Preen Mulch has an added weed preventer in it so it blocks weeds from germinating for six months. Each bag covers up to 12 square feet since it only needs to be applied to a depth of 2-inches to suppress weed growth, instead of the usual 3-inch depth recommended for other mulches. Available for purchase at Lowe's.

The most common ingredient in Preen products is an herbicide known as Trifluralin ("try-floor-a-Lynn").

Preen ® Garden Weed Preventer helps to prevent germination of seeds from the list of weeds shown on the label for up to 12 weeks per application. It does not kill or inhibit existing weeds in any way.

Garden Weed Preventer plus Plant Food prevents weeds and feeds plants in one easy step. Balanced fertilizer promotes abundant blooms, increased yields and strong root development. Safe for use around over 200 established flowers, vegetables, trees and shrubs.

Preen Natural Vegetable Garden Weed Preventer is made with 100 percent corn gluten, a natural herbicide that works as a pre-emergent - it keeps weed seeds from sprouting. And, Preen Natural Vegetable Garden Weed Preventer is safe to use around children and pets.

Preen is manufactured by the Lebanon Seaboard Corporation, a family-owned business headquartered in South Central Pennsylvania.

But if you don't want unsightly dead weeds in your garden. You still have to remove any existing weeds. And their roots by hand preen is not a weed killer. It's a weed preventer.

Mulch or stone. So that they're evenly.

trifluralin The active ingredient in Preen is trifluralin. It is a suspected carcinogen, and is toxic to fish and aquatic life, and earthworms.

Preen Natural Vegetable Garden Weed Preventer is made with 100 percent corn gluten, a natural herbicide that works as a pre-emergent - it keeps weed seeds from sprouting. And, Preen Natural Vegetable Garden Weed Preventer is safe to use around children and pets.

Harmful if swallowed or inhaled. Avoid prolonged contact with skin, eyes or clothing. with soap and water after handling.

While Preen is generally safe and effective for most types of gardens, there are a few situations where you should avoid using it. You should not use Preen on newly seeded areas or on areas where you plan to sow seeds in the near future.

Preen doesn't kill weeds, it acts on seeds. It stops weeds before they even sprout. Use as directed and you can use it with confidence around bedding transplants or mature plants.

Preen is mostly used during gardening; however, it can affect the environment when used excessively or wrongly. The main environmental impact of Preen is the contamination of marine life. A lake or a river will not benefit from weed management herbicides like Preen, intended to destroy plants or eradicate weeds.

Harmful if swallowed or inhaled. Avoid prolonged contact with skin, eyes or clothing. with soap and water after handling.

Harmful if swallowed or inhaled. Avoid prolonged contact with skin, eyes or clothing. with soap and water after handling.