Grassy Weed – Redtop

(Agrostis alba)

Redtop – also referred to as Agrostis gigantea – is a perennial grassy weed that is occasionally used as a filler in low quality grass seed mixtures. Redtop can be found growing under a wide variety of soil and moisture conditions. It is able to thrive in very acidic soils, low fertility soils, and also poorly drained soils. Redtop can be found throughout much of North America.

Identifying Redtop -

Redtop can be identified as a blue-green colored perennial grass with a creeping growth habit caused by rhizomes. Its ligule is rounded and very tall, and its collar is narrow, divided into two parts by a space. The sheaths are smooth and not compressed, while the blades are flat, with prominent veins on upper surfaces and rough edges.

Because it is versatile and can grow in a wide range of conditions and soil types, Redtop is often used for erosion control and for stabilizing critical areas, including ditch and channel banks.

Redtop Control -

Redtop is not easy to manage using cultural weed control methods, although frequent, close lawn mowing can discourage it from growing. Of course, frequent, close mowing can damage other desired turfgrass species that might be present in your lawn.


Scotts LawnService recommends cultural weed control practices to reduce Redtop in your lawn and landscaping. This is due to the limited number of selective weed control product options to kill this weed. However, this weed can be controlled with non-selective weed controls such as Round-Up®, which will kill this weed and surrounding turfgrass. Re-seeding may be necessary to repair treated areas where Round-Up is used.

Scotts LawnService is the trusted industry leader for professional quality lawn care. Our exclusive lawn care products include premium grass seeds and professional-grade fertilizers; our lawn service teams are consist of highly trained, industry-certified professionals. Contact a representative today for Redtop control options available in your area and to learn how you can enjoy a lush, thicker lawn that only Scotts LawnService can deliver.