Winter storage: protecting your can from freeze damage

The risk of freezing

If you live somewhere that freezes in winter, water inside or within a partially filled watering can poses a structural risk. As water freezes, it expands. If the can contains water or is left exposed to rain, an ice plug can form. The expanding ice creates internal pressure that seeks release at the weakest point of the structure.

In metal cans, this pressure commonly forces outward against the base, which can deform. If freezing cycles repeat, the base can eventually split. In plastic cans, the pressure typically builds along structural weak points such as mould seams or joins, and splitting commonly occurs along these lines.

Simple prevention: empty before storage

The straightforward solution is to empty the can completely before winter if there's any risk of freezing in your area. This is the most effective way to avoid freeze damage.

Store the empty can in a sheltered location — a shed, garage, or covered area where it won't collect rainwater or snow. If the can is completely dry and empty, freezing temperatures cannot cause damage.

During winter use in cold areas

If you continue to water during winter in a region with regular freezing:

•        Empty the can promptly after use

•        Do not allow it to stand with water in it overnight or during cold spells

•        Store it indoors or in a frost-protected location between uses

Even brief periods of freezing can begin the damage cycle. Prevention through emptying is far more reliable than relying on the can to survive freeze events.

Spring and autumn transitions

If temperatures fluctuate around freezing in spring or autumn, the same principle applies. If you're not using the can regularly and there's a risk of overnight frost, empty it and store it dry.

This is particularly important for outdoor storage — if the can is left in a garden shed or cold frame during a freeze, and it contains water, damage can occur.

Plastic cans and freezing

Plastic cans are equally at risk. Because blow-moulded plastic cans are formed as a single piece with mould seams, the splitting typically follows these structural lines rather than appearing as overall deformation.

The prevention is identical: empty and store dry.