Zinnias are vibrant, colorful flowers that add beauty to gardens, landscapes, and flower beds. However, weeds can compete with zinnias for nutrients, water, and sunlight, hindering their growth and blooming.
Choosing the best herbicide for zinnias is crucial to ensure these flowers thrive without being overshadowed by invasive weeds.
This article provides an in-depth review of the 10 best herbicides for zinnias, along with tips for selecting the right product.
On This Page Expect To Learn
Tips for Choosing the Best Herbicide for Zinnias
- Identify the Weeds: Determine the types of weeds in your garden to select an herbicide that targets them effectively.
- Check Compatibility: Ensure the herbicide is safe for zinnias and won’t harm their growth or blooming.
- Consider the Application Method: Choose between pre-emergent (prevents weed seeds from germinating) and post-emergent (kills existing weeds) herbicides.
- Read Labels: Look for active ingredients like glyphosate, trifluralin, or fluazifop, which are effective yet safe for ornamental plants.
- Environmental Impact: Opt for eco-friendly herbicides to protect pollinators and beneficial insects.
- Ease of Use: Select a formulation (liquid, granular, or ready-to-use) that suits your gardening style.
- Budget: Compare prices and coverage to find a product that offers the best value.
Best Herbicide for Zinnias: A Comprehensive Guide
1. Preen Garden Weed Preventer – Best Pre-Emergent Herbicide for Zinnias
Preen Garden Weed Preventer is a top-rated pre-emergent herbicide that prevents weeds from germinating around zinnias. Its active ingredient, trifluralin, creates a barrier in the soil to stop weed growth. This granular formulation is easy to apply and provides long-lasting protection.
The herbicide is safe for zinnias and other ornamental plants, ensuring they grow without competition from weeds. It is rainproof within 24 hours, making it reliable even in wet conditions. Preen Garden Weed Preventer covers up to 500 square feet per bottle, making it ideal for small to medium gardens.
For best results, apply Preen Garden Weed Preventer in early spring before weeds emerge. Reapply every 9-12 weeks for continuous protection.
Pros:
- Prevents weed germination
- Safe for zinnias
- Rainproof in 24 hours
- Granular formula
- Long-lasting protection
- Easy to apply
- Affordable
Cons:
- Not for existing weeds
- Requires reapplication
- May harm some plants
2. Roundup Ready-To-Use Weed & Grass Killer – Best Post-Emergent Herbicide for Zinnias
Roundup Ready-To-Use Weed & Grass Killer is a powerful post-emergent herbicide that targets weeds around zinnias without harming the flowers. Its active ingredient, glyphosate, kills weeds on contact. This ready-to-use formula is convenient and easy to apply.
The herbicide provides visible results within 12 hours, with complete weed elimination in 7-10 days. It is rainproof within 30 minutes, ensuring reliable performance. Roundup Ready-To-Use is ideal for spot treatments in small gardens.
For best results, apply Roundup Ready-To-Use directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Kills weeds on contact
- Safe for zinnias (when used carefully)
- Rainproof in 30 minutes
- Ready-to-use formula
- Fast results
- Easy to apply
- Affordable
Cons:
- Non-selective (can harm desirable plants)
- Requires careful application
- Strong chemical odor
3. Ortho GroundClear Vegetation Killer – Best Herbicide for Zinnias in Large Gardens
Ortho GroundClear Vegetation Killer is a long-lasting herbicide that kills weeds and prevents regrowth for up to 1 year. Its active ingredients, glyphosate and imazapyr, provide comprehensive weed control. This ready-to-use formula is ideal for large gardens.
The herbicide is safe for use around zinnias when applied carefully. It provides visible results within 3 hours, with complete weed elimination in 1-2 weeks. Ortho GroundClear is rainproof within 1 hour, ensuring consistent performance.
For best results, apply Ortho GroundClear directly to weeds, avoiding contact with zinnias. It is ideal for driveways, walkways, and garden edges.
Pros:
- Long-lasting weed control
- Safe for zinnias (when used carefully)
- Rainproof in 1 hour
- Ready-to-use formula
- Fast results
- Covers large areas
- Easy to apply
Cons:
- Non-selective (can harm desirable plants)
- Requires careful application
- Higher price point
4. Spectracide Weed & Grass Killer – Best Herbicide for Zinnias in Small Gardens
Spectracide Weed & Grass Killer is a fast-acting herbicide that targets weeds around zinnias without harming the flowers. Its active ingredient, fluazifop, kills weeds on contact. This ready-to-use formula is convenient and easy to apply.
