The Q&A Archives: How long is Preen weed preventor effective?
Question: How long is Preen weed preventor effective? I've used it with transplants with great results for the past three years. Last application was June 1998, but now I plan to direct-sow annual wildflower seeds later this month (April 1999). I don't see any Preen granules left, and in fact, quite a number of cosmos, poppies and violets self-seeded from last year's garden in certain areas where there's no run-off. I'm wondering if it's OK to go ahead and direct sow, or will some remaining Preen from last year still prevent seed germination?
Answer: Unfortunately I am unable to give you specific information about individual proprietary products such as Preen. If you have questions about it, please contact the manufacturer.
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