Planter Drainage Options: What Works and What Doesn’t

Yes, your planter needs drainage holes. The RHS says it is essential to have holes in the base of a container, because roots need air as well as water. If the planter you love has no holes, you still have good options: drill some, use a liner pot, or choose a planter built with its own drainage. This guide walks through each one, what to put (and not put) in the bottom, and how to spot trouble early.

TL;DR

• Every outdoor planter should have holes in its base so excess water can escape and air can reach the roots.
• If a pot has no holes, either drill them or double pot: keep the plant in its plastic nursery pot and sit it inside the decorative one.
• Cover large holes with crocks or stones to keep compost in. Lift pots onto feet or bricks so the holes never get blocked.
• A layer of gravel in the bottom is not a substitute for holes, and it takes up room your plant’s roots could use.
• Yellowing leaves, a soggy surface and a sour smell are early signs of waterlogging.

Table of Contents

• Why drainage matters more than most people think
• Your planter drainage options at a glance
• 1. Start with holes in the base
• 2. Drill holes in a planter that has none
• 3. Double pot when you cannot or would rather not drill
• 4. Use pot with no holes only with great care
• 5. What to put in the bottom of a planter
• 6. Lift the pot off the ground
• 7. Be careful with saucers
• 8. Consider a self-watering planter
• 9. Choose the right material and size
• How to tell if your planter has a drainage problem
• Our perspective: keep it simple
• Find planters that drain well
• Planters or raised beds: does drainage change the answer?
• FAQ
• Sources

Why drainage matters more than most people think

Waterlogging happens when compost is so saturated that water pushes the air out, so roots drown and can rot. The RHS notes that container plants are especially prone to waterlogging in winter, when rain keeps topping up pots and plants are barely drinking. A British autumn and winter makes this a real concern for anything left outside.

The University of Illinois Extension explains the principle simply: a hole at the bottom of a container lets water drain freely so enough air is available for the roots. Roots breathe. Take the air away and even a plant that loves moisture will struggle.

The same logic applies in the ground. Water that has nowhere to go sits and suffocates what grows in it, which is why gardeners with heavy soil talk so much about clay soil drainage problems. A planter without holes is a small version of the same trap.

Your planter drainage options at a glance

1. Start with holes in the base

The simplest answer is also the best one. A planter with generous holes in the base is the most forgiving option for outdoor planting. You can water thoroughly, let the surplus run away, and rain will not drown the plant in the way it can in a sealed container.

When you shop for planters, look at the underside as well as the front. Check that there are holes, that they are a sensible size, and that the base is not so flat that it seals against the ground. Many good-looking terracotta, resin and fibreglass planters come with holes or knock-out plugs that you open yourself.

If a planter has a small plug marked on the base, push it out before planting. It is far easier to do this on an empty pot than once the compost is in.

2. Drill holes in a planter that has none

If you already own a pot you love, adding holes is often the neatest fix. It suits plastic, resin, wood, metal and, with care, ceramic or terracotta. The golden rules are to work slowly, use a bit made for the material, and drill into a pot that is empty and steady.

For ceramic and glazed pots, a masonry or tile bit and a little water to keep the point cool will reduce the risk of cracking. Start with a small pilot hole and widen it. Our step-by-step guide to drilling planter drainage holes safely in UK gardens covers the tools, the safety points and the order of work.

How many holes? A medium pot usually does well with a few holes spread across the base rather than a single one in the middle. Bigger troughs and tubs need several, spaced along their length so water does not pool at one end.

3. Double pot when you cannot or would rather not drill

Double potting is the method the Illinois Extension describes as the most effective way to use a hole-free decorative container. You leave the plant in its plastic nursery pot, which already has drainage, and place that inside the decorative pot. Remember to lift the liner out and empty any water that has collected so the plant never stands in it.

