Growing Plants in Containers

Growing plants in containers is a really simple way to add colour and interest to your garden all year round. Containers can be used to provide dramatic displays or simple flourishes of style. They can also be used to hide unsightly areas in the garden, for example, drainage covers or pipework. Container growing can also have a practical element in allowing you to grow vegetables, which is especially useful if your garden is short on space. Plants in containers do require a little more care than those planted in the ground. The following is a brief guide to the kind of things you need to consider when adding containers to your garden.

Choosing your Pot

Choose containers that are large enough for the eventual size of your plant. If you are planning on growing root vegetables, ensure that the pot is deep enough to accommodate the root. Plastic pots are cheap to buy, while glazed or terracotta pots look more attractive. However, terracotta pots absorb water and this will mean paying closer attention to your watering. You can also line the inside of your terracotta pot with pot with polythene, pierced at the base for drainage.

Planting

Almost any type of plant can be grown in a container. Generally, the bigger the pot and the plant, the easier it is to care for. Soft, fleshy, leafy plants such as tomatoes and fuchsias are more demanding than plants such as pelargoniums (tender geraniums) or lavender. You can choose to plant a feature plant to provide a dramatic focal point in your garden, or you can have a mass of smaller plants to provide a riot of colour.

How to Plant a Container

It is essential that your container has good drainage so place a layer of broken terracotta pot or chunks of polystyrene at the bottom to prevent drainage holes clogging up with compost. 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. You may also want to consider standing the pot on feet to aid drainage. Fill pots with a suitable compost - remember to use ericaceous compost if you are planting acid-loving plants!

Watering

Watering is one of the most vital jobs when growing plants in containers and it is important to get the right amount - too little or too much can cause plants to die

Summer watering

Moisture levels should be checked daily from April to September, increasing to twice daily in hot weather. The container should be watered thoroughly by filling the container to the rim and allowing it to drain. Check the drainage holes for any blockages if the water does not appear to be draining. Pots can also be grouped together for mutual shade to reduce heat stress.

Winter watering

Watering may still be necessary for conifers and other evergreens if they have been moved indoors away from rainfall. Check evergreens and conifers at least weekly and water if needed. Watering is seldom necessary for deciduous or other dormant plants.

Feeding

Summer feeding

From April to the end of August use a general-purpose proprietary liquid feed or a high-nitrogen feed.

Alternatively, add a controlled-release fertiliser at planting time. After late summer feeding is usually suspended until mid-sping; however bedding plants and other short-lived annuals will still benefit from feeding until early autumn. All feed should be applied when the compost is wet to prevent scorching.

Winter feeding

Feeding is not necessary during the winter months.

Re-potting

Plant roots eventually fill containers and this can reduce growth. This is not necessarily a bad thing as slightly stressed plants are often attractive and the slower growth reduces the maintenance needed. However, eventually the plant will need to be moved to a bigger container or the compost refreshed in the same pot, as composts lose their structure over time. Shrubs and trees that stay in a pot for years are especially vulnerable unless re-potted. When moving plants to a larger container re-pot in early spring as soon as they show signs of growth. Gently slide the plant out and tease out the roots - it may be necessary to trim the roots slightly.

If the plant is to be repotted in the same pot then one-third of the compost should be replaced with fresh material.

If plants are not to be repotted apply a top dressing.

Problems

In winter the main problem is frost damage. Extreme temperatures can cause the compost to freeze, which will kill the plant. Containers can be protected with bubble plastic or moved indoors.

Overwatering is the most common cause of loss of container plants so aim to keep the compost moist and avoid situations of extremity - i.e., do not veer from dryness to saturation.

Plants grown in containers suffer from many of the same pests and diseases as when grown in beds and borders. Vine weevil in particular is a common pest of container-grown plants.