Valdor® Flex 500g

Valdor® Flex 500g

Valdor® Flex is a residual herbicide for pre- & early post-emergence application. It controls a broad spectrum of annual and perennial broad-leaved weeds and grasses on natural surfaces not intended to bear vegetation, amenity vegetation (around) permeable surfaces overlying soil, and hard surfaces (railway ballast only). It can be applied once per year at a rate of 0.5 kg/ha.

Key Features

  • Can be used to ensure the ground around ornamental plants and trees remains weed free.
  • Ideal for use by local authorities, county councils, highways maintenance, vegetation management contractors, landscapers and many others.
  • Due to the long-lasting residual activity of Valdor® Flex, a weed free environment can be achieved alongside a reduction in the amount of herbicide applied.
Product Overview
Product Type Herbicide
Product Name Valdor® Flex
MAPP No. 19033
Active Substances Diflufenican and Iodosulfuron-methyl-sodium
Formulation Water dispersible granule
Areas of Use Amenity vegetation (around), hard surfaces (railway ballast only), natural surfaces not intended to bear vegetation, permeable surfaces overlying soil
Amateur/Professional Professional
Mode of Action Group Inhibition of pigment synthesis and Inhibition of ALS
Phytomobility Residual, Acropetal and Systemic Penetrant

Valdor® Flex - MAPP 19033

Active Substance: 360 g/kg diflufenican, 10 g/kg iodosulfuron-methyl-sodium.

Valdor® Flex should be applied pre– or early post-emergence of the plant species to be controlled. The combination of the two active substances in Valdor® Flex delivers two modes of control.

  1. Diflufenican inhibits pigment production, interrupting the plants photosynthesis ability.
  2. Iodosulfuron-methyl-sodium inhibits the enzyme, acetolactate synthase (ALS), interrupting amino acid production involved in development of normal plant growth.

The active substances in Valdor® Flex move through the plant systemically, enabling the control of young plants that are present at the time of spraying. They also provide residual activity, creating a barrier at the soil surface which is effective for up to four months. This ensure a long lasting, weed free environment.

If larger weeds are present, Valdor® Flex can be applied with glyphosate or a fatty acid to achieve control of the existing vegetation.

The Valdor® Flex Barrier
Weed Growth With the Valdor® Flex Barrier Weed Growth Without the Valdor® Flex Barrier
Weed Growth With the Valdor® Flex Barrier Weed Growth Without the Valdor® Flex Barrier

Target Species

Valdor® Flex gives pre– and early post-emergence weed control up to the two leaf stage of annual and perennial broadleaved plants and grasses. It will not control deep rooted perennial plants such as dandelion, thistle or nettles once they are established.

A selection of the plant species that are controlled by Valdor® Flex are listed below (please read the label for the full species list):

Grasses Annual Herbs Perennial Herbs Woody Plants
Annual meadow-grass (Poa annua)
Cocksfoot (Dactylis glomerata)
Bristly ox-tongue (Picris echioides)
Dove’s foot crane-bill (Geranium molle)
Common groundsel (Senecio vulgaris)
Hairy bitter cress (Cardamine hirsuta)
Knotgrass (Polygonum aviculare)
Mayweeds (Matricaria spp.)
Shepherd’s purse (Capsella bursa-pastoris)
Black medick (Medicago lupulina)
Dandelion (Taraxacum officinale)
White clover (Trifolium repens)
Greater plantain (Plantago major)
Ribwort plantain (Plantago lanceolata)
Persian speedwell (Veronica persica)
Rosebay willowherb (Chamerion angustifolium)
Yarrow (Achillea millefolium)
Cinquefoil (Potentilla fruticosa)

Instructions for Use

500 g pots come supplied with a measuring cup

Where to use:

  • For use on natural surfaces not intended to bear vegetation.
  • Amenity vegetation (around).
  • Permeable surfaces overlying soil.
  • Hard surfaces (railway ballast only).

