Yellow star thistle is an invasive weed that can quickly take over pastures, gardens, and natural landscapes if not controlled. The best herbicides for yellow star thistle help eliminate this aggressive plant, preventing it from competing with desirable vegetation and reducing its spread.

This guide reviews 10 top-performing herbicides that are specifically effective for controlling yellow star thistle. From selective herbicides that target only thistle to non-selective options that work on all weeds, these products offer reliable solutions for managing this troublesome weed.

Best Herbicides for Yellow Star Thistle

1. Milestone Herbicide

Milestone Herbicide is a selective herbicide that targets yellow star thistle effectively without harming desirable plants. It is designed to control broadleaf weeds, making it an excellent choice for landscapes and pastures where you want to protect grass.

Apply Milestone when yellow star thistle is actively growing for the best results. The herbicide works by interfering with the plant’s growth processes, ultimately killing it and preventing regrowth. It’s effective in both spring and fall applications.

This herbicide is highly regarded for its long-lasting effects and minimal environmental impact. Once applied, it ensures that yellow star thistle is controlled for an extended period, reducing the need for frequent applications.

2. Tordon 22K Herbicide

Tordon 22K Herbicide is a powerful selective herbicide that is highly effective against yellow star thistle. It works by targeting the plant’s root system, preventing regrowth after the initial application.

This herbicide is especially effective when applied during the early stages of yellow star thistle growth. It has a systemic action, meaning it is absorbed into the plant and travels through the roots to kill the entire plant.

Tordon 22K is ideal for use in larger areas like pastures, rangelands, and roadsides. It provides long-lasting control and can significantly reduce yellow star thistle populations with minimal environmental impact when applied correctly.

3. Crossbow Herbicide

Crossbow Herbicide is a broad-spectrum herbicide that works well on yellow star thistle, along with other woody and broadleaf plants. This product is ideal for use in areas where you need to clear out multiple types of vegetation, including thistles.

When applied, Crossbow is absorbed by the plant and moves through its vascular system, killing it from the roots up. It’s effective in treating established yellow star thistle plants, providing fast and thorough control.

Crossbow is highly effective when applied during the growing season. It’s also relatively easy to apply, making it a go-to solution for homeowners and professionals alike looking to control yellow star thistle in large areas.

4. Garlon 4 Herbicide

Garlon 4 Herbicide is a selective herbicide that is highly effective in controlling yellow star thistle. It works well in both forestry and non-crop areas, targeting broadleaf plants and woody vegetation.

Apply Garlon 4 directly to the foliage of yellow star thistle. The herbicide is absorbed through the leaves and moves into the roots to eliminate the plant. It can be used in areas where you want to preserve surrounding vegetation.

This herbicide is particularly effective in areas with dense vegetation, as it targets only the thistle and other undesirable plants. It’s ideal for spot treatments and larger applications, making it versatile for both small and large areas.

5. Chlorsulfuron Herbicide

Chlorsulfuron Herbicide is a systemic herbicide that targets yellow star thistle and other broadleaf weeds. It is an effective treatment for yellow star thistle in pastures, rangelands, and roadsides.

Chlorsulfuron works by inhibiting the plant’s ability to synthesize proteins, which ultimately leads to the plant’s death. The herbicide is absorbed by both the foliage and the roots, ensuring that yellow star thistle is eradicated.

For best results, apply this herbicide in early spring or late fall when the thistle is actively growing. Chlorsulfuron is known for its long-lasting effects, so it will continue to control yellow star thistle for several months after application.

6. PastureGuard Herbicide

PastureGuard Herbicide is a selective herbicide that is highly effective against yellow star thistle and other noxious weeds. It is particularly useful in pastures and rangelands, where thistle can cause serious competition for forage crops.

When applied to yellow star thistle, PastureGuard disrupts its growth cycle, killing it and preventing it from spreading. It targets the plant’s vascular system, which helps eradicate the plant from the root up.

PastureGuard is a great choice for use in grazing lands and can be applied during the growing season. It is also safe for use on many grass species, making it ideal for mixed-use areas.

7. Weed-B-Gon Weed Killer

Weed-B-Gon Weed Killer is a selective herbicide designed to target yellow star thistle and other broadleaf weeds. It is effective on both young and mature thistle plants, providing fast and reliable results.

Apply Weed-B-Gon directly to the leaves of yellow star thistle. The herbicide is absorbed into the plant, preventing regrowth and ultimately killing it. For best results, apply during the early stages of the growing season when the plant is actively growing.

This herbicide is easy to apply and provides excellent control of yellow star thistle without affecting surrounding plants. It’s ideal for use in lawns, gardens, and other landscapes where thistle is a problem.

8. Surflan A.S. Herbicide

Surflan A.S. Herbicide is a pre-emergent herbicide that can prevent the germination of yellow star thistle seeds. It works best when applied before the thistle seeds start to sprout, preventing future infestations.

Surflan creates a barrier that inhibits seedling growth, making it ideal for areas where yellow star thistle has been a recurring problem. It can be used in both agricultural and non-crop settings.

For the best results, apply Surflan A.S. in early spring before the thistle seeds begin to germinate. It’s a great option for long-term control of yellow star thistle and other weeds in untreated areas.

9. DuPont Method 240 Herbicide

DuPont Method 240 Herbicide is an effective solution for controlling yellow star thistle in a variety of environments. It works by targeting the plant’s metabolic functions, leading to its eventual death.

This herbicide is effective when applied to yellow star thistle during the early stages of growth. It has a rapid mode of action, providing quick results in controlling unwanted thistle populations.

DuPont Method 240 is ideal for use in larger agricultural areas and is often chosen for its cost-effectiveness in treating large swaths of land. It provides extended control, reducing the need for frequent reapplication.

10. Roundup Weed & Grass Killer

Roundup Weed & Grass Killer is a non-selective herbicide that is highly effective against yellow star thistle. It kills the plant by disrupting its cellular processes, causing it to die within days of application.

Roundup is best used in areas where you do not have desirable plants you want to protect. Apply it directly to the yellow star thistle for fast and thorough control. This herbicide works well on mature thistle plants.

Roundup is a go-to herbicide for tackling large-scale infestations of yellow star thistle. It’s versatile, affordable, and available in various formulations to meet different needs.

Buyer’s Guide

When choosing a herbicide for yellow star thistle, consider the following factors:

• Application Type: Some herbicides are for spot treatments, while others cover larger areas. Choose one that fits your needs.
• Effectiveness: Select a product known to work on yellow star thistle and offers lasting control.
• Environmental Impact: Consider herbicides that are safe for surrounding vegetation and wildlife.
• Cost: Compare prices and consider the long-term value based on the area you need to treat.

Conclusion

Yellow star thistle can be a serious problem, but with the right herbicide, you can control it effectively. Each of the 10 products listed here offers unique benefits, so consider your specific needs when selecting the best option. Whether you’re looking for a selective herbicide or a non-selective option, there’s a product on this list that can help you maintain a healthy, thistle-free environment.

Always follow the label instructions for safe and effective application of these herbicides to ensure the best results. Happy gardening!