Johnson grass presents a persistent challenge in landscapes, gardens, and beds. The right herbicide targets grassy weeds without heavily injuring desirable ornamentals and nearby vegetation. The following selections are among the most relevant options for controlling Johnson grass and other stubborn grasses, spanning selective postemergence formulas, non-selective glyphosate concentrates, and organic-oriented solutions. This guide highlights each product’s core features, application notes, and usage considerations to help you choose a suitable option for your specific situation.
| Product | Brand | Key Features |
|---|---|---|
| Gordon’s Ornamec 170 Grass Herbicide, 32 Ounces | PBI / Gordon | Selective control of emerged annual grasses; reduces ornamental plant injury; designed for landscape beds. |
| Hi-Yield (31134) Grass Killer Postemergence Grass Herbicide (8 oz) | Hi-Yield | Selective post-emergent grass killer; can be applied around gardens and ornamentals; rapid growth suppression. |
| Hi-Yield (22742) Herbicide Granules Weed and Grass Preventer (4 lbs.) | Hi-Yield | Season-long prevention; prevents grass and weed growth when applied early; broad list of covered species. |
| Compare-N-Save Glyphosate Concentrate Grass & Weed Killer Herbicide, 16-ounce | Compare-N-Save | Glyphosate-based non-selective killer; rapid rainproof performance; makes up to 10 gallons of ready-to-use spray. |
| Monterey Grass Getter Bundled with Measuring Spoon – 8 oz | Monterey | Post-emergence, selective grass kill; broad effectiveness on common grassy weeds; not for lawn use; can be applied over listed ornamentals. |
Note: Each product has its own safety and application guidelines. Always read the label for resistance management, mixing instructions, and compatibility with nearby plants. The following reviews summarize practical considerations for American gardeners dealing with Johnson grass and similar stubborn grasses.
Gordon’s Ornamec 170 Grass Herbicide Review
Product overview: Gordon’s Ornamec 170 is a selective grass herbicide designed for maintenance in landscape beds. It targets emerged annual grasses while minimizing injury to ornamental plants. The product is suitable for use around plantings and features a formulation intended to reduce collateral damage, which is particularly valuable when Johnson grass grows among ornamentals.
Key features: Selectively controls annual grasses such as panicums, goosegrass, crabgrass, foxtails and sandbur; designed to reduce ornamental injury risk; suitable for landscape beds. For Johnson grass, this can be a practical option where grass control is needed without affecting desirable ornamentals. Users should apply according to label directions and be mindful of surrounding plant tolerance. Overall, Ornamec 170 provides targeted grassy weed suppression in mixed plant scenarios.
Hi-Yield Grass Killer Postemergence Review
Product overview: This postemergence herbicide from Hi-Yield focuses on actively growing grasses. It is designed for selective action, allowing application around vegetables, trees, shrubs, and ornamentals with safety in mind, while rapidly stopping weed grass growth within days of treatment.
Key features: Targets and kills grass growth; can be applied safely around vegetables and ornamentals; observable suppression begins within a couple of days. For Johnson grass encroaching near garden beds or ornamentals, this product offers a postemergence option that emphasizes selectivity and timely results. Always follow label directions and test on a small area if unsure about neighboring plants.
Hi-Yield Herbicide Granules Review
Product overview: This granulated pre-emergent herbicide is designed to prevent weed and grass growth for the season when applied at the start. It covers a broad spectrum including common grasses associated with Johnson grass challenges.
Key features: Prevents grass and weed growth all season; useful when starting a growing season; controls bluegrass, crabgrass, and more per label. While not a postemergence solution, its preventative approach can complement other treatments in a comprehensive Johnson grass management plan. Follow label instructions for timing and application rates.
Compare-N-Save Glyphosate Concentrate Review
Product overview: This non-selective glyphosate concentrate provides broad weed control and is widely used for tougher grasses like Johnson grass when relative safety to nearby ornamentals is less of a concern. It enables users to mix up to a ready-to-use spray and offers a rainproof window after application.
Key features: 41% glyphosate content; rainproof in about 2 hours; makes up to 10 gallons of ready-to-use spray; effective against a wide range of grasses and weeds. It is most suitable for tough grass invasions in open areas or where non-selective control is acceptable within the treatment zone. Always apply with care near desirable plants and follow label directions for rate and re-entry intervals.
Monterey Grass Getter Review
Product overview: Grass Getter is a post-emergence herbicide designed to control grassy weeds in ornamentals, bedding plants, and other non-lawn areas. It is a selective herbicide intended to spare many ornamentals when used as directed, with emphasis on systemic uptake to reach grassy roots.
Key features: Postemergence grass killer; controls a variety of grassy weeds including crabgrass, bermudagrass, foxtail, and Johnson grass types; can be sprayed over the top of listed ornamentals; not for lawn use. This makes it suitable for beds and borders where Johnson grass intrudes among ornamentals. Users should apply precisely as labeled and avoid sensitive plants not listed on the label.
Buying Guide: Key Purchase Considerations
When selecting an herbicide to control Johnson grass, consider the following factors to ensure effective management while protecting non-target plants and the environment.
- Mode of action: Postemergence herbicides kill actively growing grasses, while pre-emergents prevent seed germination. For Johnson grass, postemergence products are often essential, but combining with a pre-emergent can improve long-term control.
- Selectivity: If your Johnson grass grows among ornamentals or in garden beds, choose a selective product that minimizes damage to desirable plants. Non-selective glyphosate is effective but requires careful spraying to avoid collateral injury.
- Application area: Determine whether the target area is a lawn, garden bed, or landscape border. Some products are not suitable for lawns but perform well in beds and around ornamentals.
- Active ingredients: Glyphosate offers broad-spectrum weed killing, while selective products like Ornamec or Grass Getter focus on grasses with reduced impact on ornamentals. Understand your weed spectrum to choose appropriately.
- Re-entry and safety: Always observe re-entry intervals, protective equipment recommendations, and any cautions about pollinators or pets near treated areas.
- Seasonal timing: Pre-emergent options are best early in the season, while postemergents require existing weed growth. Align your treatment with the Johnson grass growth stage for maximum effect.
- Long-term management: Johnson grass can be persistent. Integrated approaches—herbicides, mulching, irrigation management, and manual removal—often yield the best outcomes over multiple seasons.
These considerations help ensure you pick a product that aligns with your landscape, plant sensitivities, and environmental goals. Always follow the product label for accurate mixing, application rates, and safety precautions.