All containers must be suitable for their purpose. They must fit the plant and they must contain sufficient compost for that plant to flourish. They must be strong enough to withstand the elements. They must also have adequate drainage to allow surplus water to drain away when the plants are watered.
Drainage. Almost all garden containers that you can purchase will have proper drainage holes already in place but if they don’t you will have to make holes in the bottom. The same goes if you have made the containers yourself. Make sure that there are enough drainage holes and if you are lining the container with polythene see that there are holes in the polythene that align with the holes in the bottom of the container.
The correct hardcore. Prepared containers must include sufficient hardcore, crocks, broken pottery or small stones, in the bottom to keep the compost aerated and ensure that it does not run out of the drainage holes when the container is watered.
Make sure that any hardcore material used in the bottom of a pot of ericaceous compost does not contain any lime. For example, limestone chippings and old mortar are obvious sources of lime and should be avoided.
Cleaning. Garden containers should be cleaned after use to prevent the spread of disease. Scrub them thoroughly to remove all dirt and if necessary soak them overnight in soapy water. Ensure that they are completely dry before filling and re-using. Keep your garden nice and tidy!
Wooden containers. These need to be treated with a preservative recommended for horticultural use before they are first planted. Make sure that you use one this is safe with plants and follow the instructions on the label. Preservatives such as creosote should be avoided at all costs as they will kill any plants.
You can also extend the life of a wooden container by lining it with plastic. Make holes in the bottom of the plastic for drainage and then fix it to the sides of the container with a staple gun.
It is also a good idea to line the sides of any copper, iron or lead containers that you are using in order to prevent the metallic elements of the container leaching into the compost which might affect the plants.
Allow air to circulate. Also raise all garden containers off the ground slightly, in order to promote drainage and allow air to circulate, by putting them on wooden chocks or special clay feet. This is a particularly important consideration for wooden garden containers because if they are allowed to sit permanently in damp they will gradually rot.