A few practical tips make this work well:

• Choose a liner that fits. It should sit a little below the rim so the plastic does not show.
• Raise the liner slightly. An upturned small pot or a few pebbles under it keeps the base clear of any water that does collect.
• Check after rain. Outdoors, rain is the main source of standing water. Look in the outer pot after heavy showers and tip it out.
• Water in a sink or on the lawn. Take the liner out, water it thoroughly, let it stop dripping, then put it back.

This is also the easiest way to swap seasonal planting. Lift one liner out, drop another in, and the decorative pot stays put.

4. Use pot with no holes only with great care

Some people plant straight into a sealed container. It is possible, but it leaves almost no margin for error. Gardening writer Lindsey Chastain, speaking to The Spruce, explains that pots without holes starve plants of air and let minerals from tap water build up because they cannot be flushed through.

If you do use one on its own, The Spruce suggests watering the plant in a sink and then tipping the pot on its side after a few minutes so the excess can run out. That works indoors. Outdoors, where rain falls whenever it likes, a sealed pot is a gamble you will lose in a wet winter. For outdoor planting, we would always choose a holed planter or a liner.

5. What to put in the bottom of a planter

This is where most advice gets muddled, so it helps to separate two jobs.

Covering the holes

Big holes let compost wash out. The RHS advises using broken pots or stones to cover holes larger than about 2.5cm across, which stops compost falling through while water still escapes. Traditional terracotta “crocks” do exactly this. Homes & Gardens points out that large planters can use lightweight fillers such as broken-up polystyrene packaging to save weight, which matters when a big tub is full of wet compost.

Cover only the holes, with a single layer of crocks or a piece of mesh. You are screening the opening, not building a base.

Does gravel in the bottom improve drainage?

Not in the way most people expect. Water in compost is held by tiny pores, and it does not move easily into a coarser layer below until the compost above is saturated. The result is a wet band at the bottom of the compost, and a gravel layer simply raises that wet band closer to the roots while taking away room for compost. Many experienced gardeners therefore skip deep gravel layers altogether.

The better route to drainage is a free-draining compost, holes that stay open, and a pot that is not left sitting in water. If you want to improve the mix itself, adding some grit, perlite or bark to multi-purpose compost opens up the structure for plants that dislike wet feet, such as lavender, rosemary and many alpines.

6. Lift the pot off the ground

A hole is no use if it is pressed against a flat surface. The RHS recommends keeping holes clear by raising pots onto bricks or pot feet where possible. It takes seconds and it makes a real difference on patios, paving and decking, where water can otherwise sit under the pot.

Your choices include:

• Pot feet. Small terracotta or resin feet that lift the base by a couple of centimetres.
• Bricks or tiles. Cheap, stable and invisible behind the pot’s rim.
• A stand or shelf. Good for several pots at once and for putting plants at a comfortable height. Our guide to planter stands explains when to buy one and how to build your own.

One caution: a lifted pot dries out a little faster in summer, so check moisture more often in hot spells.

7. Be careful with saucers

Saucers protect a patio from drips but are a common cause of waterlogging. The Illinois Extension flags that permanently attached saucers can stop excess water draining and recommends detaching them where possible.

Outdoors in the UK, our advice is simple: use saucers in dry summer weather if you want to protect a surface, and remove them in autumn and winter, when rain does the watering for you. If you leave one on, empty it after rain.

8. Consider a self-watering planter

Self-watering planters are designed with a reservoir below the compost and an overflow so the plant draws up what it needs. They suit gardeners who are away often or who forget to water. They still depend on good drainage design, so look for a model with an overflow hole and fill it sensibly rather than to the brim. Our guide to self-watering planters and their pros and cons explains how they work, how often they typically need a refill and what to look out for.

9. Choose the right material and size

The material changes how quickly water leaves the compost.

• Terracotta is porous, so moisture also leaves through the walls. That makes it forgiving of overwatering but quicker to dry out. If you want to use it through winter, see how to seal terracotta pots for outdoor use.
• Plastic and resin hold water longer. They are lighter and need holes that are properly open. Our comparison of terracotta against plastic planters will help you decide.
• Glazed ceramic looks lovely but is often sold without holes, so check before you buy.

