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Inhibitor 18-0-6 for
Pre-emergent Weed Control of Annual Weeds*

Inhibitor 18-0-6 for
Pre-emergent Weed Control of Annual Weeds*

Order Information

Available Online Only
Item Number: 18006
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Product Description

Attack the seeds before they become weeds.

*Not for sale in the State of WA.

  • Treats 5,000 square feet when applied at 4 pounds per 1,000 square feet.
  • Inhibitor 18-0-6 is a granular fertilizer with Prodiamine, a synthetic crabgrass reducer.
  • Use this product with established turf grass, and never use it on newly seeded lawns.
  • Read instructions carefully before applying for application methods and rates.
  • Apply at the recommended rates only.
  • Do not apply near water, storm drains, drainage ditches or if heavy rain is in the forecast.
  • Sweep excess product from driveway, sidewalk or street back onto the lawn.
  • Click here for label information

Product Details

When to Apply

Successful pre-emergence control of the annual grass weeds listed on this label requires proper timing of application. Apply this product 1 to 2 weeks prior to the germination of annual grass weeds. If application timing does not coincide with the normal germination period of any of the annual grass weeds listed on this label, weed control results may be erratic or poor. (Weed seeds typically begin to germinate when soil temperatures reach 55 degrees Fahrenheit.)

Weeds controlled when applied prior to weed germination:

Annual Grasses:

  • Annual Bluegrass
  • Barnyardgrass
  • Crabgrass (large, smooth)
  • Goosegrass
  • Crawfootgrass
  • Foxtails, annual

Broadleaf Weeds:

  • Chickweed, common
  • Knotweed
  • Lambsquarters, common
  • Pigweed
  • Purslane, common

In areas where germination of the annual weed grass species continues for an extended period of time, make a second application at the recommended rate 8 to 10 weeks after the first application on cool season turfgrass and 10 to 12 weeks after the first application on warm season turfgrass.


Optimum weed control performance will be obtained if treated areas receive rainfall or irrigation soon after application.

General Use Precautions and Restrictions:

  • Do not apply this product to golf course putting greens.
  • Do not apply this product through any type of irrigation system.
  • Any cultural practices that disturb the soil, such as aeration or verticutting, should be done prior to application of this product.
  • Do not apply to overseeded turf within 60 days after seeding or until after the second mowing.

This product is recommended for use on the following turfgrass species:

Established Cool Season Turfgrasses:

  • Creeping bentgrass
  • Kentucky bluegrass
  • Fescues
  • Perennial ryegrass

Established Warm Season Turfgrasses:

  • Bahiagrass
  • Fescue, tall
  • Bermudagrass
  • St. Augustinegrass
  • Centipedegrass
  • Zoysia

How to Apply:

Apply this product evenly over the turfgrass area using a properly calibrated drop type or rotary spreader. Calibrate the spreader prior to use according to the manufacturer's directions. Check frequently to make sure equipment is working properly and distributing granules uniformly. More uniform application may be achieved by spreading half of the required amount of product over the area and then applying the remaining half in swaths at a right angle to the first. Avoid skips and excessive overlaps as poor weed control or turfgrass injury may occur. Avoid use of spreaders that apply material in narrow concentrated bands. A splashboard mounted below the release point of drop-type spreaders can improve the uniformity of product distribution.


Established Turfgrass

Broadcast Application Rates:

Application Time Cool Season Turfgrass Warm Season Turfgrass
Spring Application 4-6lb/1,000 square feet 8lb/1,000 square feet
Fall Application 4-8lb/1,000 square feet 8lb/1,000 square feet

This product may also be applied in single applications or split applications. For Maryland and states south, apply 2 applications at 4 lbs per 1,000 sq. ft 8-10 weeks apart. For states north of MD apply 6 lbs of product per 1,000 sq. feet prior to crabgrass germinating. This program is desirable when the initial application is made well in advance of weed germination and where weed control is desired for a longer period of time.

Specific Use Restrictions:

  • Do not make more than 2 applications totalling 11 pounds of this product per year on turfgrass.
  • Maximum single application rate: 8 pounds per 1,000 square feet.
  • Minimum Re-treatment Interval: Cool season turf – 56 to 70 days; warm season turf – 70 to 84 days.
  • This product must be watered in as soon as possible after application.


Do not reseed treated areas for at least 4 months after a single application of 4 pounds per 1,000 square feet of product unless injury can be tolerated.

Reseeding Precautions:

Prodiamine, which controls annual grass weeds, may also affect the establishment of new desirable turfgrass seedlings, if reseeding is attempted too soon after application. When reseeding, it is essential that proper cultural practices, such as soil cultivation, irrigation and fertilization be followed. Reseeding, following the last application of this product, should not be attempted until the applicable minimum time delay in the following table has been met or less than desirable results may happen.

Amount of Product Applied Per   
1,000 Square Feet (SF)
Minimum Time Delay Following Last
Application Before Reseeding (Months)
Single application of 4 lbs/1,000 sf 4
Single application of 8 lbs/1,000 sf 6
Split application of 4 lbs/1,000 sf 4 to 5
Split application of 8 lbs/1,000 sf 5 to 6
Norman Linnell
Is Inhibitor 18-0-6 pet-safe ?
4/23/2016 10:47:37 AM

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Do I have to water this product after I apply it?
Yes, water activates the ingredients for a more effective outcome.

How do I know my spreader setting?
Call us at 888-546-5941 with your spreader model, and we will help you find your spreader setting. Or, click here for a list of spreader settings.

How long should I wait between the time I apply Inhibitor® and the time I apply my Natural Alternative Early Spring Application?
We recommend waiting six weeks between applying the two products.

Is this product organic?
No, this product has an organic-based fertilizer; however, the pre-emergent weed control is a synthetic ingredient known as Team Pro®. Learn more about this product.

The weeds are already up. Should I still apply this product?
If the seeds have germinated and have turned into weed plants, this product will not be as effective. We recommend waiting until the next fall or spring (whichever season comes next for you) and use the product at the recommended rates.

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