Winterising the Garden: Shutting Down Water, Structures and Tools the Right Way

When should you actually start?

Water has the tightest deadline of anything on this list. The moment the forecast shows a night below freezing (0°C / 32°F), your outdoor faucets and hoses should already be drained, because freezing water expands by roughly 9 percent and that pressure has no trouble splitting metal, plastic or copper from the inside.

Everything else is less urgent, but it goes faster if you spread it over a few weekends instead of trying to do it all on one cold Saturday. A useful trigger is the point where you've genuinely stopped watering regularly — for most gardens in USDA zones 5–6 that's mid-to-late September, which is a natural starting line for the rest of the list.

This is about systems, not individual plants

This guide covers water, the greenhouse, ponds, hardscaping and storage — the infrastructure of the garden. Protecting specific tender plants from cold is a separate job with its own timing, and it's worth reading alongside our autumn garden checklist if you haven't already worked through plant-specific protection.

Shut off and drain the water supply

This single step causes more expensive surprises than everything else on this list combined. Water expands as it freezes, and that expansion has enough force to split a hose bib, a length of hose or a length of drip line without any warning until it thaws and starts leaking.

Good to know. A foam insulation sleeve around the outdoor faucet and the first section of pipe costs almost nothing and adds a buffer against one unexpected cold snap early in the season. It's a backup, not a substitute for actually shutting off and draining the line — it only buys you a few degrees, not a whole winter.

The same rule applies to drip lines running through raised beds or a greenhouse: the system needs to be empty of water, not just switched off at the timer. If you're not sure where your own drain points are, our guide to DIY drip irrigation walks through a typical layout.

Container gardens and balcony irrigation

If you run a drip timer to balcony pots or window boxes, the same rule applies: shut it off, disconnect it and drain the tubing before it comes indoors. A common miss on balconies is forgetting that a small reservoir or valve sits right at the timer itself, not just in the tubing that runs out to the pots.

Self-watering containers with a built-in water reservoir need to be emptied completely too. Both ceramic and thinner plastic pots can crack from ice pressure exactly the way a rain barrel does, so tip the pot over and rinse the reservoir out rather than just pouring off what's visible on top.

Winterise the greenhouse

A greenhouse left exactly as it was in August becomes a breeding ground for fungus and overwintering pests that will meet next year's seedlings head-on. The half hour you spend cleaning it in autumn genuinely changes how healthy the first crops look in spring.

• Clear out all plant debris. Spent tomato and cucumber plants can carry powdery mildew, blight spores and overwintering pest eggs. Bag diseased material for the trash, not the compost pile.
• Wash the glazing, inside and out. Grime and algae can cut winter light transmission by up to a fifth, which matters more than it sounds like once you're starting seedlings under low light in February.
• Check vents and doors still operate. A greenhouse sealed completely shut all winter traps moisture that encourages mould on both plant debris and the frame itself. Leave a vent cracked if the structure allows it.
• Think about roof load. A plastic-film hoop house or polytunnel rarely handles heavy wet snow as well as a glass structure with a proper frame. Clear the roof after any significant snowfall, especially early in the season before it has a chance to compact.
• Drain anything holding water inside. Water barrels, hoses or a small pump inside the greenhouse need the same treatment as the outdoor system.

Common mistake. Waiting to clear the greenhouse roof until the snow is already heavy and wet. Fresh, dry snow weighs surprisingly little, but the same volume of wet, late-season snow can weigh three to four times as much per cubic foot. Clear a thin layer often rather than letting it build up.

What about ponds and water features?

A garden pond doesn't need to be drained to survive winter — most are fine with a layer of ice on top as long as they're deep enough. The pump, filter and any fish are where the real decisions happen.

A surface pump left running under ice risks running dry if the water level drops, or simply wearing out for no benefit since it isn't doing much once the pond is frozen over. Most pond owners pull the pump and filter, clean them, and store them somewhere frost-free for winter.

Do you have fish?

Goldfish and koi can survive cold winters in a pond that's deep enough — generally at least 24–30 inches (60–75 cm) where it won't freeze solid to the bottom. What matters most is keeping one opening in the ice so gases from decomposition at the bottom can escape. A floating de-icer or an air pump that keeps a small area open is usually enough. Never smash a hole in the ice by force — the shockwave can injure the fish underneath.

Fountains and small water features

Smaller ceramic or concrete water features that aren't rated frost-proof should be emptied completely and stored under cover. Moisture trapped in porous ceramic freezes and cracks the material exactly the way a rain barrel does, and the damage often isn't visible until it thaws and starts leaking or falls apart.

