--- title: BROCHURE - Syngenta Barricade for Nursery Use canonical: https://fernland.com.au/documents/876/ dateModified: 2026-07-12 07:55:19 summary: Technical Sheet type: tech_sheet --- # BROCHURE - Syngenta Barricade for Nursery Use > Technical Sheet BARRICADE Herbicide is a GROUP D pre-emergent herbicide that has a great fit in nurseries and landscape settings for controlling weeds in potted plants and garden beds. Attention needs to be paid to the application of BARRICADE in order to optimise the weed control in nursery potted plants. The diversity of plant types, canopy shapes, pot sizes and soil types all need to be considered along with the limitations of application equipment. **Plant foliage** One of the greatest physical barriers is the plant foliage itself – you need to either go around it or through it, or both, to get adequate soil coverage. The application method you use may have limitations depending on whether the pots are blocked or spaced and the size of the plant relative to the pot size. Post-application wash-in also needs to be considered depending on the barrier the foliar canopy presents. | Multi-nozzle boom – ‘over the top’ | Single nozzle/wand – ‘directed spray’ | | :--- | :--- | | Best for smaller plants, tightly blocked | Best for bigger plants, wider spacing or difficult access | *** [Diagram: Two scenarios showing application methods] **Foliar canopy similar size to pot diameter, loosely spaced plants** [Diagram: Three pots with plants. A boom sprayer is overhead. Arrows indicate "Wastage" between pots. Text: "Poor coverage of soil due to foliar shielding."] [Diagram: A single pot with a plant. A wand sprayer is applying a direct spray. Text: "Direct spray with single nozzle is a better option. Targeted delivery is achieved and a very light post-application irrigation is required."] **Foliar canopy smaller in size to pot diameter, plants closely spaced** [Diagram: Five pots with plants. A boom sprayer is overhead. Text: "Less wastage but there is still potentially a physical barrier from foliage. Attention to post-application irrigation is critical."] *** **Root development** It is important that the plants, especially when they have smaller canopies have sufficiently developed root systems when using BARRICADE. An assessment of this is vitally important and should be conducted before product use. Applying BARRICADE to young plugs, cuttings or divisions whose roots are young, poorly developed or very shallow can compromise their safety. It is important that BARRICADE is not applied to plants that have under developed root systems where a large percentage of the total available root mass sits within the BARRICADE band (see illustrations overleaf). As a GROUP D herbicide, BARRICADE works by inhibiting the root tips of germinating weeds. A weed may germinate but quickly has its root development impeded and eventually completely halted. Weed seeds will usually germinate right at the top of the soil in the pot and that is where BARRICADE needs to be placed. It naturally likes to stay very high in the soil, and this keeps it away from the roots of the plant we are trying to grow. *** **Root system – size and development** [Diagram: Three pots showing different stages of root development] * [X] Transplanted struck cutting * [!] Early establishment * [✓] Root system filling the pot – more developed **NOTE:** The BARRICADE label states plant development must be assessed when considering use and recommends a period of growth and establishment occurs before first application. “**DO NOT** apply to recently re-potted or newly potted cuttings, divisions or plants. Allow a period of establishment within which a substantial root system can be developed.” [Legend: X Not recommended, ! Care should be taken, ✓ Safe] [Label: Where BARRICADE sits in the soil] *** The importance of root size and position as it relates to overall plant age and development needs to be considered when applying BARRICADE. In addition, the influence that the media type will play on where BARRICADE positions and performs also needs to be overlayed. **Potting media** The active ingredient in BARRICADE (prodiamine) has an inherent desire to bind to soil and organic matter. This is a very good thing as it allows the product to stay where it has been placed during the application process and not leach out or move unpredictably. Even though these are very strong characteristics of BARRICADE, as we move between potting media there will be subtle differences in the final locations achieved post-application. There are some media that are simply not suitable for BARRICADE use as the pore sizes are too large and the ability to form a weed control barrier is just too limited. Examples are pure bark chips and extremely coarse media used for epiphytes, orchids and sometimes other tropical species such as Bromeliads. For these species, perfect drainage is essential and the movement of moisture away from root systems is imperative so BARRICADE use will not be an option. *** **Heavier soils with higher organic content** In potting media that are heavier or have a high organic component throughout, BARRICADE will stay in a thinner more defined band and will position higher. [Diagram: Pot with a thin blue band at the top. Label: "Narrow band"] **Sandier soils or media containing more inorganic components** In media that have a greater amount of loose inorganic components and sands, ie a lesser amount of potential binding components, the BARRICADE band will likely be wider. [Diagram: Pot with a thick blue band at the top. Label: "Wider band"] *** BARRICADE positions near the soil surface and in different media displays subtle differences. How BARRICADE is applied also needs to be considered and here we identify some tips for application and post-application irrigation so as to avoid unnecessary troubles. **Application and post-application irrigation (product placement)** 1. Use appropriate nozzles such as air induction 08 Nozzles. These nozzles will deliver droplets that are in the coarse or extra coarse spectrum minimising drift and maximising product hitting its target. These big droplets also help any liquid landing on foliage to run off and start making its way to the soil. 2. Light post-application irrigation ensures product is washed off the foliage and moved into the top couple of centimetres of the media providing the opportunity to bind and establish the weed control band. *** When the right combination of application and post-application wash-in is used, a solid weed control band is produced and product performance is more likely. If, however, you were to get excessive with the wash-in (too high a volume), or high rainfall occurred in the 24-48 hours after application, there is a risk that the active ingredient may not be sufficiently bound and might be forced deeper into the pot where root damage is possible. [Diagram: Two pots] * Left: "Good application and light post-application irrigation. BARRICADE positions near the soil surface." * Right: "Poor application and excessive post-application irrigation or rainfall. BARRICADE moves lower into the pot." [Diagram: Three pots with dense foliage. Text: "Denser foliage, more wash-in required. Obstruction to spray delivery, post-application wash-in is important."] *** BARRICADE Herbicide is now registered for pre-emergent control of weeds in garden beds and nursery pots. | Situation | Weeds | Rate | | :--- | :--- | :--- | | Garden beds (under mulch) and potted plants in nurseries, public open spaces and residential or commercial gardens | Nursery weeds such as: African Lovegrass (Eragrostis curvula), Barnyard Grass (Echinocloa crus-galli), Chickweed (Ceratium glomeratum), Crab Grass (Digitaria sanguinalis), Crowsfoot Grass (Eleusine indica), Creeping Oxalis (Oxalis corniculata), Cudweed (Gnaphalium spp), Paspalum (Paspalum dilatatum), Prairie Grass (Bromus wildenowie), Rat’s Tail Fescue (Vulpia myuros), Ryegrass (Lolium perenne), Sow Thistle (Sonchus spp), Summer Grass (Digitaria ciliaris), Willowherb (Epilobium ciliatum), Winter Grass (Poa annua) | 4 to 8 L/ha | Refer to the registered label for full details and instructions for use. *** **What BARRICADE offers you:** * A liquid formulation for ease of use and accurate dosing * A herbicide exempt from poison scheduling providing good worker safety during and following use * Long lasting control – up to 4 months in potted plants and 6 months in garden beds under mulch * A great option for use across a range of plants including species normally sensitive to spreadable granule formulations [Image: Bottle of Barricade Herbicide and photos of nursery plants]