Sustaining Gardens in Dry TimesDocument Transcript
SUSTAINING GARDENS IN DRY T I ME S
A ckn o w l e d g e m e n t s :We would like to acknowledge the following individuals and companiesfor their assistance in the production of this publication:• Nursery and Garden Industry Victoria www.ngiv.com.au• Kevin Walsh, author of Waterwise Gardening, Reed New Holland, Third Edition 2004• Burnley Horticultural College www.horticulture.unimelb.edu.au• Royal Botanic Gardens, Melbourne www.rbg.vic.gov.au• Sustainable Gardening Australia www.sgaonline.org.au
The State Government’s Our Water selection, whilst still maintaining lush greenOur Future action plan aims to make lawns, healthy flower beds, shrubs andwater saving a permanent way of trees.life to secure our water supplies for future generations. With some 20 We recognise how important gardensper cent of household water used are to all our residents and the enjoyment gardening brings to many people.outdoors, we need to change our Gardens help people feel better,approach to watering the garden. encourage social interaction, increase use of outdoor space, reduce heating andWe want to share with you some practical cooling costs in nearby buildings by up toand immediate ideas on how you can 20 per cent, provide oxygen and absorbsustain your garden during dry times. significant amounts of carbon! The Royal Botanic Gardens, Melbourne, By following the advice in this brochure,provides a great example of water-saving you will not only save water, but alsosolutions in practice. It has reduced its money, time and our environment bywater consumption by 60 per cent over reducing stormwater run-off and urbanthe past 10 years, through improved water salinity, while still maintaining a rewardinguse and efficiency and changing plant and successful garden. Be rewarded for saving water. You can be rewarded for buying and installing a range of products for the garden via the Water Smart Gardens and Homes Rebate Scheme. Rebates are available on rainwater tanks, garden products including mulch and systems for re-using household wastewater. For further information and/or a rebate application form visit www.ourwater.vic.gov.au or look out for this logo when shopping.
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1D o n ’ t mak e ma j o r chang e sto yo u r gar d e n in s u mm e rSummer is the time to maintain and loses its moisture rapidly and combinedenjoy your garden. The ideal time for with water restrictions makes it hard fornew plants, installing irrigation systems gardens to recover.and other major changes is Autumn asthe garden has nine months to recover In autumn, particularly once rain hasbefore the heat of next Summer. fallen your new garden will be less labour intensive to create and moreYou will need to maintain your garden likely to prosper.in Summer by keeping up the mulch,pruning, increasing shade and reducingplants in pots. In summer disturbed soil For expert advice on how to create and maintain a water- efficient garden including plant selection, design and how to improve your soil, contact your nearest Water Saver Garden Centre. To find the location of your nearest Water Saver Garden Centre, visit www.ourwater.vic.gov.au and look out for this sign.
2M u lchMulch can reduce evaporation from soil This type of mulch can be 50 – 75mmby up to 70 per cent. Mulch is like a (3 inches) deep.blanket on the soil, keeping it cool andprotecting it from drying air and winds. Medium mulchWind is the biggest factor in drying out Medium mulches like pine bark or woodyour garden. chips are usually spread at around 25 – 50mm (2 inches) deep and areMulch also improves soil structure, excellent for weed prevention.increasing water retention, soil nutrientsand worm activity. Mulch is essential if Fine mulchyou are going to maintain your garden Fine mulch may include sawdust,through periods of low rainfall. And don’t grass clippings, rotted pea straw andforget, it’s covered by the Water Smart mushroom compost. It shouldn’t be laidGardens and Homes Rebate Scheme. more than 25 mm (1 inch) deep, as it may prevent water from reaching the soil.Coarse mulch An added advantage of fine mulchesChunky pinebark, fresh peastraw and is they break down quickly, attractinglucerne, pebbles and even recycled worms and improving the soil.concrete and bricks. All of these makelong lasting mulch and are excellent forweed prevention and keeping soil cool,particularly if the mulch is light-coloured.If using coarse organic mulches, spreadsome nitrogen-rich fertiliser on the soilfirst, as some nitrogen may be lost fromthe soil as the mulch breaks down.
