Monterey Thistledown

Monterey Thistledown, manufactured by Monterey, is a very strong post-emergent herbicide concentrate that offers selective weed control in rangelands, permanent grass pastures, and other non-crop areas. 

Formulated with the active ingredient clopyralid 40.90%, which makes it easy for ranchers and livestock managers to control weeds like Canada thistle, kudzu, and knapweed. 

Monterey Thistledown is a full-strength selective herbicide that manages difficult broadleaf weed infestations, helping to maintain the aesthetic appeal of rangelands, ranchette pastures, and more. Additionally, this product helps to maintain a healthy, weed-free environment for livestock with minimal grazing restrictions. 

Tools Needed

A handheld pump sprayer, backpack sprayer, or spray rig can be used. 

How to Use

• Step 1: Determine how much Monterey Thistledown to use by measuring the square footage of the treatment area. To do this, measure the length and width of the treatment area in feet then multiply them together (length X width = square footage). General applications on rangelands, permanent pastures, and ranchette pastures use 1/8 to 1/2 fl. oz. of Monterey Thistledown in 2 gallons of water per 1,000 sq. ft. For utility rights-of-ways, roadsides, and other non-crop areas, apply 1/2 fl. oz. of product in 1-2 gallons of water per 1,000 sq. ft. Refer the label for specific rates and restrictions. 
• Step 2: Add half of the required water to the spray tank and start agitation. Add the required amount of this product. Pour in the remaining half of water. Agitate until solution is well-mixed and during spraying. 
• Step 3: Spray the top and bottom of weeds until wet, but not to the point of runoff. 

Where to Use

Areas that may be treated can be in rangeland and permanent grass pastures (including but not limited to ranchette pastures), and in non-crop land areas including equipment pathways, industrial manufacturing and storage sites and rights-of-way such as along roadsides, electrical lines and railroads. Use on these sites may include application to grazed areas. 

This product can affect susceptible broadleaf plants directly through foliar contact and indirectly by root uptake from soil in treated areas.

Do not allow spray drift to come in contact with vegetables, flowers, tomatoes, potatoes, beans, lentils, peas, alfalfa, sunflowers, soybeans, safflower, or other desirable broadleaf crops or ornamental plants or soil where sensitive crops will be planted the same season.

When to Use

Best results on most weeds are obtained when weeds are small and actively growing. 

Established grasses are tolerant to this product but newly seeded grasses may be injured until well established as indicated by tillering, development of a secondary root system, and vigorous growth. 

Safety Information

Monterey Thistledown is safe to use around children and pets when applied according to the product label instructions. Always wear the proper personal protective equipment (PPE) when mixing and applying this product. 

Keep people and pets of out treated areas until the spray has completely dried. 

Special Considerations

Do not transfer livestock from treated grazing areas to sensitive broadleaf crop areas without first allowing 7 days of grazing on an untreated pasture. If livestock are transferred within less than 7 days of grazing untreated pasture, urine and manure may contain enough clopyralid to cause injury to sensitive broadleaf plants.

Do not use plant residues, including hay or straw from treated areas, or manure or bedding straw from animals that have grazed or consumed forage from treated areas for composting or mulching where susceptible plants may be grown the following season. Plant materials and/or manure contain enough clopyralid to cause injury to susceptible plant species