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Common Name: Dahlia

General Information

Dahlia rosea is a perennial plant that can grow up to 1.50 metres tall.
It is harvested from the wild for local use as a food, medicine and source of materials.

Known Hazards

None known

Botanical References

Range

Southern N. America - Mexico.

Habitat

Pine-oak forests and sandy meadows to 1500 metres[, ].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	1.50 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Requires a deep rich soil and a sunny position[], disliking shade[].
The growing plant is very frost-tender, though the tubers are somewhat hardier. However, these tubers are not reliably hardy if left in the ground over winter in Britain[]. They are best harvested after the foliage is killed off by frost and then stored in a cool but frost-free place over the winter, planting out in April/May[].
A parent of the cultivated garden dahlia[]. There is some confusion over this name, this entry might refer to D. hortensis or D. pinnata[].

Edible Uses

The flower petals are used in salads[].
Root - cooked and used as a vegetable[, ]. A bitter flavour[]. Inedible according to another report[]. A sweet extract of the tuber, called 'dacopa', is used as a beverage or as a flavouring. It is mixed with hot or cold water and sprinkled on ice cream. Its naturally sweet mellow taste is said to combine the characteristics of coffee, tea and chocolate[]. The root is rich in the starch inulin. Whilst not absorbed by the body, this starch can be converted into fructose, a sweetening substance suitable for diabetics to use[, ].

Medicinal

A valuable and much needed drug was extracted from dahlia roots during the first world war[]. No more information was given in the report[].

Other Uses

Yellow and gold dyes are obtained from the flowers and seed heads[].

Propagation

Seed - sow late winter to mid spring in a greenhouse. The seed usually germinates in 1 - 3 weeks at 20°c[]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cuttings of young shoots in early spring. The tubers are usually brought into the greenhouse in late winter in order to encourage early growth and young basal shoots are removed as soon as they are large enough[].
Division. The roots are usually harvested in the autumn. These can be divided into individual tubers when planting out in the spring. Each portion should have a growing point[].