3C O M PO S TSoil is a living thing. Compost increases Compost will assist in both these areas.organic content in the soil and provides Without good soil, no amount of watermaterial to keep the soil alive and full will allow your garden to thrive.of nutrients. The perfect growing soil is one that drains easily so it doesn’t get Compost is easy to make at home andwaterlogged, yet holds enough water to if you don’t have a compost heap, youfeed the plants. can start one by piling food scraps, leaves and garden waste. To find out more about making a compost heap visit www.sgaonline.org.au
4WATE R I N GHere’s a test. Before watering your garden, Observe them for signs of stress includingpush aside the mulch and put your finger wilting and leaf fall. You will be surprisedinto the soil. If it is moist below the surface, how tough many of your plants are!then you don’t actually need to water. Less frequent deep watering encouragesMany healthy plants in good soils deep rooted plants better equipped toare drought-tolerant and even in dry withstand hot, dry days.weather conditions will not needadditional watering once established. Check the four-day weather forecast atWith your existing plants try watering www.bom.vic.gov.au If there’s rain ahead,less frequently and then not at all. let the rain do the watering for you.
5R A I N WATE RTA N K SRainwater tanks are undoubtedly Tanks plumbed to the toilet and laundrypopular for saving water. Tanks are easy can be used effectively during periodsto use and now available in styles to suit of high rainfall when you don’t need toevery home. Rainwater tanks can also water your garden.provide you with free water allyear round and are not affected by Tank water should be used in preferencewater restrictions. to greywater, especially for herbs and vegetables. Even better, use tank waterIt’s best to invest in a tank that holds in conjunction with other recommendedat least 5,000 litres and have the tank water-saving measures like mulch, dripplumbed to your toilet and laundry. systems and soil additives.Toilets use approximately 14 per cent If you are in the process of planning aof drinking quality water in the house new house we encourage you to ensureand washing machines use around 16 the design includes provision for aper cent. The tank can also be easily rainwater tank.connected to outdoor taps and hoses.
At the planning stage you can arrange Don’t forget to use a licensed plumberfor a suitable space for your tank, when installing your tank, rainwaterincluding underground and bladder diverters and other work that involvesstyle tanks for under your decking. You alteration to plumbing fixtures, includingwill save water and add considerably down pipes and water pipes. Tanks of 600 litres or greater are eligible for a rebateto the value and enjoyment of both your when installed by a licensed plumber.house and your garden. water supply sewerage main pumpWater Smart Gardens and Homes Rebate Scheme Tank Rebate 1 (limit 1 per property) Rebate: $150 (tank only) For a rainwater tank for + Rebate: $150 (tank to toilet connection) (new tanks 600 to 1,999 = Rebate: $300 For a rainwater tank that collects water for use outside the home use outside your home litres, existing tanks 600 litres and is connected to a toilet (600 litres or greater). or greater). (600 to 1,999 litres). Large Tank Rebate 2 (limit 1 per property) Rebate: $500 Rebate: $900 Rebate: $1,000 Rainwater tank connected to toilet Rainwater tank connected to toilet Rainwater tank connected to toilet OR laundry (tank size 2,000 to OR laundry (tank size 5,000 or AND laundry (tank size 5,000 or 4,999 litres). greater). greater).Rebates are available for rainwater tanks of 600 litres or greater. Tanks must be installed by a licensed plumber,and a PIC certificate included with application. Visit www.ourwater.vic.gov.au for more information.
6G R E Y WATE RThis is a great option for supplementing cleaning agents and waste material, it isn’tgarden watering because it doesn’t rely suitable for all garden uses.on drinking water and isn’t affected bywater restrictions, however, it does need The best guide for using greywater in andto be managed carefully. around the household is the Environment Protection Authority (EPA) publication:Water can be recycled from your shower Domestic Wastewater Managementand washing machine but because it Series, Reuse Options for Householdcontains some bacteria, detergents, Wastewater.Greywater do’s and Don’ts do’s 3 3 nly use greywater from O don’ts 7 7 on’t water vegetable gardens D baths, showers, hand basins if the crop is to be eaten raw or and washing machines uncooked (preferably the final rinse 7 on’t use greywater that has D water) faecal contamination, for 3 nly use greywater on the O example water used to launder garden and rotate which areas nappies you water 7 on’t use kitchen greywater D 3 nly apply the amount of O (including dishwashers) due water the soil can absorb to the concentration of food 3 ash your hands following W wastes and chemicals that are watering with greywater not readily broken down by soil 3 top using greywater during S organisms wet periods 7 on’t store greywater for more D 3 top using greywater if odours S than 24 hours are generated and plants do not appear to be healthy
The most basic and popular greywater system for the garden is the humblebucket. Buckets are a good idea for watering your garden beds but shouldbe used with caution. A full 10 litre bucket weighs 10 kilograms and can bedifficult to manage, especially for the elderly.Never leave greywater in any container for more than 24 hours. Andremember, water restrictions do not apply when using a bucket for wateringyour garden with greywater.
