Dahlia
Dahlia spp.
FIDALGOBLACKY by en.wikipedia (CC-BY-SA-3.0)
Full Sun
Moderate care
Light watering
Tender
H4-H1c
RHS hardiness
-10°C
Minimum temperature
Expected size
Height | Spread | |
---|---|---|
1.8m | Max | 80cm |
20cm | Min | 20cm |
2 years to reach maturity
Flowering
-
spring
-
summer
-
autumn
-
winter
This plant has no fragrance
More images of Dahlia
Dahlia Overview
Dahlias are tuberous herbaceous perennials with usually dark green, toothed, pinnately divided leaves. The showy flowers - often double - are produced in summer and autumn. They are very popular with gardeners, as cut flowers and as show exhibits. Dahlias come in many colours and from tall to dwarf varieties. All need to be planted in a sheltered, sunny position in humus-rich, well-drained soil. They can be treated as perennials or annuals. Originating from the mountainous regions of Mexico and Central America, the Dahlia genus contains around 30 species and over 20,000 cultivars, most of which are derived from D. pinnata and D. coccinea, and divided into groups based on the form of their flower heads. These striking plants will add interest to almost all garden styles and many Dahlia cultivars have earned a coveted 'RHS Award of Garden Merit'. They are also nectar-rich and excellent for attracting bees and other pollinators to your garden - especially the single-flowered varieties, from which it is easier for them to feed.
Common problems with Dahlia
Dahlia have a tendency to be affected by fungal diseases such as powdery mildew or grey mould if planted in poorly draining soil.
How to harvest Dahlia
Flowers can be cut as required for floral arrangements. Best picked in the early morning when the flower contains the most moisture content; use a sharp pair of scissors and take as long a stem as possible.
How to propagate Dahlia
Tubers
Cuttings
In spring take soft-wood cuttings from the shoots appearing from stored tubers.
Division
Lifted clumps of Dahlias can be divided in late winter, ensuring each section has an 'eye' (growing tip).
Seed
Seed from cultivars can be harvested and sown, but flowers are unlikely to come 'true'.
Special features of Dahlia
Attracts useful insects
It attracts beneficial pollinators such as butterflies, bees and moths.
Pot plant
Can be grown in large containers.
Attractive flowers
Autumn colour
Other uses of Dahlia
Grown as bedding plants or for their flower heads, which are good for cutting or exhibition. Suitable for coastal conditions.
Flowers to Sow or Plant Under Cover in March
Sow these seeds and pot up these tubers to get an early start on the year.
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Provided the ground isn't frozen or water-logged, plant these varieties.
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