Preen Garden Weed Preventer

Write a review  

Preen Weed Preventer stops weeds from germinating in flower and vegetable gardens, in ground covers and around trees and shrubs. Preen will not kill existing weeds. It will prevent new weeds from sprouting — eliminating the need for difficult and time‑consuming hand‑weeding. Without weeds, your valuable plants can grow larger and stronger.

Your beds will stay neat and weed-free all season long!

Where to buy · View product label (PDF)

Application

How to Apply

Watch how to apply Preen Garden Weed Preventer

When plants are dry, sprinkle this product on soil surface at rate given below for your specific planting situation. Once activated by watering, it forms a weed control barrier in the top layer of soil (1 – 2 inches), preventing weed seeds from germinating. Disturbance to the soil surface after activation may result in erratic weed control.

When to Apply

Apply Preen Garden Weed Preventer during the growing season around established plants and transplants. Preen should not be used on flower seeds. It can be used after flowering plants have germinated and are 2 – 3 inches tall. Preen may also be incorporated into the soil when seeding vegetables or applied after mulching beds. By applying Preen as early as possible, you can eliminate the need for hand‑weeding.

Rain does not wash this product out of the soil. To keep beds weed‑free all season long, reapply Preen weed preventer every 9 – 12 weeks.

Applying Around Established and Transplanted Plants

For flowers, roses, herbs, ground covers, ornamental grasses, shrubs, trees, and listed vegetables at least 2 – 3 inches tall, sprinkle Preen Garden Weed Preventer evenly over the entire soil surface, at the rate of 1 oz per 10 sq ft, being sure to keep granules away from plant roots and foliage. Immediately water. If watering-in is not convenient, lightly rake into soil surface. Always wash or brush off stray weed preventer granules from plant foliage to avoid damage or discoloration.

Applying with Mulch

For best weed control, we recommend applying Preen Garden Weed Preventer after spreading mulch on your flower and shrub beds. Sprinkle Preen on top of the mulch being sure to keep granules away from plant foliage. Immediately water this product into the mulch. If watering-in is not convenient, lightly rake into top layer of mulch. Always wash or brush off stray granules from plant foliage to avoid damage or discoloration.

This is not the product label. Always read and follow directions on the product label. Use only as directed.

FAQ

Coupons

Do you offer coupons, rebates, etc?

We, as the manufacturer of Preen, do not offer any coupons or rebates. However, very often our retailers or mass merchants offer their own special sale price, coupons or rebates. Local flyers, newspaper inserts and media advertising can alert you to these offers.

General Product Questions

What is the active ingredient in Preen® Garden Weed Preventer?

1.47% Trifluralin (Treflan).

What are the other ingredients in Preen® Garden Weed Preventer?

Preen® Garden Weed Preventer also contains a carrier agent such as corn cob or attaclay.

What weed seeds does Preen® Garden Weed Preventer prevent from germinating?

See our list of weeds controlled or the product label.

How long does Preen® Garden Weed Preventer prevent weed seeds from germinating?

Up to 12 weeks per application. Reapplication may be necessary sooner if heavy rain occurs.

How long does Preen® Garden Weed Preventer stay in the soil?

Approximately 8 – 12 weeks per application. The rate at which Preen® Garden Weed Preventer biodegrades will depend on temperature, soil type, rain/moisture, sunlight and amount applied.

What weeds does Preen® Garden Weed Preventer kill?

None; Preen® Garden Weed Preventer helps to prevent its label listed weed seeds from germinating up to 12 weeks per application. It does not kill or inhibit existing weeds in any way.

What are the particles on the soil surface after I watered Preen® Garden Weed Preventer?

They are a carrier agent, such as corncob, and will biodegrade over time.

How does Preen® Garden Weed Preventer work?

Preen® Garden Weed Preventer creates a barrier that inhibits weed seed growth. The barrier lasts up to 12 weeks.

Will rain wash Preen® Garden Weed Preventer away?

No, but heavy rain may shorten its effective period.

Why is the Preen® Garden Weed Preventer container not full?

