Despite these dry times, with a little care you can still have a luscious lawn
Story: Sabrina Hahn
Lawns, I believe, are an essential element for softening the landscape and giving kids and pets a place to play. The new drought-tolerant lawns are fantastic and need no more watering than a native garden. Sir Walter Buffalo, Palmetto and Empire Zoysia are all excellent lawns suitable for a sustainable garden and don’t require watering at all in winter, and no more than twice a week in summer.
To reduce the risk of fungal diseases, water lawns in the morning rather than the evening. Certainly put out catch cups to check that the reticulation is reaching all parts of the lawn and not missing spots.
The controversy about lawns lies in the fact that we use them too much and in the wrong places. We shouldn’t waste our precious water on lawned verges or big areas in the front garden unless they’re used. Most people resort to lawn because they don’t know what else to plant. You could use your verge to create a nature garden that will bring your garden to life with all the birds and insects that help keep pests at bay.
Having a good lawn is all in the soil preparation, particularly in very heavy or sandy soils. Good drainage is also essential. If you live on heavy soils you’ll need to lay sandy loam to a depth of 10cm and incorporate gypsum or clay breaker into the topsoil. On very sandy soil incorporate rock dust, loam, and some blood and bone with added potassium. You can grow lawn from seed, runners, shredded turf and roll-on.
Couch
Varieties include: Greenlees Park, Wintergreen, Windsor Green, and Santa Ana.
A fine-leaf, winter-dormant lawn that is cheap and often used in parks. Couch lawn spreads by underground rhizomes, which is why it is such an invader in the garden. Santa Ana is used in golf course greens and bowling greens but must be well maintained to provide good results. A word of warning: Although couch is cheap, it is highly invasive and almost impossible to get rid of when in garden beds.
Buffalo
Varieties include: Buffalo, Sir Walter Soft leaf Buffalo, Palmetto, and Velvet Buffalo.
This is a coarse, vigorous lawn that spreads by surface runners so it’s not too much of a problem to control. The new strains of buffalo are the most drought-tolerant lawns on the market and don’t have the sharp edges that cause rashes on the skin. The new strains use no more water than a native garden. They are also relatively free from pest and disease attack and cover quickly.
Queensland Blue
Although it looks like a couch-based lawn, it’s a different species and has a blue tint with a softer leaf. Queensland Blue spreads by surface stolons or runners and is a far less invasive species than couch. It’s a beautiful, soft lawn that seems to have gone out of vogue.
Saltine
This is a salt-tolerant, soft-leaf lawn often used in areas where irrigation water has a high salt content. With maintenance saltine can be a nice lawn.
Zoysia Japonica
A new lawn that has recently hit the market and is described as being drought-tolerant and slow-growing, meaning there’s less mowing required. It has a lovely soft leaf and bright green colour. Most lawns that are slow growing have a tendency to be a little less hardwearing on heavy traffic areas but it’s well worth considering.
Kikuyu
This lawn spreads by stolons above ground and rhizomes underground, and gardeners who have it also say it’s possessed. Most racecourses, sports fields and golf courses use kikuyu as it is hardwearing and relatively drought-tolerant.
Fertilising lawns
Remember, an established lawn does not need any fertiliser containing phosphorus. If you are just laying a lawn, definitely use a pre-planting fertiliser and apply this with a wetting agent. You won’t need to fertilise again for six weeks. Most lawn fertiliser contains about 12 per cent nitrogen, so make sure you buy a good-quality lawn food that sustains regular growth and contains potassium.
You only need to fertilise at the beginning of each season, that is, four times a year. Gentlemen, please read this sentence again. Only fertilise four times a year. This will alleviate the need to mow the lawn every weekend. The amount of fertiliser to use is one handful per square metre. Most people use eight times that amount, with the result that all that fertiliser leaches into [local waterways] and feeds the blue-green algae. Ask the fish what they think of that.
If you over-fertilise your lawns with too much nitrogen, the leaf blade becomes highly susceptible to fungal diseases and sunburn. The plant cannot possibly take up all the nutrients so you’re throwing your money down the drain and into the river systems.
If you have a broad-leaf lawn it will benefit from vertimowing (see box) from time to time in the spring to remove thatch build-up and encourage new growth. Always fertilise and apply a wetting agent after vertimowing.
Trouble-shooting
Most questions relating to lawn care are to do with patches of lawn that are browning off. The most common cause of this is incorrect watering. The first thing to check is whether the water is penetrating to the root zone and is covering the whole area of the lawn. Invest in a set of catch cups, liquid wetting agent and a hand trowel. Dig up a small sod of grass to see how far the water is penetrating. You may need to use a wetting agent five times a year on your lawn. The new lawns require no more than two waterings a week.
The other common cause of browning off is a fungus called dollar spot, so named because it presents itself in small circles that become larger as the fungus spreads. Stop over-fertilising and spray with Mancozeb Plus or Professor Mac’s in the evening and do not water for the next four days. You may need to repeat spray two weeks later.
Read all about it!
Sabrina Hahn is the Perth-based author of Sabrina’s Little ABC Book of Gardening (published by Fremantle Press, rrp $19.95), from which this story was taken. Sabrina’s book, which is available in good book stores nationally, is full to the brim with handy gardening advice and tips on everything from caring for your lawn to planting vegetables and improving soil. Throughout the emphasis is on environmentally responsible solutions to common gardening problems.
What is vertimowing?
Vertimowing is a process to remove the excessive thatch that collects near the surface of a lawn. Thatch can prevent up to 75 per cent of water that is applied to a lawn ever reaching the root system. A thatched lawn will also suffer from having a scarred appearance when it is mowed.
The causes of thatch:
? excessive watering
? over-fertilising
? cutting too high in summer
? not mowing often enough
? using a rotary mower
The benefits of removing thatch:
? a healthier lawn
? greater water efficiency
? less fertiliser required
? a more even colour
? less chance of dry spot
? elimination of a breeding place for pests and fungus
Can we vertimow all Lawns? No. Runner type lawns such as Kikuyu and Couch varieties respond well to vertimowing. Buffalo lawns can be treated but will require special consideration.
Vertimowing is done with a special machine that removes the surface vegetation, allowing the roots and rhizomes to remain in the soil to regenerate the lawn. If the process is completed during the growing season of September to March, full coverage can be achieved in three to four weeks depending on the weather conditions.
After vertimowing, applying a wetting agent is recommended, as is checking your reticulation (irrigation system) to make sure it is providing even coverage. Also, regular cutting at the correct height is essential for a good looking lawn. It will also help to deter weeds and reduce the need for vertimowing.
Information supplied by the Lawn Mowing Contractors Association of Western Australia. For more information: www.lawnmow.com.au
