Te tiaki wai i te māra
Saving water in the garden
Easy tips to help you grow with H2O.
From adding a trigger nozzle to your hose to watering at dawn and using mulch, there are several things you can do to make every drop count in your garden.
Whether you have a bountiful vegetable plot, a garden full of flowers or a smart lawn and a few potted plants, your garden needs water to grow. Making smart choices on the type of plants you grow, their placement and when you water can make a big difference in the amount of H2O you’ll need.
A water-efficient garden oasis awaits
There are lots of ways you can become more efficient with water use in the garden:
- Choose plants suited to Auckland’s soil conditions
- Use mulch to reduce the evaporation of water from the soil
- Water your plants at dawn
- Use a rainwater tank
- Reuse water from inside your home
Choosing plants for our soil conditions
Auckland has diverse soil conditions which can be prone to drying out during spells of hot weather. Choosing plants that grow well in these conditions means your garden will require less TLC, will be less prone to diseases and will naturally be healthier. Our friends at Auckland Botanic Gardens have helpful ideas on designing a garden that suits Auckland’s soil conditions.
For a healthy lawn, consider seed mixes that contain varieties of perennial ryegrass and fescue. Some varieties are designed to dry out and go yellow in summer, and it’s also better to let your lawn grow a little longer in drier months – it’ll stay greener and need less water than a closely mown lawn.
How to make the most of mulch
No matter the season, mulch is your friend. It can reduce evaporation from the soil by up to 70 per cent. Think of it as being a blanket on the soil.
Mulches moderate soil temperature, inhibit weed growth and, over time, improve the soil structure and health of plants. The basic rule is that any mulch is better than no mulch.
Horticulturalist, garden designer and writer Kevin Walsh, describes three kinds of mulch in his book, Waterwise Plants and Gardening (Reed New Holland, 2017):
Coarse mulch Coarse mulch, like pine bark, pebbles, recycled concrete and bricks, make a long-lasting mulch that’s excellent for preventing weeds. It’s also very good for keeping the soil cool, particularly if it’s lightly coloured. This mulch won’t improve the soil much and will take nitrogen out of the soil in the short term. To help, spread some nitrogen rich fertiliser on the soil before spreading the mulch. This sort of mulch can be 50 to 75mm deep.
Coarse mulch, like pine bark, pebbles, recycled concrete and bricks, make a long-lasting mulch that’s excellent for preventing weeds. It’s also very good for keeping the soil cool, particularly if it’s lightly coloured. This mulch won’t improve the soil much and will take nitrogen out of the soil in the short term. To help, spread some nitrogen rich fertiliser on the soil before spreading the mulch. This sort of mulch can be 50 to 75mm deep.
Medium mulchMedium mulch, like pine bark or wood chips, is excellent for reducing weeds. This sort of mulch is usually laid 25 to 50mm deep. One danger with mulch is watering too often, bringing roots to the surface of the soil under the mulch. If the mulch goes or the surface of the soil dries out, when the roots are too shallow, the plants die. The solution is less frequent watering.
Medium mulch, like pine bark or wood chips, is excellent for reducing weeds. This sort of mulch is usually laid 25 to 50mm deep. One danger with mulch is watering too often, bringing roots to the surface of the soil under the mulch. If the mulch goes or the surface of the soil dries out, when the roots are too shallow, the plants die. The solution is less frequent watering.
Fine mulch Fine mulch, like sawdust and euca, can stop water getting into the soil, so don’t make it too thick – about 25mm deep – and top it up each year when the ground is starting to dry out. Pea straw, cow and horse manure, and compost make excellent mulches because they improve the soil and attract worms.
Fine mulch, like sawdust and euca, can stop water getting into the soil, so don’t make it too thick – about 25mm deep – and top it up each year when the ground is starting to dry out. Pea straw, cow and horse manure, and compost make excellent mulches because they improve the soil and attract worms.
As well as using mulch, you can add compost to your garden. Good soil holds enough water for your plants whilst still being able to drain easily. Compost is great because its organic matter holds some water and helps to boost the nutrients in the soil – which is great news for gardeners.
Choosing the best time to water your garden
With Auckland prone to having a handful of seasons in one day, it’s a good idea to know when certain plants need a sprinkling of water from your watering can.
As a rule, watering at dawn should be your preference. Avoid watering at dusk, particularly after a hot day, because moisture resting on foliage overnight encourages fungal diseases.
Frequent light watering encourages shallow roots, so aim for longer, infrequent watering which allows the top layer of soil to start drying out before watering again.
Different areas and plants in your garden may need different watering patterns.
- Growing vegetables need 25 to 30mm of water per week for good growth. Water once per week by hand or when the top few millimetres of soil has started to dry out.
- Fruit trees normally need more water than smaller ornamental plants. Mixing plenty of organic matter into the soil prior to planting will help provide nutrients and retain soil moisture, reducing the need for watering. Keep grass and weeds clear of roots and mulch heavily to conserve water.
- Ornamental trees and shrubs need extra attention while they become established. Once the roots have grown deeper into the soil, they won’t need as much irrigation. Using lots of mulch around the roots will help reduce how often you’ll need to water them.
Using rainwater tanks
Using a rainwater tank enables you to collect rainfall from the stormwater system to use later in your garden. As well as utilising a free resource, you’ll be helping the environment by reducing stormwater runoff – and your garden will love it.
Here are some of the other benefits of using a rainwater tank:
- Collecting rainwater helps you prepare for times of low rainfall so you can still maintain your garden, even if there are water restrictions in place.
- You can use it to top up your pool or wash your car.
- Capturing rainwater reduces the load on stormwater systems because roof runoff is not flushed into the drains.
If you’re in the process of planning a new house, think about ensuring the design includes provision for a rainwater tank. Our friends at the council have more information about installing and using rainwater tanks.
Reusing water from inside and outside your home
There are a few ways you can reuse water on your garden.
- Keeping a bucket in the shower is a great way to collect water as the shower heats up for use on the lawn or garden. Remember, it’s not a good idea to use soapy water or water containing harsh detergents on your vegetable patch.
- If, when preparing dinner each night, you wash your vegetables in a bowl of water, that water can be reused to help grow the vegetables still sprouting in your garden.
- You can also use water ‘recycled’ from your fish tank on your plants.
- Wash your car on the lawn rather than the driveway or street. That way your lawn gets a drink when your car gets a wash.
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