Lobelia Plant Care – Floralelle

fact sheet

flower colour


Flowering time (month)

flower form

leaf colour

leaf shape

Ornamental or utility value

flower decoration
picturesque growth


flower beds

growth characteristics


soil type

soil moisture

moderately humid to humid

lime tolerance

nutritional requirements


garden style

flower garden
roof garden
pot garden

Male faithful (Lobelia erinus), also called Blue Lobelie or Lobelie for short, belongs to the bellflower family (Campanulaceae) and is originally native to the Cape region of South Africa. The lush perennial shrub has turned into a popular balcony flower for us.

The habit of the maleertreus is very compact and dense. There are upright and hanging varieties, which are usually all cultivated by us for one year. The upright Lobelia varieties grow between 15 and 35 centimetres high, the hanging ones develop shoots that can grow up to one metre long.

The leaves of the Lobelie are alternate, lanceolate and about two to three centimetres long. Their colour ranges from green to dark green.

Male faithful forms a multiplicity of small blooms and blooms from May into September. The flowers are zygomorphic, i.e. they consist of two completely mirror-like halves. They are mostly kept in a more or less pronounced blue shade, but they are also available in violet and with or without a white eye in the middle.

After flowering, small capsule fruits develop which, as soon as they open, release the seeds.

Although male faithful also thrives in semi-shade, the more sun, the more flowers. Hanging Lobelia varieties are best used in hanging baskets, but can also be used for planting under tall stems. Upright growing male loyal varieties are better kept in balcony boxes, pots or bowls.

You can use commercially available humus-rich potting soil as substrate for your lobelia.

Always keep the men’s clothing evenly moist. Especially in pot culture its substrate should never dry out completely. To prevent waterlogging, we recommend placing a drainage layer of expanded clay or similar in the bottom of the plant container.

The multiflowered plants have a high nutrient requirement, which you should meet with regular fertilization. Fertilise the men’s crop every two weeks with a little low-dose fertiliser over the watering water. Important: Only use fertilizers with a low nitrogen content. Although nitrogen promotes plant growth, it also inhibits flower formation.

Other care
To ensure that the flowering period really lasts until autumn, the male flowers are cut back by a third after the first main flowering at the end of July.

A hibernation is possible only with very few men-loyal-types. The ‘Richardii’ variety, for example, can be brought into a bright winter quarter warm between 10 and 15 degrees Celsius before the first frosts. Water the plant moderately there and put it outside again after the ice saints. However, it usually makes more sense to collect the seeds in autumn and sow the Lobelie again next spring.

The most common place for men to be faithful is on the balcony or terrace. Proven planting partners are nasturtium or geraniums. Tone-in-tone plants with, for example, blue daisies ensure a continuous sea of flowers. In the garden, lobelia is often used as ground cover, for bed borders or sunny borders.

Numerous breeds and varieties of maleertreus are available on the market. They differ both in the colour of the flowers and in their growth habit. Upright and with a growth height of about 10 centimeters rather small, are for example:
Blue pearl’: bright blue flowers
Cambridge Blue’: light blue flowers
Kaiser Wilhelm’: light green foliage and cornflower blue flowers
Rosamunde’: intense red flowers with white eye
‘Snowball’ and ‘Regatta White’: pure white
Pumila Splendens’: dark blue with white eye

The male faithful varieties grow hanging:
Cascade Mix’: a mixture of blue, white and purple flowers; the shoots grow up to 40 centimetres long.
Sapphire’: dark blue flowers with a white eye; the shoots grow up to 50 centimetres long.
Richardii’: flowers in light blue; the shoots are up to 100 centimetres long

Male loyalty is increased by sowing. Sow the seeds from March under glass at 16 to 18 degrees Celsius. Since they are light buckets, the seeds are only covered with a thin layer of substrate. The seedlings are then pricked into individual groups to form small compact plants. From May – as soon as the ice saints are over – the plants can move outside and to their final place on the balcony, terrace or in the garden. The lobelia variety ‘Richardii’ can only be propagated with cuttings. Cut these in November.

Diseases and pests
Attention: Faithful to men is susceptible to grey mould (grey rot). With the right choice of location (nice and airy) and suitable substrate (low in nitrogen and permeable) you can prevent the fungal disease – but there is no one hundred percent protection. Therefore, check regularly for infestation and remove the affected parts of the plant immediately. Especially in balcony boxes there is a high risk of infection.






Don Burke

I am Don Burke, one of the authors at My Garden Guide.  I am a horticulturist that cultivates, grows, and cares for plants, ranging from shrubs and fruits to flowers. I do it in my own garden and in my nursery. I show you how to take care of your garden and how to perform garden landscaping in an easy way, step by step.I am originally from Sydney and I wrote in local magazines. Later on, I have decided, more than two decades ago, to create my own blog. My area of specialization is related to orchid care, succulent care, and the study of the substrate and the soil. Therefore, you will see many articles dedicated to these disciplines. I also provide advice about how to improve the landscape design of your garden.

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