You will need plants, a clean container, draining crocks (broken clay pots are the traditional favourites, but broken up polystyrene trays are also ideal) and good quality compost. (Some composts are specially formulated for containers and contain slow release fertiliser and water retaining granules.)
How many plants do I need?
Container plants are generally more densely planted than those in borders - plan on 6-8 plants for a 30-40cm container.
What design should I follow?
This is where the fun begins! Plant with single varieties for impact (Fanfare New Guinea Impatiens would be a superb choice) or go for a traditional look with a larger plant such as a bush fuchsia, geranium or osteospermum as a centrepiece surrounded by smaller trailing or lax plants. Go for contrasting or harmonising colours, pretty pastels or flamboyant brights - your imagination is the limit!
How do I plant my container?
Place the crocks at the bottom and fill the container with compost. Water your plants well before removing them from their pots. Arrange them in the container to check the spacing before planting anything. When you are happy with the design, start with any central plants and continue outwards. When all your plants are in, fill the container with more compost to a couple of finger widths below the rim, ensuring all plants are planted at the level they were originally. Water well and keep in a sheltered spot whilst the plants establish. Bring in at night until there is no risk of frost.