Preen Mulch Plus

Preen Mulch Plus is rated 3.5 out of 5 by 187.
  • y_2017, m_7, d_25, h_7
  • bvseo_bulk, prod_bvrr, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_187
  • loc_en_US, sid_PRODUCT0013, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_preen
  • bvseo_sdk, net_sdk,
  • getAggregateRating, method:CLOUD, 266ms

Available at Lowe's and independent garden centers nationwide!

Preen Mulch Plus is a premium quality garden mulch combined with two long-lasting pre-emergence herbicides. One application of Preen Mulch provides 6 months’ control of broadleaf weeds and annual grasses in flower and ornamental beds. Plus, it helps landscaped areas retain moisture – protecting your plants, trees, and shrubs from extreme temperatures.

To view the available colors, including Russet Red, Chestnut Brown, and Midnight Black, please click on the Available Sizes tab below.

Plant Check
Quick Links


How to Apply

Bulbs and Perennials: Spread Preen Mulch Plus over the area to a depth of two inches. Do not plant flowers directly into garden mulch. If additional planting is desired after Preen Mulch has been applied, first remove the mulch from the selected area. Avoid getting treated garden mulch into the planting hole. Once the plant is firmly embedded in the soil, replace the mulch around the plant.

Annuals: After plants have been set in the soil bed, spread Preen Mulch Plus over the area to a depth of two inches. Make no more than one application per site per year.

When to Apply

Preen Mulch Plus contains pre-emergent herbicides and for best results, remove all weeds in the beds prior to applying the garden mulch. You may apply anytime in the spring and fall after renovating beds, but for best results, apply Preen Mulch Plus after flowers and ornamentals have been planted into the soil. Do not apply over flower seeds.

For ornamental bulbs, apply 2 to 4 weeks after planting, or before or after flowering. Do not apply to bulbs when flowering.

How Much Mulch Do You Need?

Although most mulches temporarily suppress weeds when applied at a minimum depth of 3 inches, only Preen Mulch Plus, with its weed barrier technology, blocks weeds for up to 6 months when applied 2 inches deep.

When applied according to label directions, one 2 cu. ft. bag of Preen Mulch Plus covers 12 sq. ft. at 2 inches deep. Other brands recommend 2 cu. ft. bags be applied at 3 inches deep, which will cover 8 sq. ft. With Preen Mulch Plus, you'll use fewer bags to cover more space than other brands and get much better weed control.

Enter your garden size to calculate the number of 2 cu. ft. bags of mulch needed.

Length ft inches
Width ft inches


Preen Mulch Plus number of 2 cu. ft. bags needed     
Other brands number of 2 cu. ft. bags needed *  

(* Other brands recommend applying their mulch at 3 inches deep.)



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® Mulch Plus®?

0.0032% Trifluralin (Treflan) and 0.0008% Isoxaben (Gallery); excludes New York. ( In New York only, 0.0032% Trifluralin (Treflan)).

What are the other ingredients in Preen® Mulch Plus®?

They are premium natural forest hardwoods and a dye colorant. Preen® Mulch Plus® contains no recycled wood materials.

Is Preen® Mulch Plus® single, double, or triple shredded?

Double shredded.

What weed seeds does Preen Preen® Mulch Plus® prevent from germinating?

See our list of weeds controlled or the product label.

How long does Preen® Mulch Plus® prevent its label listed weed seeds from germinating and/or last in the soil?

Up to 6 months per application, excluding New York. In New York only, up to 4 months per application. The rate at which Preen® Mulch Plus® biodegrades will depend on temperature, soil type, rain/moisture, sunlight and amount applied.

What weeds does Preen® Mulch Plus® kill?

None; Preen® Mulch Plus® helps to prevent its respective label listed weed seeds from germinating. It does not do a thing to existing weeds, their underground root/runner system, etc.

What does “established plant” mean on the Preen Preen® Mulch Plus® 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® Mulch Plus® is active, about 4–6 months).

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

Plants that will not bear fruit for at least one year after treatment of Preen® Mulch Plus®.

How does Preen® Mulch Plus® work?

Preen Preen® Mulch Plus® creates a barrier that inhibits weed seed growth. The barrier lasts up to 4 weeks in New York, or up to 6 weeks in states other than New York.

Does Preen® Mulch Plus® Cocoa Brown contain cocoa, cocoa shells, chocolate, or theobromine?

No; “cocoa brown” simply describes the color of the mulch.

What is the bag weight of Preen® Mulch Plus®?

The approximate bag weight is 30 pounds. Preen® Mulch Plus® is packaged/sold by volume, not by weight. Some settling may occur during shipment. Net content is 2 cubic feet with a coverage of 12 square feet, as validated by the Mulch and Soil Council.

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

When do I apply Preen® Mulch Plus®?

Anytime in the growing season when the ground temperature is at least 50–55 degrees, and after listed flowers and ornamentals have been planted into the soil. For ornamental bulbs: Apply 2 – 4 weeks after planting, or before or after flowering. Do not apply to bulbs when flowering.

