Corn gluten meal is largely ineffective at suppressing perennial plant species such as field horsetail.
What is the solution to get rid of horsetail out of the flower bed and I have noticed that it is in my lawn. Any help would be greatly appreciated. Thanks
In flower beds the use of Casaron can be helpful to slowly suppress horsetail over time. I have pasted the standard recommendation from the PNW Weed Management Handbook below. This product is commonly available. The other option is to dig out the plants and impacted soils and dispose of the material. I am not aware of any useful controls in turf, but it doesn't tolerate frequent mowing.
Rate 4 lb ai/A granular formulation
Time Apply in winter or early spring, when moisture is available to leach chemical into soil. In landscape plantings, apply any time and place bark mulch over the treated area to reduce volatilization.
Remarks Good selective control in many fruits and ornamental plants. Use as a follow-up, supplemental treatment if horsetail resists many soil-applied herbicides. Can apply over labeled ornamental plants or conifer tree nurseries. Apply midwinter immediately before a cold rain to reduce volatility and enhance weed suppression. Weigh and distribute uniformly exact quantities over precisely measured areas. Oregon results over 9 years suggest that perennial weeds can be suppressed with 4-, 3-, and 2-lb ai/A rates applied in 3 consecutive years. Grazing livestock is prohibited. (Inhibits cellulose and cell wall formation.)
Caution See label for precautions on ornamental species and varieties tolerant of dichlobenil.
Site of action Group 20: inhibits cell wall synthesis Site A
Chemical family Nitrile