The herbicide provides visible results within 3 hours, with complete weed elimination in 1-2 weeks. It is rainproof within 1 hour, ensuring reliable performance. Spectracide Weed & Grass Killer is ideal for small gardens and spot treatments.
For best results, apply Spectracide Weed & Grass Killer directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Kills weeds on contact
- Safe for zinnias (when used carefully)
- Rainproof in 1 hour
- Ready-to-use formula
- Fast results
- Easy to apply
- Affordable
Cons:
- Non-selective (can harm desirable plants)
- Requires careful application
- Strong chemical odor
5. Bonide BurnOut Weed & Grass Killer – Best Organic Herbicide for Zinnias
Bonide BurnOut Weed & Grass Killer is an organic herbicide that uses natural ingredients like clove oil and citric acid to kill weeds around zinnias. This eco-friendly formula is safe for zinnias and the environment.
The herbicide provides visible results within 24 hours, with complete weed elimination in 1-2 weeks. It is rainproof within 2 hours, ensuring reliable performance. Bonide BurnOut is ideal for organic gardeners and those concerned about pollinators.
For best results, apply Bonide BurnOut directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants and edible gardens.
Pros:
- Organic and eco-friendly
- Safe for zinnias
- Rainproof in 2 hours
- Ready-to-use formula
- Fast results
- Easy to apply
- Safe for pollinators
Cons:
- Requires frequent reapplication
- Higher price point
- Not for large infestations
6. Compare-N-Save Concentrate Grass and Weed Killer – Best Herbicide for Zinnias in Large Infestations
Compare-N-Save Concentrate Grass and Weed Killer is a cost-effective herbicide that targets weeds around zinnias in large infestations. Its active ingredient, glyphosate, kills weeds on contact. This liquid concentrate is easy to mix and apply.
The herbicide provides visible results within 12 hours, with complete weed elimination in 7-10 days. It is rainproof within 2 hours, ensuring reliable performance. Compare-N-Save covers up to 25,000 square feet per bottle, making it ideal for large gardens.
For best results, apply Compare-N-Save directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Cost-effective
- Kills weeds on contact
- Safe for zinnias (when used carefully)
- Rainproof in 2 hours
- Covers large areas
- Easy to mix
- Fast results
Cons:
- Non-selective (can harm desirable plants)
- Requires careful application
- Strong chemical odor
7. Southern Ag Amine 2,4-D Weed Killer – Best Herbicide for Zinnias in Broadleaf Weed Control
Southern Ag Amine 2,4-D Weed Killer is an affordable herbicide that targets broadleaf weeds around zinnias. Its active ingredient, 2,4-D, effectively kills weeds without harming zinnias. This liquid concentrate is easy to mix and apply.
The herbicide provides visible results within 7-10 days, with complete weed elimination. It is rainproof within 4 hours, ensuring reliable performance. Southern Ag Amine 2,4-D covers up to 6,000 square feet per bottle, making it ideal for medium to large gardens.
For best results, apply Southern Ag Amine 2,4-D directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Affordable
- Kills broadleaf weeds
- Safe for zinnias
- Rainproof in 4 hours
- Covers 6,000 sq. ft.
- Easy to mix
- Fast results
Cons:
- Requires mixing
- Strong odor
- Not for grassy weeds
8. Gordon’s Trimec Lawn Weed Killer – Best Professional-Grade Herbicide for Zinnias
Gordon’s Trimec Lawn Weed Killer is a professional-grade herbicide that targets broadleaf weeds around zinnias. Its active ingredients, 2,4-D, MCPP, and dicamba, ensure comprehensive weed control. This liquid concentrate is easy to mix and apply.
The herbicide provides visible results within 7-10 days, with complete weed elimination. It is rainproof within 4 hours, ensuring consistent performance. Gordon’s Trimec covers up to 10,000 square feet per bottle, making it ideal for large gardens.
For best results, apply Gordon’s Trimec directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Professional-grade
- Kills broadleaf weeds
- Safe for zinnias
- Rainproof in 4 hours
- Covers 10,000 sq. ft.
- Easy to mix
- Fast results
Cons:
- Higher price point
- Requires mixing
- Strong chemical odor
9. Image All-in-One Lawn Weed Killer – Best Herbicide for Zinnias in Stubborn Infestations
Image All-in-One Lawn Weed Killer is a potent herbicide designed to eliminate stubborn weeds around zinnias. Its active ingredient, imazaquin, targets weeds without harming zinnias. This ready-to-spray formula is easy to use.
