Information on proper herbicide use


By Ethan Proud
PREVIEW Columnist
Herbicides are the go-to method for weed control after mowing or manual removal. However, there are many considerations to take before selecting an herbicide.
Before purchasing an herbicide, whether it is a ready-to-use formulation or concentrate, you must read the label. The label is the law and deviating from the label instructions violates federal law.
Review the personal protection equipment (PPE) required, ensuring that you have access to such gear. Most herbicides require long-sleeved shirts, pants, socks, closed-toed shoes, gloves and eye protection. If an herbicide label has additional PPE, you must wear what the label instructs. When mixing two herbicides that are approved on the label as being tank compatible, you must follow the label that has the strictest regulations.
The label will also have environmental/agricultural concerns and regulations/restrictions. There may be grazing restrictions, stating that treated hay may not be sold for 18 months following treatment, or a time requirement between grazing on treated land and slaughter. Do not disregard these instructions.
The label will also list what weeds will be controlled and at what rates, as well as what rates desirable plants may be tolerant to the chemical. There will also be directions for how many applications are legal per year. Do not exceed the chemical rate or the number of treatments per year. By mixing at a higher or “hotter” rate than permitted, the efficacy of the herbicide is not increased, and damage to desirable plants is substantially greater.
Calibrating spray equipment is just as important and can be done following the 1/128 methods. Many herbicides have a spot-spraying rate and will be listed in the amount of chemical per gallon. By calibrating your equipment, you will follow rates much more accurately, waste less chemical and achieve a better level of weed control. Calibration should be done at a minimum of once per season and should be done each time a nozzle, hose, pump, etc. is replaced. It is important to use the same rate for each application of a specific herbicide. Plants develop a tolerance if a lower rate is used in subsequent applications.
Some species of plants may have a predisposition to gaining herbicide resistance and it is advisable to rotate between herbicides every three years. Better yet, use integrated management and remove the flowering heads of surviving plants and incorporate mechanical and cultural controls when managing weeds.
Archuleta County Weed and Pest is your local resource for managing noxious weed populations and controlling other pests.
Weed tour
The Archuleta County weed tour will take place on Saturday, June 16, from 9 a.m. to 1 p.m.
To register, email Ethan Proud at with the number of attendees and “Weed Tour” as the subject.
This opportunity is free and funded by grants; as such, there are a limited number spots available.
Babysitting classes
The babysitting class is full, but we are taking names for a second class that will be announced. Please call the Extension office to reserve your spot.
CPR and first aid classes
CPR and first aid certification classes are offered monthly by the Colorado State University Extension office on the second Monday and Wednesday of each month from 6 to 10 pm. Anyone needing to receive or renew certification can register by calling the Extension office at 264-5931.
We will also attempt to schedule classes on additional dates with five or more registrations. Cost for the classes is $80 for combined CPR/first aid and $55 for CPR, first aid or recertification. The type of first aid information provided will vary by the needs of the audience.