Size matters too. A very large pot for a small plant keeps a lot of damp compost around a few roots, and it will stay wet for longer. Our planter size guide helps you match pot volume to the plant. If you plan to paint a terracotta pot, read how to choose and apply paint for terracotta pots so you do not seal up the pores or the base.

How to tell if your planter has a drainage problem

Plants rarely say it outright, so look for patterns.

1. Yellowing lower leaves that drop even though the compost feels wet.
2. A soggy surface that stays dark and damp for days after watering.
3. Wilting despite wet compost. Drowned roots cannot take up water, so the plant looks thirsty when it is not.
4. A sour or musty smell when you lift the pot, or green algae on the surface.
5. Water that sits on top when you water, or runs out instantly with no resistance (this suggests a different issue: compost that has shrunk away from the sides).

If you suspect waterlogging, tip the pot and check that the holes are open, move it under cover for a spell, and let the compost dry a little before watering again. If roots are brown and mushy when you slide the plant out, trim the damaged parts and repot into fresh, free-draining compost. Look at the base afterwards: it is often a blocked hole.

Our perspective: keep it simple

We sell planters for a living, and the most common question we hear is whether a beautiful pot without holes is a mistake. Our view is that it is not, as long as you treat it as a decorative sleeve rather than a home for loose compost. Drill it if you can, double pot if you cannot, and put your effort into keeping water moving through the pot rather than into elaborate layers at the bottom.

The things that save the most plants are dull: holes that stay open, feet under the pot, saucers off in winter and a quick check after heavy rain. If you are buying new, look at the base before you look at the colour.

— Peter

Find planters that drain well

If you would rather start with the right planter than adapt one, browse our range of outdoor pots and planters. You will find a choice of styles and materials for patios, borders and balconies, so you can choose a shape and size that suits your plants and your space. Orders over £70 qualify for free delivery, and you can return items within 14 days if they are not right.

If you are still planning the layout, our Gardening section has tools and supplies to go with your new planters.

Planters or raised beds: does drainage change the answer?

If you are growing vegetables or a lot of plants in a small area, you may be weighing planters against raised beds. Both need good drainage, but raised beds sit on open soil and usually drain naturally, while planters rely entirely on their holes. Our article on planters versus raised beds sets out which suits which garden.

FAQ

Do planters need drainage holes?

Yes. The RHS describes holes in the base as essential for containers, because they let surplus water escape and air reach the roots. Without them, compost can become waterlogged and roots can rot, especially in winter.

What can I use for drainage in a large planter?

Cover large holes, those wider than about 2.5cm, with broken pots or stones so compost cannot fall out. In a big planter you can use lightweight material such as crushed polystyrene packaging to cut weight. Fill the rest with free-draining compost rather than a thick layer of gravel.

Does gravel at the bottom of a pot help drainage?

Not really. A gravel layer does not stop water gathering at the base of the compost, and it takes up space that roots could use. Holes that stay open and a free-draining compost do far more good.

What can I do with a planter that has no drainage holes?

You can drill holes, or keep the plant in its nursery pot and set that inside the decorative planter, emptying any water that collects. For outdoor use, avoid planting loose compost directly into a sealed pot.

Should I take saucers off my planters?

Outdoors in autumn and winter, yes, or at least empty them after rain. A saucer that holds water stops a pot draining and can leave roots standing in it.

Sources

• Growing plants in containers: Expert Guide, RHS
• How to plant up a container: Expert Guide, RHS
• Container Drainage Options, University of Illinois Extension
• Is It Ever OK To Use Planters Without Drainage Holes?, The Spruce
• What should you put in the bottom of a planter to aid drainage?, Homes & Gardens

Recommended

• 6 Safe Steps to Drill Planter Drainage Holes for UK Gardens