The herbicide provides visible results within 7-10 days, with complete weed elimination. It is rainproof within 2 hours, ensuring consistent performance. Image All-in-One covers up to 5,000 square feet per bottle, making it suitable for medium to large gardens.
For best results, apply Image All-in-One directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Kills stubborn weeds
- Safe for zinnias
- Rainproof in 2 hours
- Ready-to-spray formula
- Fast results
- Covers 5,000 sq. ft.
- Easy to use
Cons:
- Higher price point
- May require reapplication
- Strong chemical odor
10. Monterey LG 5600 Spurge Power – Best Herbicide for Zinnias in Spurge Control
Monterey LG 5600 Spurge Power is a specialized herbicide that targets spurge and other tough weeds around zinnias. Its active ingredient, triclopyr, effectively kills weeds without harming zinnias. This liquid concentrate is easy to mix and apply.
The herbicide provides visible results within 7-10 days, with complete weed elimination. It is rainproof within 4 hours, ensuring reliable performance. Monterey LG 5600 covers up to 5,000 square feet per bottle, making it ideal for medium to large gardens.
For best results, apply Monterey LG 5600 directly to weeds, avoiding contact with zinnias. It is safe for use around ornamental plants when used as directed.
Pros:
- Kills spurge effectively
- Safe for zinnias
- Rainproof in 4 hours
- Easy to mix
- Fast results
- Covers 5,000 sq. ft.
- Affordable
Cons:
- Requires mixing
- Strong odor
- Not for all weed types
Buyer’s Guide for the Best Herbicide for Zinnias
Tips for Choosing the Best Herbicide for Zinnias
- Choose a Selective Herbicide — Opt for a herbicide specifically designed to target weeds without harming zinnias. Look for selective formulas compatible with ornamental plants.
- Check Active Ingredients — Ensure the herbicide contains proven ingredients like glyphosate, trifluralin, or fluazifop, as they effectively combat weeds while being safe for zinnias.
- Pre-Emergent vs. Post-Emergent — Select a herbicide based on your need—pre-emergents prevent germination, while post-emergents tackle already established weeds.
- Consider Application Method — Whether using a spray or granular herbicide, choose one that suits your equipment and coverage area for better efficiency.
- Look for Long-Lasting Control — Choose a herbicide with residual control properties to prevent regrowth and maintain a weed-free garden for longer.
- Eco-Friendly Options — For environmentally conscious buyers, select a bio-based herbicide that minimizes harm to non-target plants and soil health.
- Check for Rainfastness — Ensure your chosen herbicide is rainproof within a few hours to prevent wash-off and guarantee maximum effectiveness after application.
By following these tips, you can confidently select the best herbicide for zinnias and maintain a vibrant, weed-free garden.
FAQs About the Best Herbicide for Zinnias
- Can I use any herbicide on zinnias?
No, always choose herbicides labeled as safe for ornamental plants like zinnias. - When is the best time to apply herbicide for zinnias?
Apply pre-emergent herbicides in early spring and post-emergent herbicides during active weed growth. - How often should I apply herbicide for zinnias?
Follow the product label instructions, but most herbicides require reapplication every 4-6 weeks. - Can herbicides harm zinnias?
Some herbicides can harm zinnias if not used correctly. Always read the label and follow instructions. - What is the difference between pre-emergent and post-emergent herbicides?
Pre-emergent herbicides prevent weed seeds from germinating, while post-emergent herbicides kill existing weeds. - Are organic herbicides effective for zinnias?
Yes, but they may require more frequent applications compared to synthetic herbicides. - Can I mix herbicides with fertilizers?
Yes, some products combine herbicides and fertilizers for convenience.
Conclusion
Choosing the best herbicide for zinnias is essential for maintaining a healthy, weed-free garden. After reviewing the top 10 products, Preen Garden Weed Preventer stands out as the best pre-emergent herbicide for preventing weeds, while Roundup Ready-To-Use Weed & Grass Killer is the top post-emergent option for killing existing weeds.
For organic gardeners, Bonide BurnOut Weed & Grass Killer is an excellent eco-friendly choice.
By following the tips and recommendations in this guide, you can ensure your zinnias thrive without competition from invasive weeds. Invest in the right product, apply it correctly, and enjoy a vibrant, colorful garden that’s the envy of your neighborhood
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