Lobelia siphilitica Clear Blue - seeds
Lobelia siphilitica Clear Blue - seeds
Lobelia siphilitica Clear Blue
Special offer!
Receive a €20 voucher for any order over €90 (excluding delivery costs, credit notes, and plastic-free options)!
1- Add your favorite plants to your cart.
2- Once you have reached €90, confirm your order (you can even choose the delivery date!).
3- As soon as your order is shipped, you will receive an email containing your voucher code, valid for 3 months (90 days).
Your voucher is unique and can only be used once, for any order with a minimum value of €20, excluding delivery costs.
Can be combined with other current offers, non-divisible and non-refundable.
Why not try an alternative variety in stock?
View all →
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
Available in 1 sizes
This plant carries a 6 months recovery warranty
More information
We guarantee the quality of our plants for a full growing cycle, and will replace at our expense any plant that fails to recover under normal climatic and planting conditions.
Does this plant fit my garden?
Set up your Plantfit profile →
Description
Lobelia siphilitaca 'Clear Blue' is a form of syphilitic lobelia or giant lobelia selected for its light blue, fresh, and bright flowers. It is a charming, floriferous perennial that thrives in moist to wet soil, sought after by pollinators. Its upright stems bear tall flower spikes from summer to early autumn. This giant lobelia appreciates sunny, non-scorching exposures, as well as not too dense shade. It is a perfect plant for flowering a light and humid understory or the edges of a natural pond.
The 'Clear Blue' syphilitic lobelia is a tall, upright perennial native to North America. It has a fairly fast growth and can reach 60 to 90 cm in height with a spread of 30 cm per stem. It first forms a rosette of large leaves just above the ground, then leafy stems. Its leaves are green, lanceolate and alternate along the stem. Large at the base of the stem, the leaves become smaller as they approach the floral spike. Flowering extends from July-August to October in the form of flower spikes at the top of the stems. The flowers bloom progressively along the spikes. The light blue flowers of this 'Clear Blue' variety have a trumpet shape ending in two cut and outward-curving lips. This perennial tends to be short-lived but self-seeds without becoming invasive if the conditions suit it. Its above-ground, deciduous vegetation dries up in autumn and regrows in spring.
The 'Clear Blue' syphilitic lobelia is hardy (-20°C). Plant this wildflower in large groups of 10 to 20 plants to showcase it best. It thrives in heavy, ordinary, moist to wet soils and tolerates short periods of root submersion. It enjoys sunny exposures with moist soil, as well as shaded exposures in soil that remains simply moist in summer. It is ideal in water gardens, in pond-edge beds, and in understories. Pair it with tall phlox, its brilliant cousin Lobelia cardinalis, Goat's Beard, Rodgersias, and the royal fern.
Attention, seeds suitable for experienced gardeners accustomed to sowing very fine seeds. These seeds are as fine as dust, barely visible to the naked eye.
Flowering
Foliage
Plant habit
Botanical data
Lobelia
siphilitica
Clear Blue
Campanulaceae
North America
Planting and care
Sowing:
Sow indoors from January to April. It is preferable to sow early in the year. Sow thinly on the surface of a special sowing compost kept slightly moist. Mixing the seeds with fine sand allows for a more uniform sowing of very fine seeds. The seeds need cold to germinate: place your sowing tray at 4°C for 2 weeks, then move it to a warm place at a temperature of 18-20°C. Germination takes 15 to 20 days. Transplant the plants when they are large enough to handle into 8 cm pots. Acclimate them gradually to the outdoors (in light shade) and plant them in the garden once the risk of frost has passed. Maintain a spacing of 45 cm between each plant.
Cultivation:
Lobelia syphilitica prefers moist and rich soil, preferably acidic to neutral (non-limestone), clayey and/or humus-bearing. It thrives in non-scorching sun or partial shade. Light shade will enhance the intensity of the flower colour. Ensure that the soil remains moist until the plant is well established. Mulch the soil in summer to conserve moisture. Water if necessary during hot and dry weather. If you allow the plants to produce seeds, you can harvest them in late summer to sow them wherever you like. Spontaneous seedlings are not uncommon, but this plant is never invasive. Moreover, young misplaced plants are very easy to remove.
Sowing period
Intended location
Planting & care advice
-
-
-
-
-
-
-
-
This item has not been reviewed yet - be the first to leave a review about it.
Recently viewed products
Haven't found what you were looking for?
Hardiness is the lowest winter temperature a plant can endure without suffering serious damage or even dying. However, hardiness is affected by location (a sheltered area, such as a patio), protection (winter cover) and soil type (hardiness is improved by well-drained soil).
