Before your newly seeded turf is established in your yard, this ugly plant could cause a troublesome takeover. Unfertilized, acidic soil with a low nitrogen content encourages the speedy growth of this summer perennial. In addition, sheep sorrel thrives in areas with poor drainage and very little competition, so a weak lawn is the perfect target. Here's how to control it.
Initially, sheep sorrel spreads when its flowering stems disperse its seed from May until September. Once established, this pesky plant spreads primarily by an extensive, shallow root system, and underground stems called rhizomes. These stems allow for sheep sorrel to quickly form a loose, fleshy-leafed mat that is hard to kick.
Keep your lawn thick and well fertilized to fend off an infestation. Unless you are sure you have removed all rhizome, root and plant parts, sheep sorrel should not be removed by hand. Any leftover pieces will try to re-sprout after breaking off from the main plant. Instead, apply a Roundup® Brand Weed & Grass Killer on problem areas in your lawn. Do not spray on your turfgrass or garden plants, as this product will damage them.
Also known as red sorrel, this fast-growing weed shoots up long stalks with flowers that turn from bright green to reddish-brown. These slender stems can grow to be 6 to 18 inches tall, with its flowers clustered at the top end. Its oblong leaves, which are up to 3 inches long, grow in a ground-hugging rosette shape. Pollen on sheep sorrel's flowers is often the cause of hay fever all throughout summer weather.
