Vegetables in containers

Suitable for...

The following vegetables lend themselves well to container cultivation:

Beetroot, Broad beans, Carrots, Dwarf French beans, Herbs, Peas, Potatoes, Radishes, Rocket, Runner beans, Chillies & Peppers, Salad leaves, Salad onions, Salad turnips, Tomatoes. 

When to grow vegetables in containers

Timings vary depending on the crop, but the main growing season is from early spring to autumn. 

How to grow vegetables in containers

Container choice

• Pots, troughs and grow-bags can all be used to allow gardeners without time or room for a vegetable plot to grow fresh, tasty produce
• Container-grown vegetables can be started off in a glasshouse, conservatory or porch for earlier crops
• Smaller containers can result in a lack of moisture and nutrients for plant roots. Aim for containers with a depth and width of at least 45cm (18in), otherwise frequent watering and feeding will be needed

Compost choice

• Use sterile proprietary potting composts to obtain best results
• The soil-based compost John Innes No 3 is especially easy to manage, but other composts, including peat-free varieties, are also suitable
• Compost in grow-bags is often both good value and reasonable quality
• Home made mixtures of two parts soil and one part well rotted organic matter fortified with extra fertiliser can be an economical substitute, but home-made mixtures are not sterile, so may pose a risk for pest and disease problems
• Organic growers who wish to avoid fertiliser use can get good results from mixing well-rotted manure into the potting compost in the lower half of their containers – 20 percent by volume should be sufficient

Further care

Aftercare should involve provision of a constant water supply, but take care to avoid prolonged waterlogging. A feed of general-purpose liquid fertiliser can be applied every two weeks. If frost is likely, cover the plants with horticultural fleece and move the pots to a warm, sheltered spot.

Crop Selection

Rewarding vegetable crops for containers include:

• Beetroot: sow in March at 10cm (4in) spacings. The young leaves can be used as ‘spinach’. Follow these with quick growing crops of late summer salads. See AGM beetroot 
• Broad beans: sow from February at 20cm (8in) spacings. The tops can be pinched out to reduce blackfly attacks and also for use as ‘greens’. The broad beans can be followed in June or July with beetroot for late summer crops. See AGM beans and peas 
• Carrots: sow Nantes or Amsterdam cultivars from February for June harvesting. Thin seedlings to 8cm (3in) between plants. Cover the containers with fleece from April onwards to exclude carrot fly. After the carrots, sow French beans to gather in September. See AGM carrots 
• Herbs: parsley, for example, can be sown in March for harvesting from June; coriander is also an attractive and popular crop. Basil is another great herb for pots. Repeat crops can be sown for late summer harvest
• Lettuces: mini lettuces such as ‘Little Gem’ and ‘Tom Thumb’, spaced at 15cm (6in), can be sown from January for June harvesting. Follow the lettuces with leeks for winter harvesting. See AGM lettuces 
• Peas: sow ‘mange-tout’ cultivars with edible pods from March; plant them out at 15cm (6in) spacings; harvest in June and follow with salad leaves for late summer. See AGM beans and peas  
• Potatoes: plant early cultivars from March with one tuber for every 30cm of pot diameter. See AGM potatoes 
• Salad leaves: sow from February aiming for 5cm (2in) between plants. Rocket, coriander, lettuce, chicory and spinach are tasty choices. Harvest by pinching off the top few salad leaves, leaving a stump to re-sprout for follow-on crops
• Salad onions: sow from February with 3cm (1¼in) between plants. Pull them up when they get big enough. By July, you should be able to re-sow with finger carrots for bunches of baby carrots in October. See AGM onions 
• Spinach: sow from February aiming for 10cm (4in) between plants. Spinach quickly runs to seed, so follow it with courgettes in June for late summer fruits. See AGM spinach

Links

AGM vegetables
RHS Grow Your Own

Problems

Growing vegetables in containers are generally quite easy with the main problems being;

• Drying out is a common problem, so ensure a regular water supply, avoiding floods and droughts
• Lack of root space can be a problem in small containers, and may result in wilting and symptoms of nutrient deficiency