Looking at autumn colour, as you may expect, we start with Acers. Bearing in mind, Acers are a large genus of 120 evergreen,deciduous shrubs and trees they do differ considerably, not least in height, anything from 20m to 3 metres. This means it's important to pick the right species of Acer. Illustrated is Acer palmatum which will grow to 10 meters so at some point it needs to come out of the container and into the ground.
Other popular Acers are: Acer palmatum 'Osakazuki' and Acer palmatum Beni Maiko, both of which have stunning red autumn colour. Acer palmatum var. dissectum 'Seiryu' has red/golden foliage, Acer palmatum var. dissectum Dissectum Atropurpureum Group, very red with dissected leaves growing to a large tree.
Ideal for smaller gardens is Acer palmatum ‘Little Princess’ which has yellow and red leaves in the autumn, and compact growth to around 1.5m. The RHS recommends Acer palmatum 'Shin-deshōjō' (AGM) which has lovely serrated leaves with strong red autumn colour, compact so ideal for a container up to 1.5 -2.5m. Another AGM Acer recommended is Acer palmatum 'Orange Dream' which, as the name suggests, has orange autumn colour and grows to around 2.5-4m. Although these Acers are hardy, they will do best in a sheltered spot, south or west facting. Acers are best planted in neutral to acid soil and in partial shade as hot summer sun can scource the leaves, as can cold winter winds.