Dahlia Kelvin Floodlight
Dahlia Kelvin Floodlight
Dahlia Kelvin Floodlight
Dahlia Kelvin Floodlight
Dahlia
Out of the 5 dahlias I purchased, this one is the most spectacular: huge and numerous light yellow flowers!
Pat, 13/08/2025
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.
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
Dahlia 'Kelvin Floodlight' produces enormous double flower heads, 25 to 30cm (10 to 12in) wide. They are bright lemon-yellow, composed of countless slightly turbinate petals resembling small flames. They bloom from summer to autumn on a medium-sized plant clad in dark green foliage. Its extraordinary flowers are wonderful in borders and last a long time in bouquets.
Dahlias belong to the Asteraceae family and are originally from the high plateaus of Mexico. There are currently thousands of horticultural varieties that have conquered gardens worldwide. They are tender perennials with fleshy tubers.
'Kelvin Floodlight' will reach about 1m (3ft) in height and 60cm (24in) in width. It is classified among the giant decorative dahlias, which is a horticultural category defined by the shape and size of the flower. In this group, the coloured ligules of the head are regularly arranged in a spiral, and they can be bent towards the stem or curled, for example. It blooms from July to October. The heads measure 25 to 30cm (10 to 12in) in diameter. The outer ligules are quite large, flexible, and slightly turbinate. They develop a light-yellow colour, while those in the centre are slightly more lemon-yellow. Its habit is bushy and erect, and the highly branched stems are hollow. Its leaves are opposite and pinnately compound, meaning they are divided into 3 or 5 toothed lobes. The leaves and stems are dark green, beautifully enhancing the yellow blooms.
Remove faded flowers to encourage new blooms. You can use cut flowers to make colourful bouquets, combining them with other varieties.
'Kelvin Floodlight' pairs particularly well with orange, blue, and red blooms, especially those of tithonias, anchusa, perennial delphiniums, and scarlet salvias. In borders, it will perfectly match echinaceas, sunflowers, and cleomes, for example. It will also create a unique and elegant mix with sedums and grasses like miscanthus or panicum.
Dahlias are stars of borders and ornamental gardens, confidently accompanying the most beautiful flowers. However, they are also appreciated alongside vegetable plants. In Mexico, this tuberous plant was first cultivated as a root vegetable for consumption. Its poor taste qualities quickly saw it categorised as an ornamental plant. Since then, the interest in their beautiful exuberance has never waned.
Dahlia Kelvin Floodlight in pictures
Plant habit
Flowering
Foliage
Botanical data
Dahlia
Kelvin Floodlight
Asteraceae
Dahlia
Cultivar or hybrid
Planting and care
Dahlia 'Kelvin Floodlight' is easy to grow in all regions. Plant in spring as soon as the last frost has passed. For abundant flowering, plant the tubers in full sun in rich, moist but well-drained soil. Stagnant moisture causes tuber rot. Amend the soil with compost and sand, if necessary. Work the soil deeply and enrich it, for example, with crushed horn or dehydrated blood. Place your tuber and crumble the soil well to fill without air pockets. Cover with about 6cm (2in) of soil. At the end of planting, water once abundantly and then repeat this watering regularly during the first 6 weeks to help with rooting.
Dahlias are sensitive to cold, so they need to be overwintered. Dig the tubers up when the first frost has blackened the foliage. Carefully remove the tubers. Remove as much soil as possible. Let the foliage dry so that the tubers can replenish their reserves. Then cut the stems to 10cm (4in). Spread your bulbs in a box lined with newspaper. Store them in a frost-free, dry, cool, and dark place, such as a garage or attic. In mild regions without frost, or those close to the coast, it is possible to leave them in place. In this case, simply cover the ground with a carpet of leaves or straw for protection.
This tall dahlia, with its hollow stems, is not resistant to wind or heavy rain. You can stake it, but this is not particularly aesthetically pleasing. To remove the need for staking, you can pinch the stems early or remove the axial flower buds to spread out the plant's habit, which will improve its resistance to bad weather. This also channels the flow of sap to a single flower, which will become larger and sturdier.
Planting period
Intended location
Care
Planting & care advice
-
, onOrder confirmed
Reply from on Promesse de fleurs
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.