Container flowers are how colour fits into a garden with no beds — a balcony, a doorstep, a paved courtyard, a windowsill. A pot of petunias by the door, a hanging basket of trailing lobelia, a window box of geraniums, a tub of dahlias on a patio: each of these is a complete flower garden in miniature, and together they can make a paved space feel like a garden. Containers also give you control a bed never can: you choose the soil, you choose the spot, and you can move the display when the season changes.
The trade-off is the same as for any container planting: a pot is a small world, and it dries out fast, heats up and cools down fast, and runs out of nutrients sooner than the ground. Container flowers need more regular watering and feeding than the same flowers in a bed, and the pot itself matters as much as the plant. Get the container, the soil and the watering right, and a container flower garden will flower for months.
The best container flowers are the ones that flower for a long season and do not mind a pot. Petunias, geraniums, marigolds, calibrachoa, trailing lobelia and verbena are the classic basket and pot flowers, and they will flower from late spring to the first frost if they are deadheaded and fed. Dahlias grow well in a large tub, and a single dahlia in a pot can be the centrepiece of a patio. Tulips and daffodils grow well in pots in spring, and a pot of bulbs by the door is the easiest spring colour there is. If you are unsure about a variety, a spray, or a diagnosis, check your local extension service — its advice is matched to your climate and soil.
Choose the right container — and mind the drainage
For flowers, the container can be almost anything — a terracotta pot, a glazed ceramic pot, a window box, a hanging basket, a wooden planter, a fabric grow bag — provided it has drainage holes. Flowers sitting in water will rot within days, and a pot without drainage is a pot that will kill them. Terracotta breathes and keeps roots cool, but it dries out fast and can crack in a frost; glazed ceramic holds moisture better; plastic is light and cheap but heats up in sun; a hanging basket dries out fastest of all and needs a liner that holds moisture. Size matters: a small pot dries out in hours on a hot day, while a large pot holds moisture for days and gives the roots room to grow. For a summer display, use the biggest container you can manage, and for a hanging basket, use a large one with a moisture-retentive liner. Put the container on pot feet so water can drain freely, and place it where it will live before you fill it — a full tub of wet soil is heavy to move. The potting mix calculator can help you work out how much compost a container needs.
The right soil mix and planting combinations
Fill flower containers with a good-quality potting mix, not garden soil, which compacts and drains badly in a pot. A mix based on composted bark or coir, with perlite for drainage, suits most flowers, and a slow-release fertiliser mixed in at planting time will feed them for the first weeks. For a display that lasts, plant in the thriller-filler-spiller pattern: a tall, upright flower in the centre — a dahlia, a geranium, a spike of salvia — surrounded by mounding flowers such as petunias and marigolds, with trailing flowers such as lobelia or calibrachoa spilling over the edge. Plant closely — closer than you would in a bed — because a container display should look full from the start, and the plants will fill the gaps within weeks. Do not mix flowers that want very different conditions: a lavender that wants dry, poor soil will not thrive next to a petunia that wants rich, moist soil. Group plants with similar water and sun needs, and the display will be far easier to look after.
Watering container flowers: the daily habit
Container flowers dry out far faster than flowers in the ground, and in hot weather a hanging basket may need water twice a day. Water deeply until it runs from the drainage holes, then wait until the top inch of mix is dry before watering again — a finger pushed into the mix is the best guide. Water in the morning, so the plants have water for the heat of the day and the leaves dry quickly. A water-retaining gel or a mulch of bark on the surface of a large tub will slow drying, and grouping pots together shades their sides and slows evaporation. Self-watering pots and drip irrigation on a timer are worth the investment if you travel or work long hours, because one missed watering on a hot day can finish a basket. The watering calculator and the watering schedule generator can help you set a routine for your containers.
Feeding and deadheading for months of flowers
Container flowers need regular feeding, because nutrients wash out with every watering. Feed every two weeks through the season with a balanced liquid feed, or use a slow-release fertiliser at planting time and top it up in midsummer. Petunias and geraniums are hungry and will stop flowering if they are not fed; marigolds and zinnias need less, but they still flower better with a regular feed. Deadhead every few days: pick off the faded flowers of petunias, geraniums, marigolds and dahlias, cutting the stem back to the next leaf or bud, and the plant will keep making new flowers instead of setting seed. For petunias, pinch out the growing tips in early summer to make a bushier plant, and in midsummer, cut a leggy basket back by a third — it will look bare for a week and then flower better than ever. Remove any yellowing leaves, and check under the leaves for aphids, which love the soft growth of a well-fed container plant.
Seasonal containers: spring bulbs, summer colour, autumn interest
A container garden can change with the seasons. In spring, plant pots of tulips, daffodils and hyacinths in autumn, and put them by the door where you will see them every day — a pot of tulips is the easiest spring colour there is, and our growing guides for tulips cover the varieties. In summer, replace the bulbs with petunias, geraniums, marigolds and dahlias, and keep them watered and fed until the first frost. In autumn, plant winter pansies, heathers and ornamental cabbages for colour through the cold months, and add a few spring bulbs underneath them — the bulbs will push through the pansies in spring, giving you two seasons from one pot. In winter, protect tender containers from frost by moving them to a sheltered wall or wrapping the pots, and water sparingly. A container that is replanted each season is a garden that never has an empty moment.
Common container flower problems
The commonest container problems are easy to recognise and to fix. Wilting on a hot afternoon usually means underwatering, but wilting in wet soil means root rot and the pot is not draining — check the holes and the saucer, and never let a pot stand in water. Yellow leaves can mean overwatering, underwatering or hunger, and the pattern tells you which: yellow all over with weak growth usually means hunger, and a feed will help; yellow lower leaves in wet soil usually means overwatering. Leggy, stretched growth with few flowers means too little light — move the pot to a sunnier spot. Aphids cluster on the soft shoots of a well-fed plant, and a jet of water will knock them off. Slugs climb into pots on the ground and eat the low leaves — raise the pots on feet or a table. And a basket that stops flowering in midsummer is usually hungry or root-bound: feed it, cut it back by a third, and it will usually come back into flower within a fortnight.
Frequently asked questions
What flowers grow best in containers?
Petunias, geraniums, marigolds, calibrachoa, trailing lobelia and verbena flower for months in pots and baskets. Dahlias suit a large tub, and tulips and daffodils suit pots in spring.
How often should I water container flowers?
Check daily in summer: water deeply when the top inch of mix is dry. Hanging baskets may need water twice a day in hot weather, while a large tub may need water every day or two.
Why do my petunias stop flowering in midsummer?
Usually they are hungry or leggy. Feed every two weeks, deadhead regularly, and cut a leggy plant back by a third — it will come back into flower within a fortnight.
What is the thriller-filler-spiller pattern?
A tall upright flower in the centre, mounding flowers around it, and trailing flowers spilling over the edge. It is the simplest way to plant a container that looks full and balanced.
Can I grow tulips in a pot?
Yes — plant them in autumn, in a pot with drainage, at a depth of two or three times the bulb's height, and put the pot where you will see it in spring.
Container flowers are a garden you can carry: a pot by the door, a basket by the window, a tub on the patio. Choose the right pot, fill it with good compost, water and feed it regularly, and deadhead as you go. For the individual flowers, see the growing guides, including petunias and dahlias, and plan your displays with the garden planner.