Is Preen safe to use for weed control near 1-year-old hydrangeas? What else would you recommend to control weeds in this planting area?
The Gardener’s Answer
Hi, Clare in Illinois: Weeds can be a serious nuisance for all gardeners. Keeping them under control is a task and anything that helps is well worth investing in. Preen is considered a pre-emergent herbicide that is used to prevent unwanted seedlings from sprouting. It is nonselective so it will also prevent any seeds that you intentionally planted from growing. It is perfectly safe to use around your hydrangeas or any other established plantings. The product has a three-month lifespan so it will prevent any seeds from germinating for a maximum of three months. It is not like spraying Round-up or any other nonselective herbicide with the active ingredient glyphosate. This will kill basically anything it comes into contact with. If you are using Preen around any edibles you might consider using their organic products. Corn gluten is another pre-emergent, organic option for weed control. As with any product be sure to read and follow all application recommendations.