G R E Y WATE RDiverting greywaterYou do not need permission to divert If you divert from the washing machinegreywater from the shower and washing make sure:machine away from the sewerage • he diameter of the diversion hose is tsystem during warm, dry weather for not smaller than the washingimmediate use. Greywater must not be machine hosestored for longer than 24 hours. You • the hose does not kinkshould however use a licensed plumber • he water does not have to travel uphill tand follow the EPA guidelines. and is not significantly slowed by travelling through the pipe (e.g. a veryThere are a number of products to divert long connection) or it maygreywater to your garden available from permanently damage the washingyour local garden centre, hardware or machine pump or burst the hoseplumbing shop. Usually people divert connection and flood the laundrywashing machine (final rinse) waterand shower water onto garden beds Some systems are now available thatthrough existing plumbing inspection do not treat greywater, but store ithatches or open doors or windows for less than 24 hours for irrigationonto the garden. on your garden. To be eligible for a government rebate, these systems must be EPA-approved and installed by a licensed plumber. WA N T TO K N O W M O R E For all information you need to know about greywater systems visit www.smartwater.com.au where you will find a useful study completed by the Alternative Technology Associations comparing six greywater systems.
G R E Y WATE RTreating and re-using greywaterfrom single householdsThere are systems available which you with a constant supply of usable water,can choose to treat and store your unlike rainwater, which is seasonal.greywater and use it as a long-term You can use this treated water to refillvaluable resource. your toilet (14 per cent of normal household use) all year round or supplyThese systems treat greywater to a your washing machine (16 per cent ofstandard so it can be stored indefinitely normal household use). Generally if youand used inside the house, but not for plan to use this water on the garden, thehuman consumption. These systems are treated water needs to be connected tousually priced at more than $5,000 sub-surface irrigation systems.and need to be installed by a plumberwith prior approval from the EPA. Don’t forget, the Water Smart GardensA septic tank permit from your local and Homes Rebate Scheme applies toCouncil is also required. the installation of approved greywater systems.Although this may seem an expensivealternative, a permanent greywaterdiversion system provides your home sewerage main overflow greywater system drip system
7WATE R W I S EPRACTISEThere are four key things to remember • Water the roots of plants rather thanabout reducing water use: the leaves reducing windspray and• Mulch evaporation• Drip irrigation • Cool season grasses should left longer in summer but warm season• Wetting agents and water storage grasses (couch, buffalo) can be kept products for your soil short• Drought-tolerant plants. • Avoid cutting grass by more than aAnd some simple yet highly effective tips: third of its length at any one time• Don’t water in the middle of the day, • Replace struggling plants in Autumn in windy conditions, or if rain is likely with drought-tolerant species• Make a small dam from mulch and soil to avoid water running off the soil
8R E V I E W YOU RPOT PL A N T SOutdoor plants in pots use a lot morewater than plants in the ground. Theyare more exposed to sun and wind, onlyhave a small amount of potting mix tostore water in and they dry out faster.If you need to minimise water for yourgarden, one solution is to reduce yourpot plants. Cuttings and nursery plantsshould be put into the ground in Autumn.Pot plants on terraces and small spaces When you water put the entire pot intothat you really love should be collected a bucket or container of water, leavingtogether out of the wind and preferably it until no more bubbles come fromin shade over summer. This will reduce the potting mix and then taking it outnot only the water you use, but the time and letting it drain, ideally back into ayou need to spend watering. container so the excess water can be re-used.The biggest problem with pot plants andraised beds is the soil drying out and The right plant, for example a succulent,becoming resistant to water. Wetting in good quality potting mix with soilagents can reduce pot watering by additives, mulch and a glazed pot will50 per cent and water storage products tolerate extended dry periods and can(see next page) in the soil will also look fantastic.extend periods between watering.
9S o i l a d d i t iv e sOne of the problems with soil that has Water crystals absorb water anddried out is it repels water, wasting the release it over time as the soil aroundprecious water you put on it. Soil wetting them dries out. Wetting agents enableagents and water retention products can water to soak in and water retentiondramatically improve the success of new products store water for later release.plantings and water absorption in yourgarden, particularly if it is already These items are included in the Watervery dry. Smart Gardens and Homes Rebate Scheme.
