Beat the heat with lawn says SALI turf expert
With soaring summer temperatures experienced across the country, plants are taking strain and your lawn is no exception.
If you are contemplating removing lawn and replacing it with hard landscaping or artificial lawn, don’t be too hasty.
Despite a move towards low-maintenance and more water wise gardens, lawns do still have a role to play in city gardens. “Natural turf grass controls soil erosion as the root system grows into the soil and can be used to hold the soil on a gentle slope,” said Fanus Cloete, CEO at Evergreen Turf.
“Lawn also reduces heat when compared with hard rock surfaces, asphalt and concrete.”
Cloete explained that on a hot day, the temperature on grass may be around 17 or 18 degrees Celsius, compared to 55 degrees Celcius on asphalt.
“Grass also plays a role in capturing dust, smoke particles and other pollutants so air quality is improved,” said Cloete.
Lawns provide a place for entertainment in the garden and an area for children and pets to play. It compliments a garden’s design and, like all plants, it absorbs carbon dioxide and releases oxygen.
Buffalo grass (Stenotaphrum secundatum) is recommended for the winter rainfall Western Cape region and well as indigenous Cynodon species that are able to withstand periods of drought. Gulf Green, a Cynodon variety, is bright green in colour and suitable for a wide range of soil types.
The popular kikuyu is a warm season grass that requires at least six hours of sunlight per day to thrive. LM is tolerant of shade but not of drought and cold conditions. Although cool season grasses, like Shade-Over and Evergreen Gold, are green throughout the year, they do require more water.
Summer lawn care
Points to consider for a healthy lawn in summer.
Fanus Cloete says that it’s important not to mow your lawn too short in hot weather. “Leave it a little taller so there is enough leaf area for the plant to transpirate and cool down,” he added.
Aim for a mowing height of 20 to 25mm for warm season grasses and Cynodon species and 30mm for cool season lawns in sun and 50mm in the shade.
If your lawn looks whitish and takes a few days to bounce back after mowing, you are likely cutting it too short and exposing the softer parts of the leaf blade to the sun. Also check mower blades. A brown or whitish look may be the result of blunt blades.
When to water
Water thoroughly once per week rather than a few minutes every day. This encourages deep rooting which helps the grass cope better during periods of limited rainfall. Water in the early morning or after the sun goes down.
“Watch the colour of the lawn,” advised Cloete. “Most varieties will turn pale, brown or bluish when water is needed.” Don’t over-water your lawn. If you have an irrigation system, turn it off during rainy periods.
Under Cape Town’s current Level 3 water restrictions, municipal water (using a bucket or watering can only) may be used for watering plants before 9am and after 6pm on Tuesdays, Thursdays and Saturdays, for one hour per day per property. No hosepipes and sprinklers may be used. Opt for harvested rain water to irrigate your lawn.
“Grey water reuse is extremely helpful in maintaining a healthy lawn during times of drought and low rainfall,” said Mark Joubert of GardenResQ. “Grey water contains micro-organisms as well as many nutrients, which is then supplied to the lawn and plants that you are watering. Grass watered with grey water is often a very vibrant and healthy green.”
Never use water from sinks or dishwashers and keep grey water on your porpery. If you use laundry water, change to a detergent that is biodegradable. Never store grey water.
When to fertilise
Fertilisers are important to ensure that your lawn has good root system. “The deeper the root system, the healthier the lawn is and the deeper the roots will go to retrieve moisture in the soil,” explained Fanus Cloete.
Lawns should be fertilised at intervals of between 40 and 60 days. Whether you choose an organic or inorganic fertiliser is a personal choice. Inorganic products are available immediately to the plant, while organic products take time to break down in the soil.
For a chemical fertiliser, Cloete suggests a 5:1:5 fertiliser which can be use twice per year in September and February and a general LAN fertiliser during the interim periods.
Weeds look unsightly and if left unchecked in the lawn, they may choke out turf. Use an appropriate broadleaf herbicide to control them.
Watch for problems
Keep an eye out for lawn caterpillar, especially in January and February. They live below the soil during the day and come out at night to feed on grass, leaving behind dead brown patches.
To confirm lawn caterpillar, place a damp towel on the lawn overnight and check under it in the morning. Once confirmed, treat with an appropriate biological insecticide so birds can safely eat the dead caterpillars.
Dollar spot is a fungal disease more prevalent when the weather is hot, with periods of rain. Dead patches are straw-coloured and round in shape, about 25 to 50mm in diameter.
Brown patch is lawn disease also caused by a fungus and is more common during hot, humid weather. Both problems can be treated with an appropriate fungicide.
Source: Weekend Argus & Weekend Star, Independent Newspapers, 26 January 2018
This article is a response to a journalists enquiry - Why should homeowners stick with lawn rather than paving? Evergreen Turf CEO, Fanus Cloete responded.