Four of the awarded plants are blue and one is purple. The trial entries were raised from seeds or cuttings and given to the RHS as plug plants. All cultivars were assessed in hanging baskets and terracotta pots filled with non-peat compost.
All the plants were placed outdoors in May and examined by the RHS Floral Trials Assessment Panel every fortnight. They were watered every day and fed at regular intervals throughout the growing season with a liquid feed.
"Lobelias have always been very popular plants for hanging baskets and bedding displays so we felt gardeners would appreciate it if the RHS looked more carefully at which ones would perform best," said RHS director of horticulture Jim Gardiner.
"The trials at RHS Garden Wisley attracted a lot of attention and it was just fantastic to see. Looking down both rows of hanging baskets and terracotta pots full of different blooms just made so many people realise the versatility of lobelias.
"Having different cultivars together meant that gardeners could see the wide range of colours, size and the longevity of the flowers."