Container gardening is growing plants in pots, troughs, tubs and other containers instead of in the ground, and it is the way most people with a patio, balcony or small garden grow anything at all. It is flexible, it works anywhere there is light, and it lets you grow plants that would not suit your soil. It is also more demanding than growing in the ground: a pot holds little soil, so it dries out fast, runs out of food fast, and freezes harder in winter. This guide explains how to choose containers, fill them, water and feed them, and what grows well in them.
The appeal of containers is control. You choose the soil, so you can grow acid-loving plants in alkaline areas and Mediterranean herbs in heavy clay. You can move pots to follow the sun, to shelter from wind, or indoors for winter. You can grow a herb garden on a windowsill, tomatoes on a sunny patio, and flowers on a balcony that has no soil at all. The price of that control is attention: containers need watering, feeding and checking far more often than beds, and a pot that is forgotten for a week in summer can be dead by the time you remember it.
Choosing containers
Almost anything that holds soil and has drainage holes can be a container: terracotta pots, glazed pots, plastic pots, wooden troughs, metal tubs, fabric grow bags, and even old sinks and crates, as long as water can drain out. The material matters. Terracotta is attractive and breathable, but it dries out fast, it is heavy, and it can crack in frost. Plastic is light, cheap and holds moisture well, but it can look plain and it can overheat in strong sun. Wood is insulating and looks good, but it rots over time unless it is lined. Metal looks smart but heats up fast in sun and can cook roots. Fabric grow bags are light, cheap and drain well, but they dry out fast and last only a few seasons.
Size matters more than material. A pot that is too small dries out in a day, runs out of food quickly, and restricts roots so the plant never grows well. A pot that is far too large for the plant holds wet mix the plant cannot use, and the roots can rot. As a general rule, give a plant a pot that allows a season's growth: a tomato needs a large pot, roughly 30 to 40 litres, while a herb such as thyme is happy in a small pot. When in doubt, go larger rather than smaller, and use the soil volume calculator to work out how much mix you need. Always check that a container has drainage holes, and drill some if it does not — a pot without drainage is a pot that will kill plants.
Soil and potting mix
Do not fill containers with garden soil. Garden soil is too heavy for pots, it compacts, it drains badly, and it can carry weed seeds and disease. Use a good potting mix, or make your own from compost, coir or peat-free material, and perlite or grit for drainage. Our potting mix recipe gives a simple homemade mix, and the potting mix calculator — listed on the tools hub — works out the parts for any pot size. For Mediterranean herbs such as rosemary and thyme, add extra grit so the mix drains sharply. For leafy vegetables and flowers, a richer mix with more compost suits them better. Refresh the mix each year for vegetables and annuals: tip the old mix onto the compost heap or into beds, and refill with fresh mix, because old mix is exhausted and may carry disease.
Put a layer of crocks or gravel in the bottom of the pot only if it helps drainage — in fact, a layer of gravel at the bottom can make drainage worse by creating a wet layer above it, so most gardeners now skip it and simply make sure the drainage holes are clear and the pot is raised on pot feet. Mix in a slow-release fertiliser or a handful of compost when you plant, and plan to feed through the season, because a pot's food runs out fast.
Watering containers
Watering is the main job of container gardening, and the main cause of failure. Pots dry out far faster than beds, especially in sun and wind, and a pot in full sun on a hot day may need water twice a day. Water thoroughly, until water runs out of the drainage holes, and then let the pot drain — do not leave it standing in water. Water in the morning if you can, so the plant has the day to use it, and water the soil, not the leaves. Check the soil with a finger before watering: if the top few centimetres are dry, water; if they are still moist, wait. The watering calculator gives a starting point for how much water containers need.
Mulching the surface of a pot with gravel, bark or compost helps hold moisture in, and grouping pots together creates a more humid microclimate and shades the pots from sun. Self-watering pots and drip irrigation are worth considering if you are away often or have many pots — they are not a luxury, they are the difference between a garden that survives a holiday and one that does not. In winter, containers need far less water, and wet compost in a cold pot can rot roots, so water sparingly and make sure pots drain. Our winter houseplant care and winter frost protection guides cover the winter side of pots, which freeze harder than beds.
