10 Best Pre Emergent Weed Killers 2025 in the United States

The Preen Garden Weed Preventer is a pre-emergent weed killer that promises to stop weeds before they start for up to three months. This product is effective at preventing new weeds from sprouting, which can significantly reduce the need for hand-weeding. It is safe to use around a wide variety of established plants, including over 200 types of flowers, vegetables, trees, and shrubs. However, it is not suitable for use on lawns, so its application is somewhat limited to garden beds and similar areas.

The product can be used throughout the year—spring, summer, or fall—which offers great flexibility in timing your garden maintenance. The granular formulation makes it easy to apply, especially if using a refillable flip-top applicator. Covering an area of up to 3,520 square feet, the 22-pound bag offers substantial coverage for large gardens. The environmental impact seems to be manageable given its specific safe-use claims, but users should always follow the recommended guidelines to ensure safety.

Its effectiveness is limited to preventing new weeds and will not address existing ones. This makes it a great choice for proactive gardeners looking to maintain weed-free garden beds, but less useful for those dealing with an already weed-infested lawn.

Scotts Turf Builder Halts Crabgrass Preventer with Lawn Food is a pre-emergent weed killer and fertilizer that effectively stops crabgrass and other listed weeds like barnyard grass, foxtail, and chickweed before they take over your lawn. It's designed to be applied in the early spring, before the temperatures consistently reach the 80s, and it is easy to apply to a dry lawn.

Following the instructions is crucial, as improper timing or application on certain grass types like Dichondra and Bentgrass can lead to unsatisfactory results. This product is formulated to cover a substantial area of 15,000 sq. ft., making it suitable for larger lawns. One notable advantage is that rain, snow, or freezing conditions after application do not reduce its effectiveness, ensuring consistent performance.

However, given its chemical nature, safety and environmental impact are considerations, especially if you have pets or children who play on the lawn. The dual function of preventing weeds and promoting a fast green-up after winter is a great benefit, but it requires accurate timing for best results. This product is best suited for homeowners looking for a comprehensive solution to both feed their lawn and prevent a variety of common weeds early in the season.

The Preen Garden Weed Preventer Plus Plant Food is a versatile option for anyone looking to manage weeds and feed their plants simultaneously. It is designed for use at any time during the spring, summer, or fall, making it highly adaptable to different gardening schedules. Its granule formulation ensures easy application and consistent coverage, with a single 31.3 lb. bag capable of treating up to 5,000 sq. ft. of garden space, which is quite generous for larger gardens.

The product not only prevents weeds but also serves as a balanced fertilizer, promoting abundant blooms, stronger roots, and increased yields, which is a significant advantage for those looking to enhance the health and beauty of their plants. It is safe around over 200 types of established flowers, vegetables, trees, and shrubs, adding to its versatility and safety profile. However, it's important to note that its effectiveness is primarily in weed prevention rather than weed removal, so it may not be suitable for gardens already struggling with established weeds.

Additionally, while it is generally safe for many types of plants, users should still check the specific compatibility with their garden plants to avoid any adverse effects. Users should follow the instructions carefully to minimize any potential environmental harm. This product is an excellent choice for garden enthusiasts looking for an efficient, dual-action solution to keep their gardens weed-free and well-nourished.