How to plant a concrete pot so it drains well and lasts

You have brought home a beautiful concrete pot and you want it to look that good for years, not split down one side after its first winter. The reassuring news is that a well made concrete pot is genuinely tough. When one does crack, it almost always comes down to how it was planted and where it was left standing, not to the pot itself. Get a few things right at planting time and it will outlast the plants, the trends and very probably the patio furniture.

Here is how to plant one so it drains well, sits steady and stays in one piece, with the reasons behind each step.

Why concrete pots crack, and why it is avoidable

Concrete is enormously strong under pressure, but it does not like two things: water trapped inside the pot, and hard knocks. Almost every crack traces back to the first. If a pot cannot drain, water collects in the soil at the bottom. On a cold Highveld night that water freezes, expands, and pushes the pot apart from the inside. The same thing happens when a drainage hole clogs, or when a pot spends July sitting in a saucer of standing water.

The RHS makes the link directly in its advice on containers in winter, which says to raise pots off the ground on pot feet or bricks to aid drainage and help prevent the freezing conditions that cause pots to crack. Solve the water problem and you have solved most of the cracking problem. The rest is simply handling a heavy pot with care, because like anything cast, a hard knock on a sharp edge can chip it.

Start with the drainage hole

This is the whole game. The RHS guide to growing plants in containers is blunt about it: it is essential to have drainage holes in the base of a container. If a pot does not have one, drill one with a masonry bit before you plant anything.

Once the hole is there, keep it doing its job. Lay a square of shade cloth, a piece of fine mesh or a broken bit of pottery loosely over the hole. That stops the potting mix washing out every time you water while still letting the water through. It sounds like a small thing, and it is, but a hole that slowly silts up with soil is an easy way for a pot that drained perfectly at first to end up waterlogged later on.

What goes in the bottom of the pot

You will hear two opposite pieces of advice about this, so here is what the evidence actually says. For years, the popular view was that a layer of gravel or stones at the bottom of a pot makes drainage worse, by creating a wet layer where the soil meets the stones. A 2025 study in PLOS ONE, Effect of drainage layers on water retention of potting media in containers, tested exactly that, using several drainage materials and potting mixes. It found that a drainage layer was likely to reduce the water held in the container and almost never increased it, and that thicker layers worked better than thin ones.

So a drainage layer does no harm, and it can help. In a large pot, it also saves you a lot of soil and money. That is what our Pot Filler is for: broken concrete pieces that go into the base of a big pot, keep the drainage hole clear, add stability and cut down on how much potting mix you need. Lay shade cloth over the filler so the mix does not wash down into it, then fill on top. The one thing a drainage layer can never do is replace a drainage hole. If the water has nowhere to go, no layer of anything will save the pot.

Lift it off the ground

Raise the pot onto pot feet, a couple of tiles or bricks. This one small move does a surprising amount. It keeps the drainage hole clear so water always escapes, it stops the pot standing in a puddle after rain, and it lets air move underneath. In winter especially, a raised pot cannot sit in freezing water, which is exactly the situation that cracks concrete. It also saves your paving from the damp ring and staining a pot left flat on the ground tends to leave behind.

Three or four feet, spaced evenly under the base, are enough for most pots. Our concrete pot feet come in small, medium and large, so choose a size in proportion to the pot, and set them before you fill it, because a filled pot is hard to lift.

Saucers, trays and winter

Saucers are useful indoors and on a balcony where water would otherwise drip onto the tiles or the neighbours below, and our pot trays and drip trays are made for that. Outdoors on open ground, they cause more problems than they solve. The RHS advice is to remove any trays or saucers before winter, so pots are not left standing in water. A saucer of water is also where mosquitoes breed, and the CDC recommends emptying and scrubbing water holding items like flowerpot saucers once a week. If you do use a saucer outside, empty it after rain.

Use the right mix, not garden soil

Fill the pot with a proper potting mix, not soil dug from the garden. Garden soil is too heavy for a container. It compacts, it stops draining, and that brings you straight back to trapped water and unhappy roots. We go into exactly why in can garden soil be used in pots. Match the mix to what you are growing, gritty and free draining for succulents and lavender, richer and more moisture holding for leafy plants. Our bark potting soil is made for outdoor pots and planters, and there is more on getting the mix right in the best type of soil for plants.

Leave room to water

When you fill the pot, stop a few centimetres below the rim rather than filling right to the top. That gap gives water somewhere to sit and soak in, instead of running straight off the surface and over the edge. It makes watering far more effective, and it stops soil washing over the rim every time you use the hose. A layer of pebbles on top then slows evaporation and keeps the surface neat.

Big pots and trees

Everything above matters more the bigger the pot, because a large pot holds more water and more weight. For a tree or a big statement plant, place the pot exactly where it will stay, set it level on its feet, add Pot Filler to the base and then fill it in place. We go through choosing the right size for the tree in what size pot does a tree need, and our guide to large garden pots covers filling and moving big pots without hurting yourself or the pot.

Looking after it through the seasons

Concrete pots ask for very little. Before winter, take away any saucers and check that nothing is trapping water around the base. On the Highveld, where frost is the main risk, our Johannesburg and Pretoria guide has more on getting pots through June and July. In Cape Town, the risk is weeks of winter rain rather than frost, and our Cape Town guide covers keeping pots draining through it.

Once or twice a year, give the pot a wash to lift the green film and dust that builds up on any outdoor surface. That really is all it takes. There is more on keeping pots looking good in how to choose pots that last and keep them looking new, and if you are still deciding whether concrete is right for you at all, our honest guide to concrete pots answers the cracking, weight and drainage questions in one place.

Frequently asked questions

Why did my concrete pot crack?

Almost always because water was trapped in the soil and froze. A blocked drainage hole, a pot standing in a saucer, or a pot flat on wet ground through winter are the usual causes.

Should I put gravel or stones in the bottom of a pot?

It does no harm and can help. A 2025 study found drainage layers almost never increased water retention and usually reduced it. In a big pot, Pot Filler also saves soil. It never replaces a drainage hole, though.

Do concrete pots need pot feet?

They are strongly recommended outdoors. The RHS advises raising pots on feet or bricks to aid drainage and help prevent the freezing that cracks pots. They also protect your paving.

Can concrete pots stay outside in winter?

Yes, as long as they drain. Keep the drainage hole clear, stand the pot on feet and take saucers away before winter so it never sits in water.

How do I stop soil washing out of the drainage hole?

Lay a square of shade cloth, fine mesh or a broken piece of pottery loosely over the hole before you fill the pot. Water gets out and the mix stays in.