Preen® Garden Weed Preventer is packaged/sold by weight not by volume; if you weigh the container you will find that the weight is as stated or slightly higher.

I have Preen® For Gardens; Is that the same as Preen® Garden Weed Preventer?

Yes. Preen® Garden Weed Preventer is the new name for Preen® For Gardens.

Do you have a guarantee on your products?

Preen® Guarantee: To the extent consistent with applicable law, Lebanon Seaboard Corporation guarantees you will be satisfied with the performance of Preen® products when used as directed, or your money back. If not satisfied, describe the nature of your problem, and send with proof of purchase to:

Lebanon Seaboard Corporation
1600 East Cumberland St.
Lebanon, PA 17042

Proper Use

How close can I apply Preen® Garden Weed Preventer to a non-recommended plant?

Apply Preen® Garden Weed Preventer at least 12″ outside the drip-line from a non-recommended plant.

What does “established plant” mean on the Preen® Garden Weed Preventer label?

The term “established plant” refers to flowers, trees and shrubs at least 3″ in height, not recently transplanted and having a strong root system. An established groundcover is one not recently planted and that has spread or filled in to your satisfaction. (Note: Groundcovers will not spread while Preen® Garden Weed Preventer is active, about 8 – 12 weeks).

What does “non-bearing fruit and nut trees” mean?

The term “non-bearing fruit and nut trees” refers to established fruit and nut trees that are not presently bearing fruit or nuts. Preen® Garden Weed Preventer can be applied around the label listed non-bearing fruit and nut trees until they begin bearing fruit or nuts; otherwise, Preen® Garden Weed Preventer cannot be applied.

When do I apply Preen® Garden Weed Preventer?

Anytime during the growing season when the ground temperature is at least 50 – 55 degrees.

Do I have to weed first before applying Preen® Garden Weed Preventer?

Yes; Preen® Garden Weed Preventer does not kill existing weeds, so you must hand-pull existing weeds first. Note that Preen® Garden Weed Preventer will not control weeds that are tilled under.

When do I reapply Preen® Garden Weed Preventer?

Reapply every 8 – 12 weeks in the growing season.

Can Preen® Garden Weed Preventer be applied when plant foliage is wet?

No; plant injury could result.

Does Preen® Garden Weed Preventer need to be watered-in?

Yes; rain or water must immediately follow application to activate Preen® Garden Weed Preventer.

What happens if rain or water does not immediately occur after application?

Preen® Garden Weed Preventer will not start to work until rain or watering occurs. If watering is not an option, time your application with rain. Lightly rake Preen® Garden Weed Preventer into the soil surface to protect it from sunlight until rain occurs.

How much Preen® Garden Weed Preventer should I apply?

For label-recommended established flowers, shrubs, trees, and groundcovers, apply at a rate of 1 ounce per 10 square feet. For label-recommended vegetables, apply 1 pound per 640 square feet. For heavy clay or medium loam (roughly equal parts sand, silt and clay) soils, apply 1 pound per 960 square feet, and apply 1 pound per 1,280 square feet for light sandy soils.

Can Preen® Garden Weed Preventer be applied on plant foliage or plant roots?

No; plant injury could result.

What do I do if Preen® Garden Weed Preventer accidentally got on plant foliage during application?

Before watering, gently and immediately dry-brush Preen® Garden Weed Preventer off plant foliage.

How do you use Preen® Garden Weed Preventer with flowers, shrubs, and trees?

Ensure the flowers, shrubs and trees are listed on the label. Remove existing weeds and weed roots. Then, apply Preen® Garden Weed Preventer and water thoroughly.

How do you use Preen® Garden Weed Preventer with groundcovers?

Ensure your groundcovers are fully established, have spread to your satisfaction and are listed on the label. Remove existing weeds and weed roots. Then, apply Preen® Garden Weed Preventer around the dry foliage. Water thoroughly.

Do I apply Preen® Garden Weed Preventer on top of plants?

No; plant injury could result.

Why can't I apply Preen® Garden Weed Preventer to muck soil or soils containing more than 10% organic matter?

These types of soils will neutralize the active ingredient in Preen® Garden Weed Preventer.