Feeding container plants
A pot holds a small amount of soil, so its food runs out quickly. Feed container plants regularly through the growing season, with a balanced liquid feed every week or two for hungry plants such as tomatoes and flowers, and less often for herbs, which prefer poorer soil and taste better for it. Do not overfeed: too much fertiliser burns roots and produces soft, leggy growth. Slow-release fertiliser mixed into the potting mix at planting time gives a steady supply for several weeks, and liquid feeding tops it up. Our fertilizing vegetables and fertilizing houseplants guides cover feeding in detail. Stop feeding in autumn and winter, when plants are not growing, and start again in spring.
What grows well in containers
Almost anything can grow in a container if the pot is large enough and the watering is right. Herbs are the easiest start: basil, parsley, mint, thyme, rosemary and chives all grow well in pots, and mint should only be grown in a pot, because it takes over a bed. Our growing basil, growing mint and growing rosemary guides cover the herbs. Salad leaves, lettuce, spinach and radishes are fast and easy in pots and troughs. Tomatoes, peppers, chillies and aubergines grow well in large pots on a sunny patio, if they are watered and fed reliably — see our growing tomatoes guide. Strawberries grow well in pots, troughs and hanging baskets. Flowers such as petunias, geraniums and trailing lobelia are made for containers, and bulbs such as tulips can be planted in pots in autumn for spring colour. Our growing tulips guide covers the planting side.
Choose plants that suit the light you have: a shady balcony will not grow tomatoes, but it will grow ferns, hostas and leafy herbs. A sunny, windy balcony will suit herbs and Mediterranean plants, but it will dry pots out fast, so water more often and choose larger pots. If you are unsure what will grow in your conditions, check your local extension service for advice.
Pros and cons of container gardening
The advantages are flexibility, control over soil, mobility, and the ability to garden with no ground at all. The disadvantages are the work: watering, feeding and repotting are all more frequent than in beds, pots freeze harder in winter, and a large pot of wet soil is heavy to move. Containers also cost more than beds, because you buy pots and potting mix. None of these is a reason to avoid containers — they are reasons to choose the right size, the right mix, and a watering routine you can actually keep up. Start with a few pots, learn what they need, and add more as you gain confidence.
Common mistakes
The most common mistake is a pot with no drainage holes, which drowns the plant. The second is a pot too small for the plant, which dries out and starves it. The third is using garden soil instead of potting mix. The fourth is underwatering in summer, especially on a sunny patio. The fifth is overwatering in winter, which rots roots. The sixth is forgetting to feed, so plants run out of food mid-season. And the seventh is forgetting containers in winter, when they freeze harder than beds and need grouping, wrapping and sparing water. If you are unsure about containers for your space, check your local extension service for advice.
Frequently asked questions
What size pot do I need?
It depends on the plant. Herbs are happy in small pots, salad leaves in a trough, and tomatoes need a large pot of roughly 30 to 40 litres. When in doubt, go larger rather than smaller, and use the soil volume calculator to work out how much mix you need.
Why do my container plants keep dying?
Usually watering: too little in summer, too much in winter, or a pot with no drainage. Check that the pot drains, check the soil with a finger before watering, and water thoroughly when you do water. Old, exhausted mix and lack of food are the next most common causes.
Can I use garden soil in pots?
No. Garden soil is too heavy, compacts, drains badly and can carry weed seeds and disease. Use a good potting mix, or make your own from compost, coir and perlite or grit.
How often should I water containers?
In summer, check daily — pots in sun and wind may need water every day, and large pots on a hot day may need it twice. In winter, water sparingly. Always check the soil first, water thoroughly, and let the pot drain.
Do container plants need feeding?
Yes, regularly through the growing season, because a pot's food runs out fast. Feed hungry plants such as tomatoes and flowers every week or two with a balanced liquid feed, and herbs less often. Stop feeding in autumn and winter.