Trailing lobelia (Lobelia erinus) is a versatile little annual, ideal for edging a flower bed or planted in a hanging basket, patio container or window box. The fine-textured, green foliage and mounds of cascading flowers, in vivid shades of electric blue, white and violet, will bloom from spring until the first freeze as long as you provide it with sufficient moisture. Trailing lobelia is a good choice for a butterfly garden, as butterflies are attracted to the bright blooms. Trailing lobelia will thrive with minimal care and is happy in sun or partial shade.
Keep the soil evenly moist and don't allow lobelia to dry out completely. Check trailing lobelia in containers daily during hot weather, as soil in containers will dry out quickly.
Pinch the tips of trailing lobelia when the plants are young. Pinching the tips will encourage the plants to grow full and bushy.
Feed trailing lobelia every four to six weeks during the growing season, using an all-purpose, liquid fertiliser. Alternatively, use a slow-release fertiliser in early spring and again three to four months later.
Prune trailing lobelia down by half if flowering slows and the plants begin to look straggly in midsummer. The plants will soon regrow and bloom.