For those living in climates that regularly experience temperatures of 25 degrees Celsius or above, warm season grasses are likely better suited to your personal or professional lawn choices.
While cool season grasses are ideal for southern states like Tasmania and Victoria, where frost and colder temperatures are prevalent in winter months, warm season grasses reign supreme in Australian states like Queensland and Western Australia. In fact, warm season grasses can become dormant in southern states due to sustained cooler temperatures.
Also known as C4 grasses, warm season grasses thrive with warmer ground temperatures, often requiring more hours of direct sunlight than their cool season counterparts in order to survive.
Warm Season Species
The most popular warm season grass varieties include the following:
- Couch - Suitable for high traffic areas like fields, golf courses and parks, and thrives in the sunlight; high maintenance.
- Blue Couch - Adapts to sandy and acidic soils, and is less invasive than other species; low maintenance.
- Kikuyu - Repairs itself quickly, great under high usage areas, and grows quickly; low maintenance.
- Zoysia - Slow growth rate, very soft, and high tolerance for shade and heavy traffic; low maintenance.
- Buffalo - Excellent shade and traffic tolerance with lush look; low maintenance.
While Couch and Kikuyu are the most aggressive and invasive warm season grass varieties, Zoysia and Buffalo are much less aggressive and grow at a slower rate.
In addition, hybrid warm season grasses, which can be grown from either ribbons or stolons, include:
- Sir Walter - A Buffalo grass hybrid and the most popular choice in Australia, Sir Walter is resistant to insects, low allergenic, requires less water than other varieties, and has magnificent shade tolerance.
- Sapphire - A genuine soft leaf Buffalo grass hybrid, Sapphire is great at withstanding drought, has a slight blue hue, and is finer than other buffalo grass varieties. It is also less resistant to wear and tear.
- Wintergreen Couch - Requiring less water than Buffalo as well as minimal fertilisers, Wintergreen Couch has been a popular choice for golf courses due to its ability to recover quickly and its resistance to drought.
Warm season grasses can generate from both seed and runners, and allow the plant to spread and repair damaged areas through runners, stolons and rhizomes. For example, while Couch and Kikuyu have both stolons and rhizomes, Buffalo will only grow stolons.
Additionally, warm season grasses like Couch, Blue Couch and Zoysia can tolerate a lower HOC (height of cut) than their cool season counterparts at heights around 12mm. Meanwhile, Buffalo and Kikuyu are recommended at a minimum of 20 to 25mm.
When warm season grasses become dormant, you can simply add a Perennial Rye Grass (PRG) to add to the lush effect of the lawn.
One of the primary benefits of choosing a warm season grass is that it can be improved by regular mowing, as it promotes tillering, adding new leaves to the plant through new shoots, which gives thickness to the plant.