Preparing your irrigation systems for winter - A simple guide

The days are getting shorter, and the weather is becoming bleak. It must be winter! Ensuring you decommission your garden irrigation system correctly will mean no nasty surprises in the spring when you set up your irrigation system again.

How to prepare a sprinkler system for winter

Following is a simple guide to precautions to ensure your irrigation system doesn't suffer from frost damage through the winter months. Take the time to do it now and you'll have fewer headaches when you come to use your irrigation system next year.

Do I need to winterise my irrigation system?

If you want your garden’s irrigation system to last, winterising and preparing your system for frost is absolutely vital.

If you decide not to winterise your system, it can cause permanent damage to irrigation systems. Be it sprinkler systems or hose pipes with spray nozzles, a freeze can easily damage the pipes, irrigation valves, sprinkler heads, and other components. Even if the damage is small, it could render the entire system useless, and you’ll have to spend time identifying the faults, repairing the system, or worst-case, replacing the entire system.

Winterising your irrigation systems in winter can also protect your home, as your waterpipes are liable to freeze and burst if your irrigation system is still connected to the tap and full of water. Any frost damage to your home and garden can be frustrating and expensive to deal with. Save yourself the headache and take the time to practise proper water irrigation care before winter.

Below we share some tips for protecting your irrigation system in the winter months.

Turn off the water supply

Turn off the water supply to the irrigation system from the main valve. This could be a garden tap for simpler systems or a dedicated shut-off valve for more complex systems. If you're using a water butt/tank with a pump, remove the pump, dry it off and store it in a dry place. Drain the water tank of water and disconnect any feeds from downpipes or mains water.

Store Water Timers indoors

Water timers don't do very well in freezing conditions. Most manufacturers will warn you that your tap timer can't be left outside in freezing conditions. Remove your water timer from the garden tap, empty it of water and store it in a dry place (preferably indoors). Unfortunately, manufacturers don't cover frost damage under their warranties, so this is really important to ensure you don't have to buy a new one at the beginning of the next watering season. For peace of mind, put it somewhere in the house as opposed to a garage, as the temperature in the garage can drop below freezing.

Drain your Irrigation System

When water freezes, it expands. This can cause hose pipes and other components to split, which is why it’s vital to remove as much water as possible from your pipework to prevent major damage. Removing stop ends is a good way for allowing water to escape. For pipework buried underground, you will need to install a drainage valve if you haven’t done so already. Although you won’t need to remove every single drop, the less water in the irrigation system, the better.

How to drain a sprinkler system for winter

If you have drain valves installed for your sprinkler system, then you’re in luck; it’s going to be as easy as shutting off the water supply to the irrigation system and then opening the drain valves for each sprinkler zone to release the excess water. Leave these valves open for a few days to be sure all the water has escaped, then close them again to stop any creepy crawlies from getting into the irrigation system. Remember to remove the water timer and store it in a safe place.

If you do not have drain valves installed, never fear; we can use an air compressor to blow out the lines of the sprinkler system to remove all the excess water. The blow-out method uses controlled compressed air to clear out water in the pipes and sprinkler heads to prevent damage to the system in freezing conditions. As this method can be dangerous if mismanaged, it may be best to call in a professional.

Protecting your irrigation system from wildlife in winter

There is no need to disassemble your irrigation system and store it away, it should be perfectly safe as is. There is one factor to bear in mind, however; wildlife. When you've been working in this industry as long as I have, you end up hearing it all. Typically at the start of each year, I have customers call and mention foxes (or other wildlife) have chewed through their system to try and reach the water. It's normally at the points water is released, such as micro jet heads or drip emitters.

You should also cap the end of your pipes in order to prevent bugs and insects from getting into your pipes and causing blockages. If you find that wildlife loves your garden, you may want to take steps to protect your irrigation system. This could mean going as far as disassembling it, or taping up emitters and outlets. It’s usually easier, however, to just repair any damage caused by critters then trying to prevent it.

How do I winterise my drip irrigation system?

A quick and easy way to ensure your drip system is always ready for winter is to install an automatic drain valve. Position it at the lowest possible point within the system. These valves' sole purpose is to let the water drain out and to protect your drip system from freezing and bursting. Otherwise, you can either install a manual drain valve or just remove the stop ends and let the water drain out. Close the drain valves or reinstall the stop ends when done to stop bugs crawling inside. Winterise your drip irrigation system by:

• Removing the timer from the tap. Drain the water from the timer. Remember to also remove batteries from the timer!
• Remove any other tap accessories. If you have any other tap accessories such as a tap splitter, you’ll also want to remove these from the tap,.
• Draining the supply lines. If you have a manual drain valve or end caps, open the end of pipes to let the water drain out, lifting the tubing at any low points. If you have automatic drain valves, you don’t need to do anything.
• Replacing the end caps. Cap off the ends of the tubes so no bugs can crawl in during the winter and block the pipe or emitters.

How cold is too cold for sprinklers?

It’s important to remember that anytime the temperature is freezing or below, it is probably too cold to run your sprinklers. Since the supply pipes are buried underground, there will be some protection if the air temperature dips to 0°C. That being said, if there is a hard freeze and cold for an extended period of time, do not run your sprinklers. Your lines must be drained or blown out before the first hard freeze of the winter season.

When to turn off the sprinkler system

The best time to shut down your sprinkler system will depend on your area's climate and when you can expect the first freeze. As a rule of thumb, you shouldn't use your sprinklers on grass if the temperature is below 4°C. The air may be above freezing, but the water on the grass blades will expose your lawn to wind chill which may freeze your grass.

Should you water before a freeze?

It is true that watering your plants just before a freeze can help keep your plants warm, but too much water or too little water could be damaging. For example, too much water may freeze leaves or damage roots. If you water the correct amount, you may increase your plants’ chances of survival during a freeze by:

• Increasing your plant’s soil’s ability to retain heat from the sun.
• Insulating the roots and retaining warmth for a longer amount of time.
• Protecting foliage and blooms as evaporating water retains heat better than dry air, providing a layer of protection.

Should you water the grass when it’s cold?

When watering your grass in the colder months, make sure to water during the morning. This ensures all the moisture will have time to soak into the soil before the temperature drops at night. Additionally, any water on the blades of grass will have time to evaporate before they freeze in the colder temperatures.

How often should I water the lawn in winter?

Your grass will need much less water in the winter than it needs in the summer. Colder temperatures call for only about half an inch of water as compared to the one to two inches required in the summer heat. Remember to consider your area’s typical climate and the amount of rain you receive in the winter. In the UK, we typically get enough rainfall during the winter to keep grass healthy, so I wouldn’t use my irrigation system.

If you have any questions whatsoever, you can give us a call and speak with one of our friendly staff. We will be happy to help and provide any extra guidence.