Prepare the soil and empty beds

What you do with an empty bed now partly determines how the soil behaves come spring. Clay and sandy soils genuinely need different treatment here, so pick the method that matches what you're actually working with.

• Spread compost or well-rotted manure. Earthworms and soil microbes will work it in over winter, so you don't need to dig it in by hand.
• Sow a cover crop if there's still time. Winter rye or crimson clover sown in early autumn establishes enough to hold nutrients that would otherwise leach out over winter, then gets turned under or cut back in spring.
• Skip digging clay soil while it's wet. Working heavy clay when it's saturated destroys its structure and leaves hard clumps that persist well into spring. Wait until it feels roughly like a wrung-out sponge.
• Cover bare soil with leaves or straw. This protects against both heavy rain compacting the surface and weed seeds germinating during mild spells.
• Remove diseased plant material completely. Anything affected by blight or powdery mildew belongs in the trash, not the bed and not the compost pile.

Good to know. Mulched soil stays looser and slightly warmer through winter than bare soil, which can let you sow and plant a few days earlier in spring. A layer of cardboard or several sheets of newspaper under the mulch also suppresses weeds that would otherwise germinate during mild winter stretches.

For more detail on which materials work best as winter cover, see our mulching guide.

Extra vulnerable: raised beds and containers

Soil in a raised bed or a large container freezes faster and deeper than soil in open ground, because cold reaches it from the sides as well as the top. If the bed or container is empty over winter that's rarely a problem, but perennial roots left in a container are more exposed than the same plant growing in a border.

A simple fix is wrapping straw, burlap or bubble wrap around the outside of the bed or pot — not on top of the soil — which slows how fast cold penetrates the walls without trapping the moisture that encourages root rot.

Protect hardscaping, fences and outdoor wiring

The built parts of a garden handle winter better than plants do, but moisture and freeze-thaw cycles still wear on wood, metal and concrete left unattended for months.

Decking and patios

Sweep away leaves and debris that would otherwise rot and stain the wood, and check that boards drain freely. Water that sits in gaps freezes and thaws repeatedly, which breaks down both wood and joints faster than steady dampness ever would.

Gates, fences and locks

Oil hinges and locks before the first hard freezes arrive. Moisture that freezes inside a hinge or padlock can jam it completely, and that's a much more annoying problem to solve with ice on the ground than with an oil can in September.

Outdoor lighting and outlets

Check that outdoor connections and extension cords are intact and that no water can get into the fittings. Solar lights benefit from a wipe-down and a spot where they won't be buried in snow all winter — otherwise they charge poorly the moment daylight starts returning.

Pergolas and shade sails

Fabric shade sails and awnings should come down and be stored dry — heavy snow on taut fabric tends to tear both the material and its fittings. A bare wooden pergola frame without fabric handles snow load far better.

Tools, furniture and storage

This is the part of winterising that feels least urgent but saves the most money over a few years, since rust and rot move faster on poorly stored gear than most people expect.

• Clean and dry every hand tool before putting it away. Soil left on a blade holds moisture and starts rust within a week or two in a cold shed.
• Oil the metal parts of spades, forks and pruners. A thin coat of household oil or camellia oil keeps rust away over winter.
• Sharpen pruners and loppers while they're already out — you'll want a clean edge the moment pruning season starts.
• Drain fuel from gas-powered equipment or run the tank dry, since old gasoline can gum up a carburettor left sitting all winter.
• Bring in or cover outdoor furniture properly. Make sure cushions are completely dry before storage — trapped moisture in fabric goes mouldy fast inside a closed shed.
• Hang or rack tools instead of piling them. Ten minutes with a few hooks saves a lot of searching and blade damage every spring.

If you don't have proper storage yet, it's worth reviewing what's actually worth owning in our guide to essential garden tools.

What actually counts as "frost-free"?

Frost-free just means the temperature stays above freezing, not that the space is warm. An unheated but sealed garage or sunroom usually manages that on its own unless it's an extended deep freeze, while a drafty shed with gaps can end up nearly as cold as outdoors in a hard cold snap. If you're not sure, hang a cheap thermometer in the space during a cold week before trusting it with pumps, hoses or an irrigation controller.

What order should you do this in?

If you've set aside a single day, this is a reasonable order to work in. Water comes first because it has both the shortest window and the highest risk of damage.

