Specticle FLO is a selective, preemergence herbicide containing the active ingredient indaziflam. It’s formulated to provide long-lasting control of various grassy and broadleaf weeds in landscape beds.

Specticle FLO effectively manages a vast variety of weeds that are germinating from seeds, including:

• Crabgrass
• Goosegrass
• Annual bluegrass (Poa annua)
• Annual sedges
• Over 60 broadleaf weeds germinating from seed

For a comprehensive list, refer to the product label.

No, Specticle® FLO is primarily a preemergence herbicide, meaning it prevents the germination of annual weeds, but it does not harm established perennial weeds, grasses, trees, bulbs, or shrubs.

Targets Seed Germination

It works by inhibiting cell division in germinating seeds, making it effective against annual weeds that reproduce from seed.

Perennials Have Established Root Systems

Perennial weeds regrow from established roots, rhizomes, or stolons, which Specticle FLO does not target.

Lacks Postemergence Activity

Specticle FLO does not kill actively growing weeds; it only prevents new ones from emerging.

Specticle® FLO has extremely low leaching potential.

Low Water Solubility & Strong Soil Binding

• The active ingredient in Specticle FLO, indaziflam, has low water solubility and binds tightly to soil particles.
• This strong binding helps prevent leaching and keeps the herbicide in the upper soil layer where it can target weed seeds.

Factors That Could Influence Leaching

• Soil Type – Sandy or low-organic-matter soils may have a slightly higher risk of leaching compared to clay or organic-rich soils.  Fortunately in Colorado we have heavy clay soils so leaching is virtually non-existent. 

Organo-Lawn will not apply anything -organic nor synthetic – to a vegetable garden.

Specticle® FLO can be considered extremely low-toxic for dogs and pets when applied correctly and allowed to dry completely before pets re-enter the treated area.

Safety Considerations for Dogs & Pets

• Extremely Low Toxicity When Dry: Once dried, Specticle FLO has minimal to no risk to dogs and other pets.
• Harmful if Ingested: If a pet licks, eats, or comes into direct contact with the wet product, it may cause gastrointestinal upset or mild irritation.
• Mild Skin & Eye Irritation: If pets walk through wet treated areas, it could lead to skin irritation or eye discomfort if they rub their paws on their face.

Precautions for Pet Owners

• Keep Pets Off the Lawn Until Dry: Wait until the product has dried and for extremely cautious pet owners wait 24 hours before allowing pets back on the lawn.
• Clean Paws if Necessary: If your pet walks through a wet application, rinse their paws with water and monitor for irritation.

What to Do If a Pet Comes into Direct Exposure (According to the Label)

• Skin Contact: Wash with mild soap and water.
• Ingestion: Provide water and monitor for vomiting or diarrhea. Contact a vet if symptoms persist.
• Eye Exposure: Rinse eyes with clean water and seek veterinary care if irritation continues.

Specticle® FLO provides long-lasting preemergence weed control, with effectiveness lasting up to 8 – 12 months, depending on factors like application rate, soil type, and environmental conditions.

Duration of Weed Prevention

• Typical Control Period: 8 -12 months
• Higher Rates: Can extend control closer to 12 months in ideal conditions.
• Lower Rates: May provide closer to 4-6 months of control, but we don’t have these conditions in Colorado.

Factors Affecting Longevity

• Soil Type:
  • Sandy soils may reduce longevity due to higher leaching potential.
  • Clay or organic-rich soils like we have in Colorado retain the herbicide longer.
  • Microbial activity – the product is disrupted by increased microbial activity in the soils.  During the winter months microbial activity is almost zero so Colorado winters do not affect the longevity of this product.
• Rainfall & Irrigation:
  • Excessive rainfall or over-irrigation can reduce effectiveness.

Recommended Application Frequency

• One application per season is sufficient in Colorado, especially when applied during the winter months.

The guarantee for weed control for the season long pre-emergent depends on a number of factors. 

A Few Weeds vs a Lot of Weeds

A few weeds are normal.  A few means hand pulling a weed here and there once or twice a month.  A lot of weeds is not normal.  

For First Time Applications or a Lapse in Yearly Applications

If this is the first time the application is being performed, or if there has been a gap between yearly treatments, weed prevention is not fully guaranteed. This is because the pre-emergent herbicide does not stop perennial weeds from germinating, as they regrow from established root systems rather than seeds. To effectively manage these persistent weeds, a post-emergent herbicide application is necessary.

We recommend budgeting for one or two post-emergent treatments to target and eliminate perennial weeds, ensuring a more comprehensive weed control strategy—especially after the first pre-emergent application.

For Customers with Yearly Applications

November, December, January, and Early February Applications: If the application was performed during the recommended months, weed control is guaranteed. While we cannot promise 100% prevention—as a few weed species may not be fully controlled—our treatment is designed to provide effective, long-lasting suppression. However, if an abnormally high number of weeds emerge despite proper application, we will stand by our guarantee and ensure the treatment is effective.

