Blue couch facts for kids
Quick facts for kids Blue couch |
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| Scientific classification | |
| Genus: |
Digitaria
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| Species: |
didactyla
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| Synonyms | |
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Panicum bicorne |
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Digitaria didactyla is a type of grass often called blue couch or Queensland blue couch. It's also known as blue serangoon grass or green serangoon grass. In Mauritius, people call it petit gazon. This grass originally comes from Mauritius, Réunion, parts of Africa, and Madagascar. It has been brought to many other places. People mainly use it for pasture (where animals graze) and as turf grass. In some areas, it has started to grow naturally on its own.
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What Does Blue Couch Grass Look Like?
This grass grows in a mat-like way. It has special underground stems called rhizomes and above-ground stems called stolons. These help it spread. The stems can grow up to 63 centimeters long, but they are usually 15 to 30 centimeters. They creep along the ground and grow roots at their joints.
The leaves are narrow and can be up to 7 centimeters long. They are usually smooth and have a green to blue-green color. The inflorescence (which is the flower part) has 2 to 4 thin, finger-like branches. Each branch is about 7 to 10 centimeters long. Along these branches are tiny pairs of spikelets, which are small flower clusters, each less than 3 millimeters long. This grass can form a thick, leafy patch up to 20 centimeters tall. However, it stays shorter if animals graze on it or if it is mowed.
Blue couch grass looks a bit like southern crabgrass (Digitaria ciliaris). But blue couch has fewer and narrower flower branches. It also looks similar to bermudagrass (Cynodon dactylon). However, blue couch has shorter, wider leaves that are more blue.
How Does Blue Couch Grass Grow?
This grass can grow in many different kinds of soil. It can even grow in soil that doesn't have many nutrients or has a low pH (meaning it's acidic). But it grows best in lighter soils, especially sandy soils from granite. It can handle some shade and even occasional floods.
Blue couch grass usually survives in dry weather, but its leaves might shrivel. Frost also makes its leaves shrivel. This grass is very good at handling being grazed by animals or being mowed often.
This grass spreads easily using its rhizomes and stolons. This is a type of vegetative reproduction, meaning it grows new plants from its stems, not just seeds. It also makes seeds. These seeds can be spread in the poop of grazing animals and can stay alive in the soil for a long time.
Even though it doesn't always need fertilizer, the grass grows much better if you add nitrogen to the soil. Some good plants to grow with blue couch grass are legumes. These include three-flower beggarweed (Desmodium triflorum), glycines (Glycine spp.), pinto peanut (Arachis pintoi), Australian jointvetch (Aeschynomene falcata), Brazilian stylo (Stylosanthes guianensis), lotononis (Lotononis bainesii), round-leaf cassia (Chamaecrista rotundifolia), and white clover (Trifolium repens).
Sometimes, blue couch grass can get sick. It can get a disease called grey mould. It can also get the digitaria striate mosaic virus. This virus is spread by a small insect called a leafhopper (Nesoclutha pallida). Pests like spider mites (from the genus Oligonychus) can also bother this grass.
What Is Blue Couch Grass Used For?
For a long time, people have used this grass in pastures for livestock to eat. Animals like the taste of it. It is also planted as a lawn and used on golf courses. Many people think it is "one of the most popular lawn grasses in Queensland." It can also be used to cover the ground in other ways. It is very good at stopping soil from washing away.
There are special types of blue couch grass called cultivars. Two examples are 'Aussiblue' and 'Tropika'. These are grey-green types of grass that are good for lawns and sports fields.
Swazi Grass
Digitaria swazilandensis, also known as swazi grass or Swaziland fingergrass, is sometimes thought to be a type of D. didactyla. Other experts believe it is its own separate species. It is used for similar things as D. didactyla. Swazi grass feels rougher, is bigger, and is less blue. Its stolons are not as strong, but it makes fewer seeds. It spreads more often by growing new plants from its stems. It can also handle salty soil better and is more resistant to diseases.
