Water: you can’t always get what you want
During hot weather, water use rises dramatically as we sprinkle it on our gardens. In a dry summer, suppliers of water such as Greater Wellington Regional Council, may struggle to meet this demand. When water levels are low and predictions are for further warm dry weather, Greater Wellington asks cities to implement further water restrictions and steps up water conservation awareness campaigns. This doesn’t have to mean your garden won’t get the water it is gasping for.
Supplying water is expensive and it does not make sense to spend a lot on water storage for just a few weeks during the occasional dry summer. Water supply costs are also about more than just money, they are reflected in our environment too. It takes energy to treat water and to move it to your home. Energy generation, dams, water storage lakes and low river flows cost us natural resources as well as money. So spare a thought for these issues when you plan your garden. There may not always be as much water as you might want.
The most effective way to promote healthy plant growth is to use water sparingly and target irrigation to the soil, where it is most needed. Regular weeding, to reduce competition for water; and mulch, to reduce water loss from evaporation, are also necessary.
So how can gardeners care for their plants and conserve water? Only water plants, not paths and driveways and give them just enough water and no more. How 
much water? Give your garden enough water to wet the soil to about 10cm deep, usually half an hour of constant spray but longer if you are using a seep hose.
The right equipment will save you water, time and money. Check that the soil is dry several centimetres below the surface before you water, or watch your plants to see if they are wilting. If the soil is moist and the plants look good you will not need to water. Set the timer for about half an hour and check after watering to confirm that the soil is wet to 10cm deep. You may need to water every second day if the weather is hot and breezy, otherwise once or twice a week should be enough.
Think about the most convenient, effective system for watering your garden before you sow plants in the spring. What equipment will suit you best? See the Irrigation Product Guide for advice on what to buy.
Stick to the rules: one sprinkler system or hose at a time, only water on alternate days according to your street number (specific days of the week in Upper Hutt), only for two hours in the early morning or evening. These restrictions apply year round in Wellington and Upper Hutt and during daylight saving elsewhere.
Water in the vegetable garden
This is the part of a garden where it is essential to get the watering right. You will generally invest more time and money here than elsewhere in the garden. If you are relying on your garden for food then getting the watering wrong can be an expensive mistake. Group all your vegetables together rather than dotting them around the garden and the same goes for your flowers. Flowerbeds may look a bit naff but they’re a lot easier to water. Planning your garden around water needs will save time spent watering later. Space spray-jets to minimise dry spots and avoid wasting water on paths, lawns and driveways.
You need to water vegetables to maintain growth. Drought can cause some leafy plants (lettuces etc) to go to seed (bolt) and fruiting plants to produce small fruit or to drop fruit before it has ripened. For best flavour, many leafy plants need to grow rapidly and be harvested long before they begin to produce flowers. Small seedlings have only a few shallow roots and need constant moisture to grow well.
Lawns and shrubberies
The part of your garden least in need of water is the lawn. No matter how brown it turns over summer it will soon green up again with a little rain. Mature trees and shrubs do not need watering either. Less well established shrubs may need a slow soak once a fortnight. A seep hose for an hour or two should be enough. If you are expecting dry weather, keep weeds down and mulch thoroughly. Twenty centimetres of mulch is not too deep (see Mulch 101).
Some shrubs and many smaller flowering plants do very poorly under dry conditions. If you know that such conditions are common in your area then think about planting something more drought-tolerant. And remember, only plant new shrubs in winter and early spring when they will receive enough rain to become established before summer. For more advice on what shrubs to grow in your garden see the Regional Native Plant Guide.