Late February, March and Early April Applications:  If the application was performed during these months, we cannot guarantee full weed control, as many weeds may have already germinated. However, a March or April treatment still provides significant value, as it helps prevent a large number of weeds from emerging. That said, some weeds begin germinating as early as late February, making it challenging to achieve complete prevention with a later application.

Warmer Temperatures

November is typically the ideal month for applying the pre-emergent weed control in landscape beds. During this time, temperatures are usually warm enough for liquid applications to be applied without risking our spray tanks to freezing temperatures. Additionally, snow accumulation—especially on north-facing areas—can make treatments difficult to apply later in the season.

Available Workforce

Another key advantage of a November application is workforce availability. The majority of our seasonal team is still on hand to perform applications efficiently. However, after Thanksgiving, finding a suitable weather window becomes increasingly challenging. Cold temperatures, snow-covered ground, and limited staff availability make it difficult to complete applications at the same level of quality and effectiveness.

Moisture is Required Post Application to Activate

Finally, Specticle FLO requires moisture to activate its weed control properties. The source—whether rain, snow, or irrigation—does not matter. November applications provide ample time for natural precipitation to occur before weed seeds germinate, ensuring optimal effectiveness.

Yes, Specticle® FLO can temporarily stick to fallen tree leaves if applied to a landscape bed, but it won’t stay attached to a tree leave like it attaches to the soil.

Does Specticle FLO Adhere to Fallen Leaves?

• Yes, it can temporarily adhere to fallen leaves, especially those with textured or waxy surfaces.
• Because it is a liquid pre-emergent, some of the herbicide may coat the leaves rather than reaching the soil, where it needs to be for effective weed prevention.
• Over time, rain, irrigation, or natural decomposition will wash it off, allowing the herbicide to reach the soil.

Will Specticle FLO Still Work If It Lands on Leaves?

• Reduced effectiveness if too much product remains on leaves instead of reaching the soil.  Our technicians are trained on what is an acceptable amount of tree leaves vs what is too many. 
• Leaves can act as a barrier, preventing the herbicide from properly binding to the soil and creating the necessary pre-emergent barrier.  A few leaves are not a problem, a lot of leaves should be cleaned up prior to the application.

Best Practices for Application in Landscape Beds with Fallen Leaves

• Remove excess leaves before applying to ensure better soil contact.
• If leaf removal is not possible, apply before rain or irrigation to help wash the product off of the tree leaves and into the soil.
• Avoid applying over thick leaf layers, as the product may break down or degrade before reaching the soil.
• If necessary, consider a light raking or gentle watering after application to help move the herbicide off the leaves and onto the soil.

There are limited application windows due to weather related issues during certain months of the year, making it significantly more challenging to complete treatments at other times. However, the effectiveness and longevity of the product remain unchanged, as its breakdown is primarily influenced by microbial activity.

During the winter months in Colorado, microbial activity is virtually inactive, meaning a November application lasts just as long as an April application. Since the product only degrades in the presence of active microbes, applying it in colder months does not compromise its effectiveness or duration.

November

This period typically provides the ideal weather window for our applications. Daytime temperatures hover in the 50s, ensuring optimal conditions for effective treatment. Additionally, longer daylight hours allow for more efficient scheduling, and we still have the majority of our seasonal workforce available, ensuring timely and thorough applications.

December, January, February

The weather during this time is often too cold, too windy, or impacted by un-melted snow, especially on north-facing areas of properties. Logistically, we may only have 3-4 suitable days per month to apply the product without significant interference from Mother Nature, making it a challenging window for consistent applications.

March and Early April

These months are typically our snowiest of the year, making it a constant challenge to work around unpredictable weather conditions. Additionally, our employee availability is limited during this time, as our team is focused on spring aerations and Spring Synergy applications, further restricting our ability to complete treatments efficiently.

Specticle FLO is generally more effective in rock beds due to better soil contact and less organic material breakdown. In mulch beds, its effectiveness can be reduced by about 20%, but compared to other pre-emergent weed controls the effectiveness of Specticle FLO in mulch beds is remarkably high.

• In rock beds, the herbicide reaches the soil more efficiently, where it creates a long-lasting pre-emergent barrier.
• In mulch beds, the product may bind to organic material in the mulch, reducing its ability to reach the soil and shortening its longevity due to microbial breakdown.

Yes, Specticle FLO is labeled for use in both residential and commercial ornamental landscapes, including rock and mulch beds.

• Longer residual control than many competitors (8-12 months in rock, 6-10 months in mulch).
• More effective against broadleaf and grassy weeds compared to some traditional pre-emergents.
• Better stability in rock beds and won’t leach from soils even with heavy rain.

Specticle FLO is a pre-emergent herbicide that requires watering to activate its active ingredient and bond with soil particles. After application, irrigate the treated area with 0.125 to 0.25 inches of water within 31 days, ensuring this occurs before weed seeds germinate. This light moisture helps move the herbicide into the soil, maximizing its effectiveness.

The source of moisture—whether from rain, snow, or irrigation—does not matter. If rain occurs immediately after application, it provides ideal activation for optimal weed control. However, successful weed prevention has also been observed even when no precipitation occurred for up to 60 days post-application.