Lobelia erinus “Trailing Lobelia”
Care Guide

Lobelia erinus are used in the gardening world as ground cover, in hanging baskets, in any containers or window boxes to create a dazzling display.

Lobelia erinus is a hugely popular annual plant that blooms continuously throughout the summer, into autumn, until there is a severe frost.

It is also referred to as lobelia or trailing lobelia, they have delicate blue, violet, pink, or white flowers add a touch of elegance to any garden. Here are some tips and tricks for sowing, transplanting, and caring for Lobelia erinus. Be aware that even though the Lobelia erinus has the common name of Lobelia there are over 400 species in the genus Lobelia.

trailing lobelia in pot
Trailing Lobelia in a large terracotta pot.

Sowing Lobelia erinus

It is best to sow Lobelia erinus seeds indoors about 8-10 weeks before the last frost date in seed trays or pots.. 

In a tray or pot, fill it with seed compost or seed-starting mix with good drainage, and sprinkle the seeds over it. You do not have to cover the seeds since they need light to germinate.

Germination typically takes 7-14 days in seed trays or pots when kept in a warm place (around 18-20°C). 

It is also possible to direct sow them in a hanging basket or a flower bed after the chance of frost has passed, and then thin them out as necessary.

Transplanting Lobelia erinus

After all dangers of frost are past, and the young lobelia plants have developed several sets of true leaves, they can be transplanted into the garden or into hanging baskets. Lobelia erinus prefers a partially shaded spot with good air circulation. If you’re planting them in hanging baskets, please make sure that the baskets have drainage holes so that it does not become waterlogged. Water them well after planting, and mulch the soil to help keep moisture in.

Trailing Lobelia in a row of hanging baskets.
Trailing Lobelia in a row, used in hanging baskets.

Watering Your Lobelia erinus

It is important to water Lobelia erinus frequently so that the soil remains evenly moist and not waterlogged. Lobelia erinus prefers consistent water, so keep it hydrated during dry periods. Deadhead them regularly to make sure that the plant produces more flowers. It will also grow bushier and produce more flowers if the tips are pinched back.

trailing lobelia white
White trailing Lobelia

Pest and Disease:

Lobelia seedlings are affected by a fungal disease known as dumping off. As a result, the stems rot. To avoid this problem, you should improve the air circulation, water the plants from the bottom and avoid wetting the foliage. Also avoid sudden changes in temperature.

Lobelia is generally pest and disease free, but watch out for slugs, snails and whiteflies. They can be controlled by using slug and snail baits or by picking them off by hand. Whiteflies can be controlled by using insecticidal soap or neem oil.

Propagation:

Lobelia erinus cannot be propagated, due to the fact it just wouldn’t survive the cold winters in the UK, but luckily you can let some of the flowers go to seed and then collect the seeds so you have some that you can sow next year.

Michael

Michael is the founder of HelloGardening and an accomplished gardener who has a deep love for horticulture and design. He has honed his gardening skills over several years and has completed several long-distance courses around gardening.

Furthermore, Michael has a degree in Urban Design, which has equipped him with a broad knowledge of the principles and practices involved in designing and planning urban spaces.