How to grow shrubs in pots

How to add structure to your patio with a container shrub.

Choosing pots

There is a bewildering amount of containers available in all sorts of shapes, colours and sizes, and made from many materials including metal, stone, plastic and wood. Pick a container that suits the style of your garden and is large enough for the roots of your plant to grow and heavy enough to balance the top-heavy growth. Make sure it has drainage holes and if you go for terracotta, buy good quality, frost-proof pots.

What compost?

Fill pots with John Innes no. 2 compost. It has more nutrients and drains better than general-purpose compost. The compost is also heavier, which will prevent plants from being blown over in the wind. Plants like rhododendrons, azaleas and camellias need special ericaceous compost, ideal for acid-loving plants.

Keep plants well drained

Put a layer of broken terracotta pot or even chunks of polystyrene at the bottom of pots. This will prevent drainage holes from becoming clogged up with compost and soil from falling out. Good drainage stops roots from being damaged by water logging and prevents damage over winter, where frozen water can expand and cause the container to crack. Standing the container on pot feet or even bricks will also help it to drain more effectively.

Containers need regular watering, even after heavy rain, as shrubs have large root systems that take up a lot of water. In hot or dry weather they may need watering once or twice a day.

Feeding

When putting a shrub into a pot, mix in a handful of controlled release fertiliser granules. Depending on the formulation, this will feed the plant for several months. After the food has run out, give plants a boost with liquid feed added to a watering can. Shrubs grown in ericaceous compost can be given a special fertiliser for acid-loving plants.

If your shrub appears to lack vigour or is too large for its pot, repot into a slightly larger container. Remove from old pot, teasing out the roots gently if they're congested. If your plant doesn't need repotting, perk it up annually by removing the top 5-10cm (2in-4in) of compost in the spring, taking care not to damage the roots. Replace with fresh compost that has been mixed with a few controlled release fertiliser granules.

Container grown plants are more at risk from damage than plants growing in the border. Protect plants with fleshy roots, such as camellias and hollies, by wrapping the pots with bubble wrap. Move tender plants into a sheltered place, such as a porch or cold greenhouse, to help get them through the worst of the winter weather.