You can buy 2,4-D weed killer at most major home improvement stores, farm supply retailers, and online marketplaces. Because it is a concentrated herbicide used for both residential lawns and agricultural land, the best place to buy often depends on the volume you need (quart, gallon, or 2.5-gallon jugs). Major Retailers : Frequently stocks Gordon's Amine 400 in sizes ranging from 1 quart to 2.5 gallons. Walmart : Carries various brands like Southern Ag and . Lowe's : Typically stocks Hi-Yield 2,4-D Amine in the garden center. Ace Hardware : Offers professional-grade concentrates like Martin's 2,4-D Amine . Online Options Southern Ag Amine 2,4-D WEED KILLER, 32oz - Quart