Want Stronger Weed Killer?
Professional-grade herbicides often look appealing, but many require qualifications to buy and use. Here’s what actually makes them different, what you need a certificate for, and whether consumer products can do the same job.
Professional vs Consumer: What’s Actually Different?
The term “professional strength” suggests a more powerful product, but the reality is more nuanced. Here’s what genuinely differs between professional and consumer-grade herbicides:
The biggest practical difference is usually the surfactant system (the chemicals that help the herbicide spread across and penetrate leaf surfaces). Professional formulations typically include more effective surfactants, which can improve performance by 10-20% compared to a basic consumer product with the same active ingredient concentration.
PA1 and PA6 Certificates Explained
The UK pesticide certification system is managed by City & Guilds through the NPTC scheme. Here’s what the key certificates cover:
Do you need a certificate for your own garden? No. The certification requirement applies only to commercial use — applying pesticides as part of a business or on someone else’s property for payment. You can legally buy and use consumer-grade pesticides in your own garden without any qualifications. However, you cannot buy professional-use-only products without the relevant certificates.
What You Can and Can’t Buy Without a Certificate
In the UK, pesticide products are classified into two main categories:
Amateur (consumer) products: Available to anyone without certification. Sold in garden centres, DIY stores and online. These include all the familiar brands — Roundup, Resolva, Weedol, Job Done, and similar products. They contain approved active ingredients at concentrations and in formulations deemed safe for untrained use.
Professional products: Restricted to holders of the relevant certificates. Sold through agricultural merchants and specialist suppliers who verify certification before sale. These include stronger concentrates and formulations not approved for amateur use.
The active ingredients in both categories are often identical. For example, glyphosate at 360g/L is available in both professional and consumer products. The difference lies in the formulation, surfactant package, and regulatory approval pathway rather than the core chemistry.
Getting Professional Results Without a Certificate
If your weed killer doesn’t seem to be working, the issue is almost always application technique rather than product strength. Here’s what makes the biggest difference:
- Timing: Apply when weeds are actively growing, not dormant. May-September for most species. See our when to apply guide for detailed seasonal advice
- Coverage: Thorough leaf coverage is essential for systemic herbicides. The product can only work on leaves it contacts. Don’t skimp on spray volume
- Weather: Spray on dry, calm, mild days. Rain within 6 hours washes off the product before it’s absorbed. Cold weather slows uptake dramatically
- Weed size: Smaller, actively growing weeds are far more susceptible than large, mature plants with established root reserves. Treat before weeds get out of control
- Follow-up: Allow enough time for systemic herbicides to work (7-21 days) before deciding the treatment has failed. Retreating too early wastes product
- Product choice: Use the right herbicide for the weed type. Selective lawn herbicides for lawn weeds, glyphosate for total weed clearance, fluroxypyr or triclopyr for woody growth
When to Hire a Professional
Sometimes the job genuinely calls for professional help:
For domestic gardens with typical weed problems, consumer products applied correctly are more than adequate. The strongest consumer weed killers available contain the same active ingredients as professional products. The key is matching the right product to the right weed and applying it at the right time.
Frequently Asked Questions
Is professional weed killer stronger than what I can buy in a garden centre?
Not necessarily. The active ingredient and its concentration are often identical. Professional products typically have better surfactant systems (improving absorption by 10-20%) and come in larger, more economical pack sizes. The biggest advantage professionals have is training and experience in application technique, not product strength.
Can I get a PA1/PA6 certificate for home use?
Yes, anyone can take the certification courses. However, it’s generally not worth the cost (typically several hundred pounds) and time purely for home garden use. Consumer products are perfectly effective for domestic applications. If you’re considering starting a grounds maintenance or pest control business, then certification is essential and worthwhile.
Why does my neighbour’s weed killer seem to work better than mine?
Application technique makes more difference than product choice. Common reasons for poor results include spraying in unfavourable weather, applying to dormant weeds, insufficient coverage, or not waiting long enough for systemic products to work. See our troubleshooting guide for the most common mistakes.
Can I buy professional weed killer online without a certificate?
Products labelled “professional use only” should only be sold to certificate holders. Reputable suppliers verify qualifications. Some sellers may not check, but using professional-only products without training increases the risk of harm to yourself, your garden and the environment. Consumer products are formulated to be effective and safe for untrained users.
What’s the strongest weed killer I can buy without a certificate?
Consumer glyphosate concentrate at 360g/L is widely available and is the same concentration found in many professional products. Combined with good application technique, this is effective on virtually all garden weeds. For lawn weed killers, products containing MCPA, mecoprop-P and dicamba in combination offer the broadest spectrum control.
Do I need a certificate to spray weed killer in my own garden?
No. Certification is only required for commercial pesticide application — using pesticides as part of a business or applying them on someone else’s property for payment. You are free to use any approved consumer pesticide product in your own garden without qualifications, provided you follow the label instructions.
Ready to Tackle Your Weeds?
Our weed killers range includes effective consumer-grade herbicides that deliver professional results. Proper application technique is the key to success.
