Planting your pots
Once you've decided on a container, a suitable growing medium is essential for success. The mix (available with or without soil) needs to be porous enough to allow for good drainage and for oxygen to reach plant roots. It must also hold moisture well; most garden soil is not suitable, as it becomes too compacted when wet. Buy the best available (ask a knowledgeable person at a garden centre for advice, as there is usually more than one quality for sale). You can also add compost or composted manure (up to one part compost/manure to three parts potting mix).
While some vegetables can be planted in cool weather, others require warm temperatures. You can sow seeds directly into the containers or plant out seedlings. Thin seedlings once their first true leaves appear. (See chart for what works best for different vegetables.) After planting, water well.
Tip: A solution of liquid seaweed—available at garden centres and nurseries—gives veggies a good start (follow manufacturer's directions).
The leaves of the vegetables should become dark green (unless they're specially coloured) and the plant should grow at a steady rate. If the leaves are pale or discoloured and growth is slow or stunted, then they most likely need fertilizing (see Feeding schedule for more details).
When you check your containers for dryness, also examine plants for disease and pests. Remove any diseased plants and destroy (do not compost). If possible, isolate those that have pests. Aphids are a fairly common problem and can be washed off with a shower of water; repeat every four or five days. Remove dead leaves to discourage mould.
At the end of the season, empty your containers, saving half the soil. (Don't leave filled clay or ceramic pots outside over winter, as they may crack.) Refill your containers the following spring with a combination of fresh potting mix and saved soil.