Lobelia siphilitica Clear Blue - seeds
Lobelia siphilitica Clear Blue - seeds
Lobelia siphilitica Clear Blue
More information
Back-to-school special offer!
Get €10 off for every €50 you spend! And get up to €40 off on a single order.
How does it work?
1. Shop your favourites
Add your favourite plants to your basket. For every €50 you spend (excluding delivery charges, store credit and the plastic-free option), you’ll receive a €10 voucher.
€50 spent = €10 voucher
€100 spent = €20 voucher
€150 spent = €30 voucher
€200 spent = €40 voucher
2. Place your order
Once your basket reaches one of the spending thresholds, place your order. You can even choose your delivery date!
3. Receive your voucher
As soon as your order has been shipped, you’ll receive an email containing your personal voucher code and its value.
4. Use it on your next order
Your voucher is valid for 90 days from the date you receive it. It can be used once only, on a new order worth at least the value of the voucher, excluding delivery charges.
Please note: Vouchers can be combined with other offers, but cannot be split or refunded.
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.
Would this plant suit 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).
The flowering period indicated on our website applies to countries and regions located in USDA zone 8 (France, the United Kingdom, Ireland, the Netherlands, etc.)
It will vary according to where you live:- In zones 9 to 10 (Italy, Spain, Greece, etc.), flowering will occur about 2 to 4 weeks earlier.
- In zones 6 to 7 (Germany, Poland, Slovenia, and lower mountainous regions), flowering will be delayed by 2 to 3 weeks.
- In zone 5 (Central Europe, Scandinavia), blooming will be delayed by 3 to 5 weeks.
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 planting period indicated on our website applies to countries and regions located in USDA zone 8 (France, United Kingdom, Ireland, Netherlands).
It will vary according to where you live:
- In Mediterranean zones (Marseille, Madrid, Milan, etc.), autumn and winter are the best planting periods.
- In continental zones (Strasbourg, Munich, Vienna, etc.), delay planting by 2 to 3 weeks in spring and bring it forward by 2 to 4 weeks in autumn.
- In mountainous regions (the Alps, Pyrenees, Carpathians, etc.), it is best to plant in late spring (May-June) or late summer (August-September).
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.