When do I apply Preen® Garden Weed Preventer with bulbs?

Apply on dry, weed-free garden soil when any of the label-recommended bulb plants are at least 3″ tall. Water immediately after application.

Does Preen® Garden Weed Preventer control weeds that are tilled under?

No; weeds that are not completely removed will emerge again.

Do I apply Preen® Garden Weed Preventer by hand?

No; apply with either the refillable shaker canister, the scoop included in some Preen® Garden Weed Preventer packaging, your garden scoop, or a make shift applicator.

Can I mix Preen® Garden Weed Preventer with water before application?

No; mixing with water dilutes the active ingredient and renders Preen® Garden Weed Preventer ineffective.

How long after an application of Preen® Garden Weed Preventer should I wait before planting non label-recommended plants?

Wait 12 weeks from when Preen® Garden Weed Preventer was applied.

Staining

Can Preen® Garden Weed Preventer stain?

Yes; Preen® Garden Weed Preventer can stain porous surfaces such as concrete, rocks, bricks, landscape blocks, shoes, leather and linoleum.

How do I prevent possible staining?

Before watering Preen® Garden Weed Preventer, dry brush stray granules off non-target surfaces. Store Preen® Garden Weed Preventer packages in a garage or shed on top of cardboard or newspaper.

How can I get rid of a Preen® Garden Weed Preventer stain?

Try Goo Gone or another citrus-based cleaning product to lessen the appearance of or remove a stain. Always test a small area first to ensure the product won't cause additional staining.

For porous surfaces: Use equal parts soapy water and bleach, or a paste of baking soda and water, or ultraviolet light/sunlight, or a citrus-based cleaner, or 409 carpet foaming spray cleaner. Always follow manufacturer's directions.

For non-porous, uncoated surfaces: Use acetone or an acetone based nail polish remover.

Storage & Safety

Where can I find emergency medical information for Preen® Garden Weed Preventer?

Immediately call Prosar Corporation toll-free at (888) 208-1368 and/or 911.

When can people and pets enter an area that was treated with Preen® Garden Weed Preventer?

They may enter the treated area after it is thoroughly dry from the first rain and/or watering.

Can I walk on a Preen® Garden Weed Preventer treated area?

Avoid walking on a treated area; any disturbance will result in erratic weed prevention.

How do I dispose of Preen® Garden Weed Preventer or its empty container?

Call your local municipality to inquire on proper product disposal and/or package recycling, or call 1-800-CLEANUP. If not recyclable and container is empty, place empty container in trash.

Does Preen® Garden Weed Preventer expire?

No; Preen® Garden Weed Preventer has an indefinite shelf-life as long as it's sheltered from moisture and sunlight.

Can Preen® Garden Weed Preventer be stored for next year?

Yes. Store in a dry place away from sunlight and moisture, atop a piece of cardboard or an old newspaper.

What can I do if I applied Preen® Garden Weed Preventer to my lawn, grass or flower seeds, a non-recommended plant, etc.?

The active ingredient should be neutralized using activated charcoal granules. Activated charcoal can be found at garden centers, pool supply stores, pet stores, or in the aquarium supply section of stores. Call the store first to confirm availability. Charcoal bricks used in a grill will not work.

  1. Sprinkle activated charcoal granules onto the soil surface at a rate of one pound per 100 square feet.
  2. Gently rake the activated charcoal into surface of soil.
  3. Thoroughly water the activated charcoal treated area.
  4. Repeat the watering schedule for three days.
  5. Cease watering and wait two days. After two days, the active ingredient in the product will be neutralized
Preen® Garden Weed Preventer was over-applied in my garden. Is there any risk?

Yes; injury may occur to plants.

Preen® Garden Weed Preventer was over-applied in my garden. How can I save my plants from injury?

If rain or watering did not occur: Physically remove Preen® Garden Weed Preventer.

If rain or watering did occur, or if you were unable to physically remove Preen® Garden Weed Preventer, neutralize Preen® Garden Weed Preventer following these steps:

The active ingredient should be neutralized using activated charcoal granules. Activated charcoal can be found at garden centers, pool supply stores, pet stores, or in the aquarium supply section of stores. Call the store first to confirm availability. Charcoal bricks used in a grill will not work.

