Best garden irrigation system

Whether you're at home or on holiday, having a garden irrigation system set up in your greenhouse or on your patio can save you a lot of time and effort and keep your plants watered regularly.

They can be bought as a kit that comes complete with virtually everything you need, and this is the easiest way to get started. Most of them include a battery-operated timer, which is attached to a tap and programmed to automatically water at set times, but you can also get kits that use solar-powered rechargeable batteries in timers with integral pumps that can draw water from a tank or water butt anywhere in the garden. The researchers from Which? Gardening magazine thoroughly tested both types.

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Best garden irrigation systems

Only logged-in Which? members can view the garden irrigation systems test results below. Join Which? now to get instant access to our test scores and Best Buy recommendations below.

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Overall score: 93%

Price: Kit £38.49, timer £46.74

The soft and flexible tubing supplied with this kit really helped to make it easy to set up. All the components were well made and well designed, especially the large, super-adjustable drippers, which could deliver anything from a dribble to a flood. The timer, which we had to buy separately, uses a sensor to water at dawn and dusk, so you only need to set the number of minutes you want it to run.

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Overall score: 93%

Price: £76.79

This excellent kit includes 15m of larger-gauge pipe and 24m of smaller tubing to create spurs with terminal drippers. Joints for the main pipe include corner joints which make it easier to tailor the layout, and plugs let you block holes and change the position of the spurs if you move pots around. The timer has two outlets that can be programmed separately, and adjustable drippers with a good range of water flow.

Full results for garden irrigation systems

Only logged-in Which? members can view the garden irrigation systems test results below. Join Which? now to get instant access to our test scores and Best Buy recommendations below.

USING THE TABLE The more stars, the better. OVERALL SCORE Ignores price and is based on: Ease of setting up 25%, kit components 15%, flexibility of layout 15%, adjustability of drippers 15%, even flow rate over whole system 15%, flexibility of timer programming 15%. Ease of use rating includes clarity of instructions and how easy it was to do. Kit components rating includes the range of parts included and their quality.

Solar-powered garden irrigation systems

Solar-powered irrigation systems allow you to automatically water plants that are a long way from a tap as they are connected to a water butt or tank, but they have some drawbacks. The timer with integral pump must be higher than the water butt or tank to draw the water and must be in a sunny spot to charge, which can make placing them tricky. More of a problem, though, is the limited amount of water they deliver. One kit we used in the trial gave a maximum of 600ml per dripper per day and the other gave a very meagre 200ml per dripper per day. The water in your tank will last longer but larger containers will need several drippers to get enough water, reducing the number of pots the kit can cover.

 Buying and using an automatic watering system 

• Most kits need to be connected to a tap. If you want to connect your kit to a water butt or tank, you’ll need to buy a solar-powered kit.
• Check how much pipe is included in the kit so you know whether it will reach from your tap to the most distant pot. Most systems are modular and can be added to if needed.
• Check how many drippers are recommended for different pot sizes when deciding how many you need.
• If you rearrange your pots from year to year, either opt for a kit that allows you to plug holes so you can move the spurs or buy new pipe to make changes.
• The programmable timer allows you to adjust the amount of water going to the whole system, but adjustable drippers allow you to control how much water individual plants get, which is also important.
• When setting up the kit, make sure the pressure regulator is placed between the timer and the kit pipe, and always use the filter supplied with the timer to keep dirt out of the system. If your drippers become blocked with dirt, a small spike is often included to clear them.
• Check drippers regularly to make sure they’re working properly. Set your timer to water early in the morning and again in the evening if needed. Check and adjust your timer and drippers if the weather changes, to ensure you’re not over or under watering your plants.
• It is best to put automatic-watering systems away over winter to avoid the pipes freezing and then bursting. You can just unplug them and put them away; you don’t need to dismantle them.

How we test garden irrigation systems

• The Which? Gardening magazine researchers set up seven different watering kits for our trial. Five of the kits were designed to run off an outside tap, while the other two had a solar-powered timer with integral pump and could draw water from a water butt or tank.
• Timers were included with all but two of the kits. We were able to buy a separate timer from the same manufacturer for one of these kits, but that wasn’t an option for the other kit which we used with one of the other timers.
• Each kit was set up following the instructions and guidance provided. We noted the time taken and assessed the flexibility of the layout options and how easy the process was.
• We measured water flow throughout the system and adjustability of the drippers by putting containers under the drippers while they were run on a low then a high setting for two minutes. The amount of water collected was measured and compared to the manufacturer’s claims.