Quick answer: The best large garden planters are 40 to 60cm wide, frost-proof, and heavy enough to stay put in wind. Fibreclay, stoneware and thick frost-proof plastic all cope with UK weather. Raise them on pot feet, check the drainage holes are clear, and choose one large planter over several small ones to cut down on watering.

Forty years on the same Sheffield allotment and I will give it to you straight: large garden planters are where most people either make their garden or throw their money away. Get a big pot right and it anchors a patio, feeds a family of tomatoes, and shrugs off a Yorkshire winter without a grumble. Get it wrong and it cracks with the first hard frost, keels over in the first proper gale, or drowns whatever you trusted it with. Here is what four decades has taught me about big pots that actually last.

None of it is clever. It is just the stuff the glossy catalogues gloss over.

What a big outdoor pot has to survive

A planter outside leads a far harder life than anything sat on a windowsill. Before you fall for a shape or a colour, make sure it can take the punishment.

  • Frost. Water in the compost freezes, expands, and shoves. A pot that cannot flex will crack or flake. Frost resistance beats good looks every time.
  • Wind. A tall, top-heavy planter on a light base is a disaster waiting for a windy Tuesday. Weight down low keeps it upright.
  • Water. More compost holds more water, so drainage holes are not a nicety. Standing water rots roots and splits pots in a freeze.
  • Weight when full. A big planter packed with wet compost is a proper heave. Decide where it lives before you fill it, because you will not be nudging it far afterwards.

Sort those four and the rest is just taste.

Match the planter to the job

Big pots are not one-size-fits-all, and I choose by what is going in them.

For structure and height on a patio, start with the large garden planters range, and the wider outdoor pots and planters collection for everything from troughs to tubs. Short on ground but greedy for growing? A vertical unit like the Wall of Green Vertical Planter gets a surprising crop off a small footprint, grand for herbs and salads against a sunny wall.

For anything thirsty like tomatoes, courgettes or bedding that sulks the second it dries out, a self-watering planter earns its corn every summer. The Self-Watering Window Trough keeps a reservoir underneath, so you are not out there twice a day in a July scorcher with the hose. The Royal Horticultural Society backs this in its advice on growing in containers: steady moisture is half the battle with big pots in summer.

Do not skimp on drainage and feet

I have lost count of the pots I have watched ruined because the water could not get away. Every big planter needs holes in the bottom, and lifting it clear of the ground helps the water actually leave, and stops the base sitting in a puddle that freezes solid come December. A set of pot feet, or a couple of offcuts of slate under the rim, does the job for pennies. Gardeners' World lays the principle out well in its guide to planting up a container.

After something taller for privacy, or to lift plants to eye level? Have a look at the tall planters range, but remember the wind: taller means you want more ballast in the base.

Filling a big planter without breaking the bank

You do not need to fill a huge planter with pricey compost right to the bottom. The roots mostly work in the top half. I part-fill the base with upturned old pots or chunky bark to save on compost and cut the dead weight, then top up with the good stuff where the roots actually live. It drains better and it costs less. A win twice over. For the full method on sizing and materials outside, our outdoor pots and garden planters guide covers it properly.

The honest summary

Large garden planters are worth doing well, because a big pot outside takes a proper hiding from our weather. Buy for frost resistance and a good heavy base, insist on drainage holes, lift the pot off the ground, and choose a self-watering design for anything thirsty. Do that and your big pots will still be standing, and still growing you a decent crop, long after the cheap ones have cracked and gone to the tip.

FAQ

What is the best material for large garden planters? Frost resistance matters most. Tough plastic and stone-effect composites handle a UK winter well and stay light enough to move; glazed and fired pots can look superb but check they are rated frost-proof before leaving them out over winter.

Do big outdoor pots need drainage holes? Yes, always. A large planter holds a lot of water, and without holes the compost stays waterlogged, rots the roots, and can split the pot when it freezes. Add holes and lift the pot off the ground on feet.

How do I stop a tall planter blowing over? Choose a design with weight low in the base, part-fill the bottom with something heavy and stable, and site it out of the worst of the wind. Taller planters need more ballast down low to stay put in a gale.

About the author Ted Mullins — Forty years with muck under his nails Ted has kept the same allotment plot in Sheffield for the best part of forty years and grows more than he and his neighbours can eat. He's potted on thousands of plants and has strong, hard-won opinions about frost, root rot and cheap plastic. He mentors newcomers on his site every spring. Writing for Potty for Plant Pots UK.