1. Give the garden one last deep watering if it's been dry, especially newly planted material and evergreens that would otherwise head into winter already stressed.
2. Shut off the main valve to the outdoor water supply and drain the faucet and the first section of pipe by opening it fully until it stops running.
3. Drain and coil hoses, and shut off and drain drip irrigation or sprinkler lines.
4. Empty rain barrels and either flip them over or store them under cover.
5. Pull the pond pump and filter if you're not running them over winter, clean them and store them frost-free.
6. Clean out and rinse the greenhouse, and confirm vents and doors still operate properly.
7. Top empty beds with compost or mulch.
8. Sweep the deck or patio, oil gate hinges and check outdoor lighting.
9. Clean and oil tools, drain fuel from equipment and store everything in a dry space.
10. Bring in or cover outdoor furniture and confirm cushions are dry before storage.

How much time does it take by hardiness zone?

Water always has the tightest deadline no matter where you garden — a single unexpected cold night is enough to damage an unprotected faucet. How much you can spread out the rest of the list depends on how fast winter typically arrives where you live.

If you're not sure which zone your garden falls into, our month-by-month garden calendar walks through the full year and shows how this shutdown fits alongside everything else.

Common mistakes when winterising a garden

• Forgetting the interior shutoff valve. Closing only the outdoor faucet isn't enough — water can still sit in the pipe between the valve and the faucet and freeze there.
• Storing a hose that's still full of water. A hose that freezes with water inside splits along its entire length, even indoors in an unheated shed.
• Waiting too long to pull the pond pump. A pump still running after the pond starts icing over risks running dry or getting damaged by ice forming around the intake.
• Shovelling snow from a path straight onto the greenhouse roof. That extra load can be exactly what pushes a marginal roof past its limit.
• Sealing the greenhouse completely airtight. With zero ventilation, moisture builds up and encourages mould on both plant debris and the frame.
• Forgetting to oil locks and hinges. A frozen gate or a jammed padlock is a recurring annoyance that takes ten minutes to prevent.
• Packing away furniture cushions that are still damp. They'll go mouldy in storage long before summer comes back around.
• Digging over soil while it's still waterlogged. This wrecks soil structure and creates hard clumps that persist right into spring planting.

Frequently asked questions

When should I shut off the water to my garden?
As soon as the forecast shows a night below freezing, regardless of what the calendar says. In zone 6 that might not be until late October, while zone 3 and 4 gardens often need it done by mid-September. Metal and older plastic pipes split about equally easily from freezing, so there's no reason to wait just because a line is plastic.

Do I need to drain hoses even if the winter is usually mild?
Yes. Even typically mild winters get the occasional hard freeze, and it only takes one night for a full hose to crack. Draining a hose takes a couple of minutes, while replacing one costs a lot more than that time is worth.

What's the best way to protect an outdoor faucet from freezing?
Shut the interior shutoff valve, then open the outdoor faucet until all the remaining water and pressure has drained out. An insulated faucet cover adds extra protection but never replaces actually shutting off and draining the line — it only buys you a few degrees on one cold night, not a whole winter.

What should I do with my pond pump over winter?
Most gardeners pull the pump and filter, clean them and store them frost-free indoors. If you still want an opening in the ice for fish, a floating de-icer or a small air pump usually does that job better than running the circulation pump all winter.

Can drip irrigation lines stay outside all winter?
The tubing itself can often stay in place if it's fully drained, but valves, fittings and any irrigation controller are better off brought indoors. Double-check that the lowest points in the system have actually drained, not just that the main valve is closed.

Does a greenhouse need heating over winter?
No, not if it's empty or only holding hardy plants that overwinter outdoors anyway. An empty greenhouse just needs to stay clean, dry and reasonably ventilated. If you're overwintering tender container plants in it, you'll need frost-protection heat instead — typically a thermostat-controlled heat cable or a small space heater.

Should I dig over my vegetable beds before winter?
It depends on your soil. Heavy clay often benefits from being turned into rough clods in autumn, since freeze-thaw cycles break them down naturally by spring. Sandy soil rarely needs digging at all — a layer of compost or mulch on top is usually enough.

What actually happens if I skip winterising the garden entirely?
The most common outcomes are a cracked outdoor faucet or hose that isn't discovered until it thaws and leaks in spring, and a pond pump damaged by ice around the intake. It's rarely dangerous, but it usually turns into a repair bill for something that would have taken ten minutes to prevent in September.

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