10I rrigat i o nAn earlier tip advises watering yourplant’s roots rather than the leaves.This raises an issue about the efficiencyof irrigation systems including sprayirrigation systems, which emit waterabove the ground surface, or dripper lines in their place. Drip irrigation systemssystems, which emit water at or below are not permitted to emit more than ninethe ground surface. litres per hour per metre of hose.Approximately 25 per cent of gardens Water restrictions only apply to mainshave spray irrigation systems. However, drinking water. You can use yourdrip systems are more effective as no rainwater or greywater quite efficientlywater is carried away by the wind, they with available technology and they aredon’t cause over spray and prevent not affected by water restrictions.excess surface evaporation. However, be careful about usingAs discussed earlier, we strongly greywater in drip systems unless it hasrecommend mulch for water-saving been well filtered. If the greywater is notgardens. Unfortunately, a spray irrigation filtered, it is likely the irrigation systemssystem operating above fine mulch will will block up very quickly.water the mulch rather than the plants,so much of the water is likely to be lostto evaporation, or absorbed by themulch rather than the soil below.There are products that allow conversionof spray systems to drip systems.This can be achieved by removingthe spray risers and inserting 6mm drip
I R R I G AT I O N Water weepers/porous hoses Simple, porous hose that sweats water outThere are many irrigation along its length. Ideally laid below mulchsystems available to in small trenches it can also be laid abovepurchase and install. This list ground in contact with the soil, but bestprovides a guide to some not laid on top of mulch.of the most popular ones.All are compatible with Flow rates are likely to vary over theexisting irrigation pipe sizes. length of the hose in uneven terrain andWe suggest you seek the depending on your water pressure.advice of a horticulturist,irrigation specialist or green The hoses can be combined with a filter,gardener when planning to flow regulator and pressure regulator.install an irrigation system. Flow rates are measured by the volume of water in litres emitted every hour, per metre of hose. VOLUME These systems are generally designed to PRESSURE operate at low pressure 60-100 KPa. Most systems will need a pressure regulator.
Dripper Systems Digital timersHoses with in-line drippers at Digital timers ensure you do notregular intervals should be placed water for unnecessarily longabove ground and below mulch. times and can be programmed in line with water restrictionsImportantly these are also (unless you have rainwater oravailable in 4mm versions that greywater).can be used to retrofit existingspray systems by removing the A rain sensor and a soil moisturerisers and inserting drip tubes. sensor can be attached to the digital timer to ensure efficientSome products have an inline and effective watering.pressure regulator and filter.Most products are not pressurecompensated so there may besome variation in flow rates based.Flow rates vary from4-10 litres per hour per metre.These systems are generallydesigned to operate at lowpressure 60-100 KPa.A pressure regulator will berequired.
11V E G ETA B LE G ar d e nsan d f r u i t t r e e sVegetable gardens and fruit trees are Fruit trees should be mulched and wateredan important aspect of many gardens. with a dripper system. Using good qualityIn addition to providing a source soil and maintaining healthy plant stockof food they reduce transport costs will mean the plants need less water andfor food provision and recycle will be more disease resistant.household waste through compost.As for the rest of the garden the key In very dry conditions and depending ontools are mulch, drip irrigation, soil water restrictions you might just addadditives and good plant selection. manure or compost in preparation for theThere is an interesting range of next crop. For fruit trees mulch well andrelatively drought-tolerant food plants. consider some early pruning to reduce water demand.You can mulch vegetable gardensand if you use pea straw it will also Consider using water from a rainwaterkeep your plants cooler and improve tank for your vegetable garden oryour soil, but you will need to replace fruit trees as this water is not affectedit regularly. Your irrigation system by water restrictions.will have to make allowances fordigging and soil renewal. A removableweeping hose under mulch canwork well.
To find out more about waterwise gardening see:Your local water retailer: www.savewater.com.auwww.citywestwater.com.au A one-stop-shop for water conservation.www.southeastwater.com.auwww.yarravalleywater.com.au www.bom.vic.gov.auWater conservation and water restriction Weather forecast information.information. Water Smart Gardens andHomes Rebate Scheme information is www.sgaonline.org.aualso available. At the Sustainable Gardening Australia site you can find advice on mulch to plantwww.ourwater.vic.gov.au selection and greywater systems. AlsoOur Water Our Future includes water includes addresses of certified Sustainableconservation and restrictions information Garden Centres.including the location of Water SaverGarden Centres and information about www.epa.vic.gov.authe Water Smart Gardens and Homes The Environment Protection Authority forRebate Scheme. greywater guidelines.Printed on Australian-made 100% recycled paper