Photo Sharing Terms & Conditions
In order to encourage gardeners to interact and share their experiences, Promesse de fleurs offers various media enabling content to be uploaded onto its Site - in particular via the ‘Photo sharing’ module.
The User agrees to refrain from:
- Posting any content that is illegal, prejudicial, insulting, racist, inciteful to hatred, revisionist, contrary to public decency, that infringes on privacy or on the privacy rights of third parties, in particular the publicity rights of persons and goods, intellectual property rights, or the right to privacy.
- Submitting content on behalf of a third party;
- Impersonate the identity of a third party and/or publish any personal information about a third party;
In general, the User undertakes to refrain from any unethical behaviour.
All Content (in particular text, comments, files, images, photos, videos, creative works, etc.), which may be subject to property or intellectual property rights, image or other private rights, shall remain the property of the User, subject to the limited rights granted by the terms of the licence granted by Promesse de fleurs as stated below. Users are at liberty to publish or not to publish such Content on the Site, notably via the ‘Photo Sharing’ facility, and accept that this Content shall be made public and freely accessible, notably on the Internet.
Users further acknowledge, undertake to have ,and guarantee that they hold all necessary rights and permissions to publish such material on the Site, in particular with regard to the legislation in force pertaining to any privacy, property, intellectual property, image, or contractual rights, or rights of any other nature. By publishing such Content on the Site, Users acknowledge accepting full liability as publishers of the Content within the meaning of the law, and grant Promesse de fleurs, free of charge, an inclusive, worldwide licence for the said Content for the entire duration of its publication, including all reproduction, representation, up/downloading, displaying, performing, transmission, and storage rights.
Users also grant permission for their name to be linked to the Content and accept that this link may not always be made available.
By engaging in posting material, Users consent to their Content becoming automatically accessible on the Internet, in particular on other sites and/or blogs and/or web pages of the Promesse de fleurs site, including in particular social pages and the Promesse de fleurs catalogue.
Users may secure the removal of entrusted content free of charge by issuing a simple request via our contact form.
In temperate climates, pruning of spring-flowering shrubs (forsythia, spireas, etc.) should be done just after flowering.
Pruning of summer-flowering shrubs (Indian Lilac, Perovskia, etc.) can be done in winter or spring.
In cold regions as well as with frost-sensitive plants, avoid pruning too early when severe frosts may still occur.
The harvesting period indicated on our website applies to countries and regions in USDA zone 8 (France, England, Ireland, the Netherlands).
In colder areas (Scandinavia, Poland, Austria...) fruit and vegetable harvests are likely to be delayed by 3-4 weeks.
In warmer areas (Italy, Spain, Greece, etc.), harvesting will probably take place earlier, depending on weather conditions.
The sowing periods indicated on our website apply to countries and regions within USDA Zone 8 (France, UK, Ireland, Netherlands).
In colder areas (Scandinavia, Poland, Austria...), delay any outdoor sowing by 3-4 weeks, or sow under glass.
In warmer climes (Italy, Spain, Greece, etc.), bring outdoor sowing forward by a few weeks.
The planting period indicated on our website applies to regions in USDA Zone 9a (East Coast and Midlands: Dublin, Wexford, Waterford, Kilkenny, Portlaoise). It will vary depending on where you live:
- On the west coast and in the north-west (Galway, Limerick, Sligo, Donegal, Westport), delay planting by 1 to 2 weeks in spring and bring it forward by 1 to 2 weeks in autumn compared to the dates given, preferably choosing periods without strong winds.
- In the inland hills and plateaus (Wicklow Mountains, Macgillycuddy’s Reeks, Connemara, Killarney), it is best to plant in spring (April–May) or autumn (September–October), avoiding periods of waterlogged soil in winter and strong winds, which pose the main risk to newly planted trees in these areas.
The flowering period indicated on our website applies to regions in USDA Zone 9a, such as the East Coast and Midlands, including Dublin, Wexford, Waterford, Kilkenny and Portlaoise.
This will vary depending on where you live:
- On the west coast and in the northwest (Galway, Limerick, Sligo, Donegal and Westport), it will be delayed by one to two weeks compared to the given dates, due to stronger Atlantic winds and less spring sunshine.
- In the inland hills and plateaus (the Wicklow Mountains, the Macgillycuddy's Reeks, Connemara and Killarney), flowering will be delayed by two to three weeks. Flowering mainly occurs between May and July, with the limiting factors being less frost and more of the excessive humidity, strong winds and lack of sunshine that are characteristic of these areas.