garlon/Escort, Garlon/Vanquish,
  Vanquish/Escort
• One Mix Fits All - Garlon/Vanquish
• Better to injure crownvetch than grass - will
  recover due to early timing

10
Herbicides - Mixes

• Crownvetch - Velpar
• Turf - Garlon/Escort, Garlon/Vanquish,
  Vanquish/Escort
• 'One Mix Fits All' - Garlon/Vanquish
• Better to injure crownvetch than grass - will
  recover due to early timing

11
Herbicides - Application

• Narrow(er) ROW - gun
• Limited Access - backpack or hose

12
Results

• Control of larger patches - easy to spot
• Miss smaller patches, individual plants
• Biennials are relatively small, compared to brush
  or knotweed

13
Results

• Control of larger patches - easy to spot
• Miss smaller patches, individual plants
• Biennials are relatively small, compared to brush
  or knotweed