Waterwise irrigation

Article originally published by: Kiwi Gardener

It’s thirsty times for our prized plants. Make sure they don’t dehydrate by following our guide to waterwise irrigation.

Installing a simple irrigation system can save you many hours of watering by hand

The first days of summer are finally here and what better time to consider the long and balmy season ahead – and in particular how your plants might continue to thrive during the inevitable dry spells.

Water’s the key of course, so whether it’s installing a complete irrigation system, saving rainwater or simply getting out there with the watering can, there are plenty of ways to deliver your plants a well-deserved drink.

All systems go

Installing a simple irrigation system is a reliable option and although there may be some expense (and work) involved in setting it up, there’s no reason why such a system shouldn’t last for years and save you many hours of watering by hand.

Drip irrigation is the most efficient way to water with moisture slowly delivered to the roots through a main pipe via a series of holes and valves. Keeping the soil steadily damp in this way reduces evaporation and wind drift and also ensures water is only directed to specific plants. Ideal for the vegetable garden, this slow-release method of watering also works well on sloping land, lessening the chance of run-off.

Weeper pipes do exactly as their name suggests

Another popular piped irrigation system works on the principle of an interconnected series of plastic pipes fixed around the garden (or a specific area of the garden) with mini spray heads inserted directly into the pipe and directed at specific plants. This looped system works particularly well when fixed around raised beds and larger pots – which may require more watering than beds at ground level – and systems like this can even be run overhead to regularly water hanging baskets (which are particularly vulnerable during hot, dry weather).

If cost is a factor, there’s no reason why an ordinary garden hose may not do a similar job. Simply stop the end with an appropriate plug and then fix the hose around a raised bed or along the base of a fence using pipe brackets. Carefully drill a series of small holes along the length of the hose (this is a more controlled way of puncturing the hose than with a hammer and nail) and connect the hose to the garden tap. Although the hose will deteriorate from UV damage over time, it should last a couple of summers.

A temporary solution

If you don’t want to install a fixed, permanent irrigation system there are a number of moveable options for keeping plants well-watered, including the good old garden sprinkler, weeper pipes and soaker hoses – even a hand-held hose or watering can. All these options have the advantage of being portable and relatively inexpensive and can be put away when not needed.

A good old watering can is the ideal way to redistribute collected rainwater

When shopping for a sprinkler, do check the label for the spray range and purchase according to your needs. A small vegetable garden may only need coverage of a few metres but a large lawn will need considerably more.

As the name suggests, weeper pipes are porous and once connected to the mains supply, water pressure forces its way through the tiny pores, causing the pipe to ‘weep’ water. Like the drip irrigation system, there’s no spray with this device, resulting in less evaporation and no wind drift. These are great for looping round newly planted trees and shrubs or for running along a line of crops, such as runner beans.

Soaker hoses come in a variety of lengths from about seven and a half metres to 30-plus metres and consist of a flexible plastic pipe, punctured at regular intervals to deliver a line of fine water jets along its length (especially good for watering a long border). There is a potential downside to soaker hoses though, in that the further the water travels along the hose, the less pressure there is (resulting in weaker water jets towards the end).

What better way to admire all your hard work at the end of a day outside than with a glass of something cold in one hand and a hose or watering can in the other? Hand-watering can actually be quite a contemplative task, giving you an opportunity to really see how your plants are developing and providing time for ideas (as well as seeds) to germinate. If using a hose choose a spray head with a soft spray to avoid potential damage to plants.

A rain barrel with a tap is a great addition to any garden

Going green

With water metered in some areas of the country and for those not on mains supply, it makes more sense to collect and reuse rainwater where possible. Divert rain run-off from sheds and garages directly into a water barrel where it can be redistributed around the garden using a watering can.

Grey power

Reusing greywater (water from sinks and washing machines) is another option, although you will need to install a suitable greywater system to correctly divert and manage the waste water. This may also require council consent, so contact the appropriate authority in the first instance.

Top tips for watering

  • To prevent over-watering, fit a mechanical timer to your garden tap before connecting the sprinkler. Set the dial for up to two hours of watering time.
  • If watering with sprinklers or any type of spray irrigation, use them early in the morning or later in the day to lessen the chance of evaporation.
  • Don’t forget potted plants, especially if you’re going away during a dry spell. Rigging up a simple reservoir of water with a pipe may be all it takes to keep them going in your absence.
  • If you have a water barrel, fit a handy tap near the bottom and raise the barrel up high enough to get the watering can underneath the tap.