Do I have to weed first before applying Preen Preen® Mulch Plus®?

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

When do I reapply Preen® Mulch Plus®?

Reapply every 6 months, except in New York. Reapply every 4 months in New York only. However, make no more than one application per site per year for listed annuals.

When can Preen® Mulch Plus® be put in a compost pile?

After 6 months (excludes New York), or after 4 months in New York only. However, it is recommended to keep it out of the compost process and let it break down naturally in the landscape bed.

Do I water Preen® Mulch Plus® after application?


Can I walk on a Preen® Mulch Plus® treated area?

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

How much Preen® Mulch Plus® do I apply?

Apply to a depth of two inches.

Can I plant plants directly into Preen® Mulch Plus®?


Can Preen® Mulch Plus® be applied to plant roots or, wet or dry plant foliage?

No; plant injury could result. Immediately dry-brush Preen® Mulch Plus® gently off plant foliage.

How do you use Preen® Mulch Plus® with established bulbs and perennials?

Remove existing weeds, and apply Preen® Mulch Plus® around listed bulbs and perennials.

How do I plant label recommended bulbs and perennials in an area that was already treated with Preen® Mulch Plus®?

First, remove Preen® Mulch Plus® from the selected area. Avoid getting treated mulch and soil in the planting hole. Once the plant is firmly embedded in the soil, replace the mulch around the plant.

How do you use Preen® Mulch Plus® with established annuals?

After plants have been set in the soil bed, spread Preen® Mulch Plus® over the area to a depth of 2″.

Does Preen® Mulch Plus® control weeds that are tilled under?

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

Can I use bare hands when handling Preen® Mulch Plus®?

No; wear gloves when handling.

Will rain wash Preen® Mulch Plus® away?

No; but heavy rains may shorten its effective period.


Can Preen® Mulch Plus® stain?

The colorant in Preen® Mulch Plus® can stain porous surfaces such as concrete, rocks, bricks, landscape blocks, shoes, leather, linoleum, etc.

How do I prevent possible staining?

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

How can I try to get rid of a Preen® Mulch Plus® colorant stain?

Try a pressure washer or a light detergent, such as Mr. Clean. Always test a small area first.

Storage & Safety

Where can I find emergency medical information for Preen® Mulch Plus®?

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

Does Preen® Mulch Plus® have any impact on earthworms or fungi in the soil?

No; the mulch component encourages soil organisms’ growth by moderating soil temperatures and conserving moisture.

Does Preen® Mulch Plus® contain termites or other insects?

No; Preen® Mulch Plus® does not contain termite-prone recycled wood materials. However, leave a 1″ to 3″ gap between the house and garden.

When can people and pets enter an area that was treated with Preen® Mulch Plus®?

After dusts have settled from application.

How do I dispose of Preen Preen® Mulch Plus® 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® Mulch Plus® expire?

No; it has an indefinite shelf-life as long as moisture and sunlight do not come in contact with the product.

Can Preen® Mulch Plus® be stored for next year?

Yes; store in a dry place away from sunlight and moisture and place cardboard or newspaper underneath the product.

What can I do if I applied Preen Preen® Mulch Plus® 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.

Use with Seeds and Young Plants

Will flower seeds germinate with Preen® Mulch Plus®?

Flower seeds will not germinate or reseed while Preen® Mulch Plus® is active.

When can I sow seeds or transplant non-recommended plants after an application of Preen® Mulch Plus®?

Wait 6 months from when Preen® Mulch Plus® was applied, except New York. In New York only, wait 4 months from when Preen® Mulch Plus® was applied.

Use Around Vegetables

Can Preen® Mulch Plus® be applied around an edible food plant?

No. Do not use Preen® Mulch Plus® around food producing fruit or nut trees, vegetables, herbs, or other food plants.

What do I do if I applied Preen® Mulch Plus® to vegetables, herbs, fruit trees, nut trees, or other edible food plant?

Remove Preen® Mulch Plus®, dispose of the plant in a non-compost area, then thoroughly water the area. Do not eat harvest from the treated area for one growing season; replant in one year.

Where to Apply Preen

Can I use Preen® Mulch Plus® in or near a pond, lake, or other type of waterway?

No; Preen® Mulch Plus® is harmful to aquatic life.

Can I use Preen® Mulch Plus® around, under, or near a swimming pool, sandbox, playground type areas, under bird feeders, etc.?


Can I use Preen® Mulch Plus® 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® Mulch Plus® where chickens, horses, etc. graze?


Can I use Preen® Mulch Plus® on a garden slope or hillside?

Yes; if a waterway is not at the bottom of the slope/hillside.

What plants are recommended with Preen® Mulch Plus®?

See our plant compatibility tool or the product label.

Can I use Preen® Mulch Plus® around a non-label recommended plant?

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. However, NEVER apply Preen® Mulch Plus® around plants the label identifies as injury-prone. [NOTE: Consumer assumes liability for any plant damage resulting from the use of Preen around plant species not recommended on the label.]

How close can I apply Preen® Mulch Plus® to a non-recommended plant?

