Grow your own food

No garden, no problem: Your guide to growing edibles in containers

Growing food in containers is easy, practical and anyone can do it — with a little guidance

13 February 2022 - 00:02
By Jane Griffiths
Mint and lemon thyme in terracotta pots.
Image: Keith Knowlton Mint and lemon thyme in terracotta pots.

For city dwellers, container gardens make good use of limited space and produce a surprisingly large harvest when fed and watered correctly. Various options are available, including wooden boxes, colourful pots and metal barrels. You don’t need to spend a fortune as many items can be recycled and adapted — just make sure they have drainage holes.

Containers have other advantages:

  • They are ideal for those with mobility or back problems.
  • Containers can be moved to take advantage of the sun and to provide protection from frost.
  • When renting, you can move your garden with you.
A Thai lime tree and herbs in various sized pots.
Image: Jane Griffiths and Keith Knowlton A Thai lime tree and herbs in various sized pots.

SIZE MATTERS

Match the right container with the right plants. For robust vegetables (tomatoes, eggplant, squash and fruit trees) choose wide, deep containers. Shallow-rooted vegetables (lettuces, spring onions, spinach and many herbs) will grow in smaller ones. Plants with long tap roots (carrots, radishes, beetroot and parsley) need a container at least 30cm-35cm deep.

WHAT TO GROW

An abundance of edible plants are suitable. Companion planting also works in containers, so don’t forget to include companion herbs and edible flowers.

Tomatoes: Cherry tomatoes are easy to grow and provide steady harvests over a few months. Include a tall sturdy tripod in the centre for support.

Eggplants: Choose smaller-fruited varieties such as the Patio baby or Thai round.

Squash: Bush varieties of zucchini and patty pan are suitable for large containers. For rambling gem squash or miniature pumpkin, position the container against a wall with a tall trellis.

Greens: An abundance of greens grow well in containers, including lettuce, spinach, Swiss Chard, Asian greens and kale.

Beans: Bush and climbing beans do well; provide tall support for climbers.

Herbs: Almost all herbs happily grow in containers. Combine ones with similar growing requirements, such as thyme, oregano and marjoram.

Fruit: Citrus trees do well as long as they’re fed regularly. Small varieties of fig and pomegranate are also good for pots.

Planting up herb containers.
Image: Jane Griffiths and Keith Knowlton Planting up herb containers.

GROWING MEDIUM

A growing medium’s functions are to provide water, nutrients and support for plants’ roots. It needs to drain so roots don’t sit in wet soil, but also needs to retain sufficient moisture. Using just compost or digging up some garden soil won’t produce happy plants. A good recipe includes a mixture of:

  • 1 part pre-soaked coco peat;
  • 2 to 3 parts sieved fertile compost;
  • ½ part topsoil, to provide nutrients, density and natural organisms;
  • A few scoops of well-rotted manure; and
  • Slow-release organic fertiliser, applied according to the packet instructions. In deep containers, only add this to the top third.

Maintenance

Container plants need to be fed regularly as the nutrients are washed out more quickly. Use a dry organic fertiliser every three months and a liquid organic fertiliser every month.

Containers also dry out quickly and need to be watered more often than plants in the ground. Get into the habit of checking regularly. Installing an irrigation system, such as drip pipes wound through the boxes, will ensure you don’t kill your plants.

Companion planting also applies to containers.
Image: Jane Griffiths and Keith Knowlton Companion planting also applies to containers.
Herbs planted in recycled tins.
Image: Jane Griffiths and Keith Knowlton Herbs planted in recycled tins.

CONTAINER TIPS

• If the container is large and you plan to move it, put wheels underneath before filling.

• Create varying heights by using different size containers or by raising them up on bricks and blocks of wood. This helps increase airflow, reducing disease.

• When using wooden boxes, place them on bricks so water drains away.

• Adding stones to the bottom of containers doesn't increase drainage — it just makes them heavier and reduces the amount of growing medium. Rather add a layer of recycled sponges over the drainage holes.

• Griffiths is the author of five popular vegetable gardening books, including her latest release, Jane’s delicious Superfoods for Super Health. Visit janesdeliciousshop.co.za