When to Water?
Getting it right
Understanding when to water to water your garden is really important. Has it just rained? Is it about to rain? How good is your soil at retaining water? Discover the best time to water your vegetable garden, pot plants or ornamental trees. Make sure you choose Smart Approved WaterMark watering products to ensure you water your garden efficiently when you water.
When to water?
- Only water plants early in the morning and late in the afternoon to reduce evaporation loss.
- Put your finger into the soil and if it is moist below the surface you don’t need to water.
- Check the weather forecast. If there’s rain due, let the rain do your watering for you.
- Only water the plant root zone to avoid wasting water where plants won’t use it.
- Watering at dusk after a hot day may be desirable but moisture resting on foliage overnight encourages fungal diseases.
Choose efficient water systems
Use drip irrigation under mulch if possible as this is the most water efficient method of garden watering. Find out more about how to choose water efficient garden watering systems here.
Look for the Smart Approved WaterMark logo on a product website or packaging so you know that the product you are buying is water efficient, durable, fit for purpose and environmentally sustainable. Products endorsed by the Smart Approved WaterMark have been reviewed by a credible, robust Independent Expert Panel.
Learn about watering for different types of plants!
Ornamental trees and shrubs
Freshly planted trees and shrubs will require additional attention to watering as they become established. As the roots grow deeper into the soil, they become less dependent on water available in the topsoil and irrigation becomes less critical. Heavy mulching of garden beds around trees and shrubs will minimise irrigation. The watering requirements of shrubs and trees varies enormously from species to species. For example, many Australian or South African plants may require no additional watering once established, while many exotics demand more water than is naturally available in order to survive.
Fruit trees
The water and feeding needs of fruit trees are normally greater than ornamental plants of similar size. Mixing plenty of organic matter into the soil prior to planting will not only help the plants access nutrients, but will also help the soil retain moisture, reducing the need for watering. Keep grass and competing weeds clear of root zones and again mulch heavily to conserve water.
The vegetable garden
Growing vegetables need between 25 and 50 mm of water per week for good growth. If watering by hand or with a sprinkler, a watering about once a week so that the water soaks to a depth of about 150 mm will often be adequate, repeated again when the top few mm of soil have started to dry out. A vegetable garden can be effectively watered by sprinklers, microsprays or drippers, but if using sprinklers, remember the need to avoid too much water standing on foliage, particularly overnight.
Plant pots
Groups of plants in containers may be watered as a group by sprinklers or micro-sprays, but the most efficient solution is to use drip irrigation, with individual running to each pot. Each dripper is fitted to the end of a piece of flexible feeder tube connected to a main polytube feeder. The flexible feeder tubes allow the pots to be moved about or changed at will. The flow rate of the drippers should be adjusted to suit the size and water needs of each plant.
Capillary pot watering enables a large number of pots to be watered simultaneously. Pots sit on a porous mat through, which water is circulated, to be drawn into the pots by capillary action. This labour-saving technique is best suited to nurseries and large greenhouses, with no wastage of water through run-off.
Avoid standing pots in saucers or on a surface, which may block the drainage holes or on which rainwater will collect and stand. Container plants require moisture to drain freely through the potting mix, otherwise their roots will rot. The solution can be found in small ‘feet’ which raise the pot from the surface, permitting free drainage. Water-absorbing granules mixed into the potting mix reduces the risk of plants drying out and allows longer spells between watering.
