Dahlia bulbs are Fun to Grow
And just to impress you with the botany of this plant, you will be hard pressed to find original dahlia bulbs because after nearly 200 years of selecting and hybridizing, we have hundreds of plants to choose from – but you’d have to look very hard for the original species.
Dahlia bulbs are not winter hardy and cannot tolerate frost. The first frost sees them go black very fast. Only plant outdoors in the spring after the last spring night frost. Here are more instructions on planting dahlias
Once you've grown them, you may find it useful to read about storing dahlia bulbs
Get More Flowers By Doing This
To get a jump on spring, some gardeners pot up their dahlia bulbs indoors 6 weeks before they want to plant them outdoors. Pinch off the main growing tips three weeks after you plant to increase the bushiness of the growing plant. YouÂ’ll see many more stems develop and tons more flowers. And these flowers should be deadheaded (cut off the flower and its stem) as this seems to make the tuber produce more flowers. (and we all want more flowers donÂ’t we?)
Plant Details
Flower colour: nearly all colours are available
Flowering period: July - October
Planting depth to base of bulbs: 5 - 7 cm above the top of the tuber
Spacing between bulbs: depends on the type of dahlia (average is 5-7 per m²
Type of bulb: tuberous root
Light requirements: sunny, the more the better. Dahlia bulbs need sunshine by 10 am to produce a full crop of flowers.
Landscaping With Dahlia bulbs
Dahlia are long blooming plants so they combine very well in perennial borders. Their exotic looking flowers and brilliant colors act to carry the perennial border over any non-flowering periods. ThereÂ’s a color and size to match almost every garden design. See below.
Container Varieties
The smaller dahlia bulbs are excellent container plants and do very well in mixed pots. There they bloom almost all summer requiring only weekly feeding to keep them going. Look for Mignon, Top-Mix, Dahlietta, Dahlstar, Dahlinova, and Gallery dahlias, as well as all other low-growing dahlias with compact habits to really brighten up your balcony garden or patio garden.
Dahlia Classes
Dahlias are classed in the following way. It helps to understand the classes so you know what youÂ’re getting when you order or pick up a tuber at the store. As an aside, dahlia bulbs are not really bulbs but are tubers (treat them like you would a potato tuber for success).
Division 1: Single-flowering
Distinguishing characteristics: one ring of florets, central group of disc florets. height is 40 - 60 cm.
Division 2: Anemone-flowering (pictured)
Distinguishing characteristics: one or more rings of florets, central group of tubular florets. The height is 60 - 90 cm.
Division 3: Colarette
Distinguishing characteristics: one outer ring of flat florets and an inner ring of collar florets, central group of disc florets. The height is 75 - 120 cm.
Division 4: Water-lily
Distinguishing characteristics: fully double, flattened shape, florets are flat with slightly curved margins. The height can be 120 cm.
Division 5: Decorative
Distinguishing characteristics: fully double, flat florets are broad and blunt-ended. The height 150 cm.
Division 6: Ball
Distinguishing characteristics: fully double, ball shaped (often flat), florets are blunt or round ended. The height 120 cm.
Division 7: Pompon
Distinguishing characteristics: fully double, globe shaped, involute (rolled inward) florets are blunt or round ended. The height is 80 - 120 cm.
Division 8: Cactus
Distinguishing characteristics: fully double, involute (rolled inward) florets are narrow and pointed, height is about 150 cm.
Division 9: Semi-Cactus
Distinguishing characteristics: fully double, pointed florets are involute for half their length or less, height to 150 cm.
Division 10: Peony-flowering
Distinguishing characteristics: fully double, florets are round ended, height is 100 cm.
Division 11: Mignon
Distinguishing characteristics: small flowers (6 - 10 cm). Very suitable for pots and containers. The height is about 50 cm.
Division 12: Topmix
Distinguishing characteristics: small flowers (3 - 5 cm). Very suitable for pots and containers. The height is about 35 cm.
Dahlia bulbs can be grown as potted plants and these receiving a great deal of interest; you can now grow these the same way you can buy potted chrysanthemums. You can also order these dahlias from specialty growers and do the same thing – grow them in pots for your balcony or patio.
Three new groups can be distinguished:
Dahlianova types: Double flowering varieties are available in almost every color. No taller than 8 -12 inches (20-30 cm). The tubers are denser and smaller than those in the normal assortment. A few examples: Dahlinova 'Arizona,' Dahlinova 'Ohio,' Dahlinova'Virginia.'
Gallery series: This series contains cactus and decorative varieties that are no taller than 12 - 14 inches (30-35 cm). A few examples: Gallery 'Rembrandt,' Gallery 'Art Deco,' Gallery 'Leonardo.' YouÂ’ll often see the Gallery series in garden centres sold as annuals.
Impression selection: These are colarette dahlias and primarily suitable for bedding and for use on balconies and patios. Depending on the variety, height can range from 12 - 20 inches (30 to 50 cm). Some examples: Impression 'Festivo,' Impression 'Fortuna,' Impression 'Fuego.' These plants will regularly be found in garden centres in packs for general bedding use.
Click here to ask Doug about dahlia bulbs.
