Nandhini Sundar talks to landscape architects who spell out the possibilities of having an expanse of green with half the expected usage of water
Talk about landscaping and the first thing that comes to mind is the copious amount of water required to sustain the greenery. This prompts many to shy away, opting instead for a range of pots and pebbled pathways. What is not known is the possibility of having an expanse of green with half the expected usage of water by simply planning the landscape right.
A large expanse of greenery can be opted for, yet conserve water through a process called Xeriscaping. This involves planning of the landscape in terms of the kind of plants selected, their placement, water run-off during irrigation, quantum of evaporation addressed, expanse of lawn required, its nature of use and the extent of walkways desired.
Plants essentially have different levels of water requirement and need to be grouped in accordance. Thus, plants requiring less quantity of water can be placed together in sunshine, as they fare better with less water as in the case of Bougainvillea, Gulmohar or exotic cacti that store water in stems.
Says Landscape Architect Kavita Sastry of Ecogyaan, “Plants requiring more water need to be grouped and placed under shade, preferably on the edges of the lowest levels of the landscape as this reduces the level of evaporation besides enabling the water run-off from lawns to accumulate amidst them, providing them with excess water while reducing wastage.”
Segregation of plants according to water requirement, besides saving water, also prevents excess water being supplied to plants that need less. Besides grouping, plants should be selected carefully where they belong to varieties that consume less water and are also native.
Bamboo & eucalyptus consume too much
Says Sastry, “Ornamental plants like Cacti, Geraniums, Adenieumobesum, Bougainvilleas, and Hibiscus are hardy and require less water. Geraniums and Adenieumobesum have colourful flowers and bloom in the dry season, providing a colourful flower bed in the landscape. So do flowering trees such as Acacia, Plumeria, Gulmohur, Pongamia and Neem. Plants like bamboo and eucalyptus are heavy water consumers and are best avoided.”
Reducing size of the lawn also conserves water. The plant varieties can be increased to expand the green cover. “Covering the edges or even dotting the landscape with less water-consuming trees would give the illusion of a larger expanse of green while reducing the expanse of lawn, thus conserving water,” adds Sastry.
The Bermuda green
According to Landscape Architect Malik Zahiruddin, of Malik’s Design Studios, “Functionality should be taken into consideration while deciding the extent of lawn cover. If it is not an oft-used lawn with heightened entertainment, Bermuda grass is a good choice as it requires 50 per cent less water compared to the Mexican variety which consumes copious quantities of water.”
Kentucky bluegrass and St. Augustine grass are other types which use less water, says Malik. “A major advantage of Bermuda grass is the liberty to let it go dormant when short of water. Reviving it to its green state requires regular watering for just a week as the roots remain alive beneath the brown exterior.”
The next step would be to decide the expanse of hard landscaping and soft landscaping. Hard landscaping pertains to pathways, decks and gazebos while soft landscaping addresses green spaces. Hard landscaping can be softened by opting for elements such as wooden seating, floral inlay work on stone pathways, pebbles with cuphea, and grass interspersed stone pavers.
While larger expanse of hard landscaping saves water, evaporation is a key element that needs to be addressed as it results in excessive wastage of water. Evaporation can be arrested by using a technique called mulching whereby the top layer of soil is covered by dry leaves, dead bark, even pebbles, if an organic option is not preferred.
According to Malik, mulching has been scientifically proven to reduce water wastage by 40 to 70 per cent. Says Sastry, “Mulching arrests weed growth and soil erosion and prevents fluctuation of soil temperature by creating a protective blanket over it.”
Creation of swales or rain banks also enable cutting down on water usage, says Malik. “Under this, a depression is created in the site, where the tallest plant varieties are placed followed by shorter varieties as the elevation of the site increases”, he adds.
Drip irrigation, recycling
Irrigation is the other aspect that needs to be addressed to reduce water wastage. Since evaporation is maximum during the day, it is best to irrigate at sunset, to enable water to stay longer in soil.
Sprinkler irrigation is not a good option for conserving water while drip irrigation is efficient especially with a rain sensor. In the absence of a large landscape affording the installation of an irrigation system, it is a good idea to opt for a hosepipe with holes punctured at periodic intervals.
Recycling household wastewater for landscape is a good option to conserve water. According to Malik, Phytoremediation is an efficient as well as an aesthetic option for cleaning kitchen and bath water for garden use.
“Plants like sunflower and lotus are excellent in taking away foul smell in wastewater, breaking down organic elements into micro nutrients and releasing fresh water into the landscape,” he says.
Their presence in the landscape also enhances aesthetics. The silt collected from phytoremediation can be used as organic compost for the landscape.