Published in the Jameson Journal, May 2026
At W.E. Jameson, we’re big believers that getting the fundamentals right delivers results, and grassland spraying is no exception. Good timing, correct conditions, and the right product choice will make the difference between a clean sward and a missed opportunity.
Why Time of Day Matters
One of the most important (and often overlooked) factors is timing within the day. Plants follow circadian rhythms, which are effectively a sleep-wake cycle. In the evening, weeds shut down; in the morning, they become active
again.
This means early morning applications, once the dew has dried, give far better results than spraying later in the day, especially with phenoxy products like MCPA and 2,4-D.
Spraying in the Right Conditions
Conditions must be right too. It is essential to always spray when weeds are actively growing above 10 °C . Avoid drought stress and disease, and avoid spraying when flowering. Also aim to treat before the sward exceeds 25 cm. Please remember – you need 4–6 hours of rain-free time for effective uptake.
Don’t Overlook Water Quality
Water quality is another key factor. Hard water can reduce the effectiveness, so adding a water conditioner can improve performance and ensure more active ingredient reaches the target.
Know Your Weeds
Understanding your weeds is half the battle. A single dock plant can produce up to 60,000 seeds, many surviving silage and even passing through livestock. Creeping thistle spreads via an extensive root system, making it harder to control. This is why early, well-timed applications are always more effective.
Product Choice – Old vs New Chemistry
From a practical W.E. Jameson point of view, our advice is straightforward: Whilst the new chemistry is good, restrictions have removed some of the most effective actives, so make the most of the older, proven chemistry whilst you still can.
For broad-spectrum control in both grazing and cutting systems, you would be hard pushed to beat Thrust® at 2.5 l/ha alongside Gal-Gone at 1 l/ha.
These phenoxy-based options remain reliable, flexible, and give the fast, visible “twist and die” effect many farmers like to see.
For bracken, with products like Asulox disappearing, there are still options available.
A practical approach includes Thrust at 2.5 l/ha with 60 g/ha Squire Ultra (EAMU-type / off-label). However, we are now seeing a shift in chemistry across the industry.
Thistlex® vs Thistlex® Pro
Take Thistlex® vs Thistlex® Pro – the new version gives with one hand and takes away with the other.
- Thistlex® Pro introduces ArylexTM, improving activity on weeds like buttercups and dandelions.
- But it loses triclopyr, meaning reduced effectiveness on tougher weeds such as nettles.
Changes to Forefront®
A similar change is happening with Forefront®.
Forefront® T (aminopyralid + triclopyr) is being phased out due to environmental concerns—it does not meet birds and mammals risk assessments.
Key dates to note:
- Sale and distribution ends 31 May 2027
- Use of existing stocks ends 30 September 2027
Going forward, the focus shifts to Forefront® Pro (aminopyralid + fluroxypyr). While this offers flexibility, it again reflects the move away from triclopyr-based chemistry.
The New Kid on the Block
One of the most exciting new products is ProClova® (Corteva), particularly as a clover-safe option. However, it comes with tighter application rules:
- Minimum 10°C for 3 days before and after application
- Best on seedling docks, not established root systems
- Slower results—around 21 days to see weeds dying back from the roots
So, if you’re after a quick visual result, phenoxies still deliver. If you’re planning longer-term control and working within tighter conditions, newer chemistry has its place.
Final Piece of Advice
Spray at the right time, spray in the right conditions, and choose the right tool for the job.
If you want fast, visible results — stick with the tried-and-trusted. If you’re adapting to changing chemistry, understand the compromises.
We’re here to help you! Call 01765 689666 for recommendations.
And if you haven’t already downloaded the 2026 Jameson Seed Catalogue, click here.