  1. Sprinkle activated charcoal granules onto the soil surface at a rate of one pound per 100 square feet.
  2. Gently rake the activated charcoal into surface of soil.
  3. Thoroughly water the activated charcoal treated area.
  4. Repeat the watering schedule for three days.
  5. Cease watering and wait two days. After two days, the active ingredient in the product will be neutralized

Use Around Seeds and Young Plants

Will flower seeds germinate with Preen® Garden Weed Preventer?

Flower seeds will not germinate or reseed while Preen® Garden Weed Preventer is active (about 12 weeks per application).

How long after an application of Preen® Garden Weed Preventer should I wait before planting new seed or transplanting?

Wait 12 weeks from when Preen® Garden Weed Preventer was applied.

How do I apply Preen® Garden Weed Preventer with vegetables?

Ensure the vegetable plants are listed on the label. Remove existing weeds and weed roots. Then, apply Preen® Garden Weed Preventer and water thoroughly.

Use with Mulch

Can Preen® Garden Weed Preventer be applied on top of mulch?

Yes. After removing existing weeds and weed roots, rake the mulch to loosen it, and ensure the mulch is 2 – 3 ″ thick. Then, apply Preen® Garden Weed Preventer and water thoroughly.

Can I apply Preen® Garden Weed Preventer before mulching?

Yes, after removing existing weeds and weed roots. Then, apply Preen® Garden Weed Preventer and water thoroughly.

Where to Apply Preen

Can Preen® Garden Weed Preventer be applied around corn?

No; Preen® Garden Weed Preventer is not labeled for use on corn.

Can Preen® Garden Weed Preventer be applied to strawberries?

No; Preen® Garden Weed Preventer is not labeled for use on strawberries.

Can I use Preen® Garden Weed Preventer on my lawn or with grass seed or sod?

No; turf injury could result. Preen® Garden Weed Preventer is not labeled for use on lawns.

Can I use Preen® Garden Weed Preventer in or near a pond, lake, or other type of waterway?

No; Preen® Garden Weed Preventer is harmful to aquatic life.

Can I use Preen® Garden Weed Preventer around, under, or near a swimming pool, sandbox, playground type areas, or under bird feeders?

No.

Can I use Preen® Garden Weed Preventer in or near a greenhouse or any type of enclosed area?

No; staining and/or volitization could occur causing plant injury.

Can I use Preen® Garden Weed Preventer where chickens, horses or other animals graze?

No.

Can I use Preen® Garden Weed Preventer on a garden slope or hillside?

Yes, if a waterway is not at the bottom of the slope or hillside.

Can Preen® Garden Weed Preventer be used in potted plants or planter boxes?

No; plant injury could result.

Can I apply between bricks or patio blocks, on pebbles or on other hard surfaces?

No; Preen® Garden Weed Preventer will stain porous surfaces such as brick, patio blocks, stones, etc.

What plants are recommended with Preen® Garden Weed Preventer?

See our plant compatibility tool or the product label.

Can I use Preen® Garden Weed Preventer with a plant that is not listed in the recommended established plant section?

Yes, but use caution. Make a trial application of Preen® at the recommended rate around one or two plants. Observe the plants for 30 to 60 days. If plant injury results, do not use Preen® around other plants of the same species. [NOTE: Consumer assumes liability for any plant damage resulting from the use of Preen® around plant species not recommended on the label.]

Where to Buy Preen

Is Preen® Garden Weed Preventer available outside of the United States?

No; Preen® Garden Weed Preventer is not available or registered outside of the United States.

Can I order Preen® Garden Weed Preventer on your website?

No, but the product is available at most home and garden centers. Use our store locator to find a retailer near you.

Available Sizes

To review a particular product within this family please choose from one of the available sizes below, or you may continue to write a review for Preen Garden Weed Preventer without selecting a size.

Product Support

The PDF documents on this page may require the Adobe Reader to be viewed.
Get Acrobat Reader web logo