Here's a quick overview of the treatments ISN has found most successful for controlling knotweeds:
Milestone (aminopyralid)
Faster kill (~3 years), more off-target effects
Standard rate (3-7 oz/acre; 0.01%)
Using nonionic surfactant (standard rate)
Late spring (3-4 ft high) or late summer (at least 60 days before frost)
When treating in late sum
Here's a quick overview of the treatments ISN has found most successful for controlling knotweeds:
Milestone (aminopyralid)
Faster kill (~3 years), more off-target effects
Standard rate (3-7 oz/acre; 0.01%)
Using nonionic surfactant (standard rate)
Late spring (3-4 ft high) or late summer (at least 60 days before frost)
When treating in late sum