Dahlias are magnificent flowers.
A short list of Dahlia facts
Name – Dahlia
Family – Asteraceae
Type – bulb plant
Height – 8 to 60 inches (20 to 150 cm) depending on the variety
Exposure – full sun
Soil – enriched ordinary soil
Flowering – June to October
Here is the advice on how to care for them to produce magnificent dahlias.
It is important to plant your dahlia correctly, since this step is crucial to your plant’s growth and flowering.
Planting dahlia bulbs
Preparing cuttings is the simplest, fastest, and most common planting technique to multiply your beautiful dahlia flowers.
- Dahlia bulbs are best planted during the months of April and May, when the last frosts are past.
- Dahlia prefers rather rich and well drained soil.
- Plant them about 2 to 4 inches (5 to 10 cm) deep, and space the bulbs 30 to 40 inches (80 to 100 cm) apart, because dahlia requires sunlight and likes having space to spread out!
If you feel that the soil in your garden is rather poor, enrich it upon planting with organic soil conditioner or compost.
It is perfectly possible to sow dahlias from seed, but this technique requires an extensive know-how that only true experts can master.
- To sow, start with sowing in a tray in early March, repot in April and transplant in the ground in May.
- Propagating through tuber division in spring.
Pruning and caring for dahlias
- Remove wilted flowers regularly (deadheading).
- Once stems are completely wilted, cut them as short as you can.
- Dahlia plants can resist freezing temperatures down to around 14° to 23°F (-5 to 10°C).
In winter, it is important to protect the base of your plants with plant-based mulch.
- If you fear particularly strong freezing:
At the beginning of winter, bring the tubers indoors when the first frost spells hit, and keep them in a dark, dry place until the following spring.
Dahlias are quite resilient, but appreciate being watered during extended dry spells.
Check that dahlia bulbs never get flooded or stand in stagnating water, since this would make them rot.
Well-drained soil guarantees that this kind of mishap doesn’t happen.
- Water dahlia without wetting its leaves. Doing this will help avoid any risk of disease.
- Water preferably in the evening to reduce evaporation and also save water.
How to prolong dahlia blooms from summer to fall
Dahlia blooms can be extended even until after summer is over, sometimes even until the end of October.
- Add flower plant fertilizer once a week until the end of the blooming season.
- Remove wilted flowers regularly to avoid draining your dahlia and to spur appearance of new flowers.
Dahlia in winter
Although dahlia can spend the winter in the ground in mild-wintered areas, it can’t survive strong frost spells.
If you live in an area where the weather frequently drops below 23°F (-5°C), bringing your bulbs indoors before it freezes is your only hope.
- Wait for leaves to wither completely, and then cut them 4 inches (10 cm) above ground level.
- Pull out the rhizomes and let them dry off.
- Clean them with a brush.
- Keep them in a cool, dry and dark place.
- Replant them outdoors when the last frosts are past, in spring.
In other regions, protect your tubers with dead leaf mulch for instance.
Learn more about dahlia
There are cactus and semi-cactus dahlia varieties, pompom or ball dahlias, ornamental dahlias, and collarette dahlias, that provide for dazzlingly varied shapes and colors.
This is a plant that comes in a wide variety of blooms!
Its long flower-bearing stems stand tall and true, and produce beautiful flowers with many colors.
- Dahlia imperialis, tall tree dahlias
- Red label dahlias to help you choose, an honorific classification was invented
Interesting dahlia cultivars
Among the many interesting dahlia cultivars, we’ve admired the following: ‘Aspen’, ‘Café au lait’, ‘Berliner kleene’, ‘Margareth kleene’, ‘Arabian night’, ‘bluesette’, ‘Deuil du roi Albert’, ‘Bishop of Llandaff’, dahlia ‘Bonesta’, dahlia ‘Chantal’…
There are many more!
Smart tip about dahlia
When you’re planting it, add manure to the soil or any type of time-release organic fertilizer to enhance growth and blooming.
Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Rainbow-colored Wizard of Oz dahlia by Ray under © CC BY 2.0
Black leaved dahlia by Gabriele Lässer ★ under Pixabay license
Dahlia bush by Simon Cope under © CC BY-SA 2.0
Red and white dahlia by Alex Malev under © CC BY-SA 2.0