  • When to use:

    • Can be applied year round.
    • Apply pre- or early post-emergence of weeds (up to the 2 leaf stage).
      • Where established weeds are present use glyphosate to enable control prior to application or as a tank mix.
    Valdor® Flex Application Window
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

    How to use:
    1. Add half the required water to the spray tank
    2. Add the required amount of Valdor® Flex to the spray tank
    3. Agitate the spray tank to ensure the granules are fully dispersed
    4. Top-up the spray tank with water to the required level
    Maximum Treatments Application Rate Water Volume Application Method Spray Quality
    1 per annum 0.5 kg/ha 300 - 500 L/ha Conventional hydraulic sprayer
    Vehicle mounted sprayer

    Additional Information

    • Valdor® Flex can be applied during cold weather but application to frozen ground should be avoided.
    • Do not apply to plants growing under stressful conditions as this may reduce levels of control.
    • Where Valdor® Flex has been applied to sites which are subsequently to be cleared or cultivated; a period of six months should elapse between treatment and the sowing or planting of subsequent crops AND the soil should be deeply cultivated.
    • Avoid contact with non-target plants.
    • Diflufenican will build up in the soil when Valdor® Flex or other products containing diflufenican are used in successive years.
    • For maximum efficacy ensure good coverage and do not cultivate or rake the area after application.
    • DO NOT apply over drains, or in drainage channels, gullies or similar structures for moving water.

    Active Substances


    Bio-Chemical Mode of Action: Diflufenican belongs to the inhibition of pigment synthesis group of herbicides.
    Pigment inhibitors work by interfering with pigment production, leaving the chlorophyll unprotected from sunlight. As a result, the cell contents are destroyed rapidly.

    Mobility: Diflufenican is a residual herbicide with xylem mobile activity which means that as susceptible plants come into contact with the active substance, it is absorbed through the leaves and roots then moves upwards through the plant within the xylem (water conducting tissues).

    Application timing: Pigment inhibitors should be applied pre– or early post-emergence. If applied post-emergence, they are most effective when target plants are small.


    Bio-Chemical Mode of Action: Iodosulfuron-methyl-sodium belongs to the ALS (Acetolactate Synthase) Inhibitors group of herbicides.
    Acetolactate synthase is an important enzyme involved in the biosynthesis of branched-chain amino acids. ALS inhibitors interrupt this process causing the plant to initially become chlorotic before necrosis of plant tissues followed by whole plant death occurs.

    Mobility: Iodosulfuron-methyl-sodium is a residual herbicide with xylem and phloem mobile activity which means that as susceptible plants come into contact with the active substance, it is absorbed through the leaves and roots then moves to areas of new growth within the xylem (water conducting tissues) or phloem (sugar conducting tissues).

    Application timing: ALS inhibitors are best applied when the weeds are actively growing. They are more effective when target plants are young and in their vegetative phases.

    Customer Testimonial

    Putting Valdor® Flex to the test on a heavily weeded gravel site at an international airport was a chance to find out if it would live up to expectations. Long-lasting residual control and ability to minimise resistance were two qualities we were looking for in the product, and we were very impressed by both aspects.

    Herbicide resistance is becoming a real issue in the amenity sector, so the fact the product brings new chemistry to our armoury is key. We also found it was particularly clean and easy to work with. There was no foaming in the tank, so the job was swiftly completed.

    In this trial we combined Valdor® Flex with glyphosate due to size of the weeds.

    Alan Abel

    Complete Weed Control South and Central Wales

    For further information on Valdor® Flex, please contact a member of our technical sales team on +44 (0)1902 440250.

    Delivery charge (if applicable) applied at checkout. Next working day delivery is available on this product, as an option on orders placed before 12 noon - excludes festive season & bank holidays. Please note deliveries to Highlands, Cornwall and more remote areas may take longer. Surcharges apply for non mainland locations, call for more information. More delivery info

    For large orders, please be aware that if you require a smaller 7.5 tonne lorry, the maximum weight for pallets is 750 kg - otherwise the standard pallet size limit of 1000 kg applies.

    If you have any access restrictions for lorries or large vehicles please speak to our sales team on +44 (0)1902 440250.

    Collection from our Telford, Shropshire, Trade Counter is available for this product. More info on collections