A watering can is one of those tools that seems simple until you use a bad one.
Personally, I like a proper 16-litre metal alloy watering can with a removable rose. Not plastic, for a start. Plastic cans have their place, but they can become brittle, split, fade, or end up being one more sad object blowing around the plot. A good metal can feels like a tool rather than a disposable container.
The size matters too. Sixteen litres is big enough to be genuinely useful when watering potato sacks, courgette pots, fruit bushes or a row of thirsty beans. It saves endless trips back and forward to the tap or water butt. But it does not have to be filled to the brim every time. For seedlings, delicate plants, or days when your back, wrists or thumbs are not in the mood, it can simply be half-filled.
That is the beauty of it. Big enough when you need volume. Manageable when you need control.
The removable rose is the other essential feature. With the rose on, you can give seedlings and loose soil a gentle shower without blasting them out of the bed. With the rose off, you can direct water straight to the base of bigger plants where it is actually needed. One can, two very different jobs.
Of course, the big metal can is not the tool for every job. Indoors, for houseplants, I use a much smaller long-spouted plastic watering can — about 3 litres, I think. That makes far more sense on a windowsill or among pots on a shelf. The long spout lets you get right to the compost without soaking leaves, furniture, books, plug sockets, or whatever else happens to be nearby. It is light, easy to control, and much less likely to turn a quick houseplant check into an indoor flood.
So this is not really about one perfect watering can for everything. It is about choosing the right can for the job: sturdy and generous outside, light and precise indoors.
A good watering can should last years, not seasons. It should be sturdy, repairable if possible, comfortable to carry, and useful for more than one kind of watering. Like many of the best allotment tools, it does not need to be clever. It just needs to be well made and used thoughtfully.