Couch grass has creeping stems which can grow up to 20cm per week if conditions are favourable.
Couch grass is a perennial grass that spreads widely using underground runners. Couch grass can rapidly form large spreading colonies in lawns but it also invades ornamental beds as well as vegetable gardens and wild areas where it spreads through ground cover vegetation. Couch grass has creeping stems which can grow up to 20cm per week if conditions are favourable. Couch grass spreads widely through ground cover vegetation using long underground runners that develop at nodes along the length of the main stem. Underground runners continue to grow during dry weather because the plant draws up water from a large region of the surrounding soil. Couch grass has flattened seed heads, with the seeds dispersed by wind. Seeds remain viable for several years in soil seed banks if conditions are suitable, although germination rates tend to decrease as time goes on. Couch turf has a fine leaf and good shade and drought tolerance, and drought tolerance. The turf is soft to touch and ideal for areas like golf courses and other sports fields. Couch has good water efficiency and is ideal in areas with water restrictions.
Another way to differentiate between the two grass is from the leaves. Couch usually grows in mixed stands with long grasses and as a result, its leaf appears very long and slender to maximise sunlight absorption. Kikuyu is usually a stand-alone and its leaves appear stubby and thick. Couch has the ability to tolerate sunlight and the colour usually won't fade.
Couch grass cannot be killed with just one treatment, you must maintain regular control to ensure Couch does not re-establish in the lawn. Couch grass is hardy and always attempts to come back from the roots. Their growth habit can be controlled if Couch grass roots are uprooted. Couch grass lawn can be treated with selective herbicides such as Glyphosate. It is important not to use Glyphosate when there are few leaves on the plant otherwise the chemical will drift on to neighbouring areas that you may wish to keep. Couch responds well to Roundup treatment in spring when most of its energy has been redirected into new growth after winter dormancy, making it a good time for controlling Couch. The manufacturer instructions must be followed carefully when using any chemical product or risk damaging your lawns.
To control future growth of couch in your lawn, you must treat regularly - a minimum of twice yearly treatments or more. Couch grass' growth can be easily spread from lawn to lawn by people walking through it and is often moved around by pets so it's important to keep an eye out for new patches that need treating. By feeding the lawn correctly with high nitrogen fertilisers and watering regularly you can encourage a healthy lawn.
Couch grass is part of the Poaceae family which includes over 5,000 species worldwide, most of which are native to Australia. The difference between them is that some varieties are perennial and others annual. Perennial couch grasses can establish in an area and regenerate themselves year on year and can withstand drought. Annual couch grasses can establish in a region and regenerate themselves for only one season. There are more than 15 species of Perennial Couch in Australia, all of which fall under the genus "Agropyron". The annual species of Couch in Australia fall under the genus "Elymus". All couch grasses can spread quickly and it is one of the grass varieties that can reduce weed.