Best Herbicide for Blackberries – Reviews and Buyer’s Guide [March 2022]

Blackberries are perennial and biennial weeds native to the United States and commonly found in the state of Florida. They are characterized by a deep root network that spreads in the ground creating new shoots. If not controlled, this weed can colonize the pasture by growing into a thick bush. The best control mechanism for this weed is by entirely eliminating the root system to prevent regrowth.

Despite selecting the best herbicide, it is also prudent to consider other crucial factors like the rate, frequency, and correct application time. Once you get this right, you can be guaranteed a blackberry-free greensward. This article discusses the best considerations when applying herbicides to kill blackberries. They include:

1. The top 5 herbicides for blackberries 
2. The correct time to apply herbicide to blackberries 
3. How to apply herbicides on blackberries 
4. How to calculate the herbicides application area
5. Choosing the best herbicide for blackberries 

The Top Five Herbicides for Blackberries

Parameter	Southern Ag Crossbow	Roundup Concentrate	Roundup Quick Pro	Southern Ag Brush Killer	Speed Zone Broadleaf Herbicide
Active ingredient	Copperammoniadiacetate	Glyphosphate isopropylamine salt and triclopyr triethylamine salt	Glyphosate ammonium salt  and diquat dibromide	Triclopyr	Cafentrazone-ethyl, 2-Ethylhexyl ester, Mecoprop p-acid, and Dicamba acid
Action time	Within a week	1 – 2 days	3 – 5 days	1 – 6 weeks	1 – 2 weeks
Application rate	Mix 5 fl. oz. in 3 gallons of water	Mix 6 fl. oz. of concentrate with 1 gallon of water	Make a solution of 1.5fl. Oz. with 1 gallon of water	4 – 8 oz per gallon of water	1.5 – 2.4 fl. oz into1 gallon of water for 1000sq  ft
Time to apply	Between March and June	Between March and June	Active growth season from March and April	From March to April	Between September and December
Application directions	Spray herbicide before and after agitation	Spray on the target plant in calm weather	Dispense the herbicide solution on the target weed	Use tank or hose-end sprayer to dispense the liquid to the targeted plant	Dilute with water or liquid fertilizer and spray

Southern AG Crossbow – Best Weedkiller for Blackberry 

This herbicide is specially formulated with copper ammonia acetate, which permeates the weeds tissue and kills it from within. It is effective on a wide range of weeds, including moss, algae, and blackberries. The herbicide should be used within six months after purchase due to its short shelf life. 

To effectively eliminate blackberries, spray the solution on the entire plant: from the base to the foliage. Ensure you mix the herbicide in the correct proportion with water and a surfactant to increase its adhesiveness and prevent wash off by the rain. Wear protective clothing when applying as it is harmful if inhaled or ingested.

Pros 

• Kills a wide range of herbicides 
• Does not harm vegetables 
• Short time of action 

Cons 

• Susceptible to wash off without surfactant 

Roundup Concentrate – Best Economical Weed Killer for Blackberries 

Roundup concentrates packs the power of two active ingredients delivering a tandem effect to killing the weeds. In its kill list includes; invasive vines, shrubs, weeds, and wild berries like blackberries. It penetrates and kills the roots of the plants ensuring they do not reappear. This herbicide becomes rainproof in 30 minutes, preventing wash off by water. 

This weed has a quick action time of 1 – 2 days. Additionally, it is convenient for large-area applications giving great value for your money. Ensure to spray the herbicide in a cool and calm environment to prevent drift by the wind. If results are not visible in a month, reapply the weed.

Pros 

• Kills weeds to the root
• Effective within day
• Economical 

Cons 

• Susceptible to the wind 

Roundup Quick Pro – Water-Soluble Herbicide Granule for Blackberries

Roundup is a water-soluble granular herbicide effective against post-emergent perennial, biennial, broadleaf, grassweeds, and blackberries. This herbicide offers double action against weeds from its two active ingredients. It is combined with a surfactant to adhere to the plant surface for faster absorption. 

Round up becomes rainfast in 60 minutes preventing wash off after application. The herbicide permeates the plant to the roots, where it completely kills it. It is supplied in an easy-to-handle granular form and a measuring lid for accurate preparation. It is a non-selective weed killer hence caution should be exercised during application. 

Pros 

• Less dry time
• Fast uptake
• Kills the root completely 

Cons 

• Non-selective weed killer 

Southern Ag Brush Killer – Best Broadleaf and Woody Plants Killer 

Southern Ag is effective against a broad range of herbs, including blackberries, cherry, cottonwood, and Kudzu. It is approved for use in non-crop areas to kill and prevent the growth of weeds. 

Its recommended application time is a non-windy sunny day to prevent wash off and drift to the wanted vegetation. Wilting of herbicides manifest within 1 – 6 weeks post-application. This herbicide is a health hazard and therefore advised to be kept out of reach of children and not sprayed of edible crops. 

Pros 

• Effective against multiple weeds 
• Easy application 
• Prevents regrowth 

Cons 

• Harmful to non-target crops 

Speed Zone Broadleaf Herbicide – Best Selective Warm and Cool Season Herbicide 

Speedzone, synonymous with its name, provides quick action against broadleaf weeds both in the cool and warm seasons. It is effective against tough weeds like blackberries, ground ivy, clovers, and spurge. This low-odor herbicide works by hindering the production of a key enzyme in chlorophyll production hence starving the plant to death via cell lysis. 

The results manifest within one or two weeks of the application. Additionally, it becomes resistant to wash off three hours after application, increasing contact time with the plant for effective action. You can reseed your lawn week post-application of the herbicide. 

Pros 

• Reduced action time 
• Suitable for both cold and warm season 
• Wash off resistance in 4 hours 

Cons 

• Harmful to water bodies 

Buyer’s Guide and FAQ

What Is the Best Herbicide for Blackberries?

Due to this weed’s toughness and re-emergence characteristics, the best herbicide here needs to have the ability to kill the weed plus its roots completely. Herbicides with triclopyr, glyphosate, metsulfuron, and fluroxypyr active ingredients are most effective.

How to Apply Herbicide to Blackberries?

The general procedure includes mixing the herbicide in the required ratio with water and/or other additives. Then, using the appropriate dispensing tool, spray the solution to the target area. If need be, wear protective clothing. 

When to Spray Blackberries With Herbicide?

The best time to kill blackberries is during their season of active growth. This is done mostly in the Spring or late Fall when the plant is loading energy from the leaves to the roots; hence the herbicide permeates the roots plus the weather conditions are usually favorable for spraying. 

How Soon After Herbicide Application Can I Mow Blackberries?

Mowing is recommended when the plant begins to wilt, showing some signs of the herbicide effect. Ensure the mower is sharp enough to cut off the stem of the plant and eliminate leaves. The roots will starve and die from herbicide effects and lack of food.

How to Calculate How Much Herbicide Is Needed?

First, you must know the application rate of the herbicide in its concentrated or diluted form. For example, for a 5 pound per acre herbicide, then you would need 5 pounds for every acre of land. To get what is needed for less or more land, simply divide or multiply the area by the pound per acre rate respectively. 

Final Thought 

Blackberries are one of the toughest weeds to eliminate since their root system spreads underground and sprouts into new shoots. They often need powerful herbicides that will kill the entire plant, including the roots, for effective control. Watch out for effective herbicides with lethal active ingredients against blackberries for excellent control of this weed.