We recommend keeping Preen® Mulch Plus® at least 12″ outside the drip-line from a non-recommended plant.

Can Preen® Mulch Plus® be used in potted plants or planter boxes?

Preen® Mulch Plus® is not labeled for use in closed containers, and will injure plants.

Where to Buy Preen

Is Preen Preen® Mulch Plus® available outside of the United States?

No; Preen Preen® Mulch Plus® is not available or registered outside of the United States.

Can I order Preen Preen® Mulch Plus® on your website?

No, but Preen Mulch Plus is available at Lowe's and independent garden centers nationwide. Use our store locator to find a retailer near you.

Weeds Controlled

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 Mulch Plus without selecting a size.

Rated 2 out of 5 by from Not so thrilled at the moment Just purchased this product for the 1st time last week - laid down 9 bags worth.......still have more to go......but now a week later - there are weeds and even some grass growing in some of the bedding that was "done". Seems like grass seed was in the mulch rather than weed preventer. Disappointed in that I'm not gonna get much of a break from weeding as I had planned .
Date published: 2017-06-26
Rated 1 out of 5 by from BAD COLOR! Purchased 39 bags of russet red at Lowe's over a two day period. Most came off the same pallet. After spreading, I noticed an obvious color difference in some areas. I waited a few days to let all the mulch dry, but the color difference remains, Very disappointed in this product!!
Date published: 2017-06-23
Rated 1 out of 5 by from Cut up pallet slats I hope this keeps the grass down because it looks like horrible. Hard to call it mulch. It truly looks like Preen took old pallets, smashed them and then dyed them brown. Looks horrible compared to the rest of my yard.
Date published: 2017-06-17
Rated 1 out of 5 by from Full of trash and 6-8" sticks and blocks We will not purchase this again after the last batch we bought at Lowe's. There were pieces of white glass and plastic bag material in it, aa well as a 5" long metal tube that was about a half inch in diameter. Also, a section of a wooden handle from a shovel or something. And there were a lot of really big pieces of sticks and blocks. The reason we don't get free mulch from the city is because it's full of trash and big pieces of "mulch." But we might as well get the free stuff if the bagged mulch that we have to pay for is no better. Do not buy this! By the way, this rating system forces you to answer the question "Did you receive a chance to win a prize for submitting a review?" with "Yes." There is no "No" option. No prize offered to me, just some really bad mulch.
Date published: 2017-06-17
Rated 2 out of 5 by from Quality Control Needed!! I bought 20 bags for my flower beds as I have done the last 5+ years. This year, the quality of mulch was disappointing when compared to previous years. I bought all 20 bags at the same time, from the same pallet at Lowe's and even with such a small volume, the quality and variation of color is unacceptable. Some of the mulch was a pretty chestnut brown while other bags are too black or even grayish and has created spotting where you can tell that the colors don't match in my flower beds. This color variation can be easily seen across the yard. I even double checked the plastic packages and made sure all 20 said chesnut brown due to how black some of the bags looked, but all 20 bags said chesnut brown. Also, the quality of mulch varied from bag to bag. Some bags had finely chopped mulch that looked more like shredded beef while other bags had much larger chunks of wood that averaged the size larger than fifty cent pieces. Several bags had garbage, larger chunks of wood and rocks bigger than ping pong balls. I even had some wood chips that had been previously polished and one looked like it was from something that had been painted red before being mulched. As far as weed control, I cannot not state whether this mulch will do the job seeing as I just put it all down. The mulch did have an earthy scent when I first put it down, but the smell isn't noticeable the next morning.
Date published: 2017-06-09
Rated 1 out of 5 by from Stay away! It stinks like cow manure! Do not use this product. Nowhere on the bag does it say it has cow manure in it, but it definitely stinks like it does! We had 15 bags of Preen Chestnut Brown Mulch put down in our flower gardens to get ready for a garden party this weekend. Now our backyard stinks like a dairy farm! It reeks like cow manure and has attracted a ton of flies! We are extremely disappointed and embarrassed because no one will be able to sit outside in on our backyard patio for the party this weekend because of the smell!
Date published: 2017-06-07
Rated 5 out of 5 by from Preen Mulh Plus An application of Preen Mulch usually provides six months of control for weeds in our flower beds. It is such a pretty color. It also helps retain moisture in the flower beds too where they are exposed to sunlight.
Date published: 2017-06-05
Rated 3 out of 5 by from Preen Question I just put down this product for the first time. I saw that it said I should NOT use this on Purple Cone Flower. I'm wondering if that means an established plant, or if that means seeds? I put it around an established plant and don't want to switch it out if I don't have to. I LOVE this idea, and hope it works:)
Date published: 2017-06-05
  • y_2017, m_7, d_25, h_7
  • bvseo_bulk, prod_bvrr, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_187
  • loc_en_US, sid_PRODUCT0013, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_preen
  • bvseo_sdk, net_sdk,
  • getReviews, method:CLOUD, 31ms
The PDF documents on this page may require the Adobe Reader to be viewed.
Get Acrobat Reader web logo
For Customer Service Call 1-800-233-1067 or Email Us