Water scarcity over summer seems ever more challenging for gardeners. In a changing climate, the need to save water is increasingly front of mind. Water use charges and restrictions make things tricky for gardeners, especially over summer when plants need watering most. It ’s no coincidence that more urban gardeners are installing water tanks. Even a simple home-rigged rainwater barrel can make all the difference. Rainwater is free if it lands in your own garden.
Some plants need more water than others, but no plant can do without it. When plant cells suffer water stress they collapse, resulting in slower growth and often, irreversible root damage. So even after a plant appears to have recovered, it will lack vigour and become vulnerable to attack by pests and diseases.
Saving water in the garden so that every precious drop goes where it’s needed most is a multi-pronged approach.
|1||Fix leaky taps and hose fittings and treat yourself to new watering equipment for a more enjoyable and convenient watering experience.|
|2||Cover the ground. On a hot day, every square metre of bare soil can lose two litres of water to the air. The very best way to prevent this is to cover any bare soil with a blanket of organic mulch or weed-stopping groundcover plants.|
|3||Plant shelter. The drying effect of wind is markedly reduced when a windy garden is protected with a thick permeable windbreak. Trees and shrubs provide much more effective shelter than a solid wall, which creates turbulence. Once established, tree and shrub roots grow deep into the soil where there is enough moisture for them to grow without irrigation once they mature. Ideal for shelter in a windy climate include: Metrosideros (Pohutukawa), Pittosporum, Olearia, Corokia, Banksia, Coprosma, and Griselinia.|
|4||Group plants according to water needs. Lawns, vege plants and flowering annuals have shallow roots and need the most watering. Pots are also very water dependent. But deep-rooted perennials, trees and shrubs last much longer without watering.|
|5||Make your own compost and apply it regularly to build up your soil’s organic content and by doing so, improve its water holding capacity.|
|6||Train plants to cope with less water by gradually increasing the days between watering. Watering deeply once every week or two is infinitely more sustainable than a daily sprinkle.|
|7||Water early in the morning before the sun comes up and evaporates half your water. If mornings are too busy, enjoy watering in the evening.|
|8||Save hosing for your plants. Hand-watering with a hose is a relaxing way to begin or end the day and puts water where its needed, but a broom is best if you need to sweep the patio.|
|9||Install a trickle irrigation system. This delivers water exactly where plants need it and to the soil, not the foliage. Wet plants in summer can invite disease. Attach trickle irrigation to a timer to prevent waste and make things easier at holiday time.|
|10||Choose dry tolerant plants and drought tolerant lawn seed.|
|11||Use a wetting agent in pots and hanging baskets. This prevents dry potting mix from repelling water and helps distribute the water evenly throughout he potting mix. A wetting agent, such as Saturaid, can also be used to improve water holding in garden soil.|
|12||Install a rainwater tank, even if just a small one just for the garden.
FOR HEDGES AND WINDBREAKS
Pittosporum crassifolium (Karo)
Raphiolepis (Indian hawthorn)
FOR SUMMER COLOUR
Pachystegia (Marlborough rock daisy)
FOR HANGING BASKETS
Dichondra ‘Silver Falls ’
HERBS FOR FLAVOUR
FOR SANDY SOIL
Cacti and succulents
Silver foliage plants
Disphyma (Chatham Island Iceplant)
FOR CLAY BANKS
Flower Carpet roses
Carex secta (NZ tussock)
A 'rain garden' filters water through plants and soil.
A simple rainwater tank collects water for garden use
Beth Chatto's famous dry garden in England.
Armeria and groundcover succulents
Disphyma (Chatham Island iceplant)