Tall spikes of deep maroon foliage topped by glowing scarlet blooms bring a welcome splash of late summer colour, when many flowers have already faded. This exotic looking, short lived perennial is ideal for filling gaps in damp borders, and looks spectacular planted beside ponds and streams.
When lobelia plants are well grown and all risk of frost has passed, acclimatise them to outdoor conditions over 7 to 10 days. Transplant outdoors in a sheltered position in sun or semi-shade on reliably moist, fertile soil. Lobelia cardinalis copes well with boggy soils and can be planted at the edge of ponds and streams.
Cut back old lobelia foliage in autumn and apply a dry mulch of bark chips or straw to protect the crown of the plant during winter. Lobelia cardinalis is a short lived perennial - divide it every 2 years in spring to maintain its vigour. Caution: irritant to skin and eyes.
Cottage gardens, water garden, wildlife gardens, exotic garden