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Useful Temperate Plants

Dahlia pinnata

Cav.

Asteraceae

+ Synonyms

Bidens variabilis Baill.

Coreopsis crassifolia Sessé & Moc.

Coreopsis georgina Cass.

Dahlia astrantiiflora G.Don

Dahlia mexicana Voss

Dahlia nana Andrews

Dahlia pinnata variabilis (Desf.) Voss

Dahlia purpurea Poir.

Dahlia pusilla Zucc. ex DC.

Dahlia rosea Cav.

Dahlia royleana Knowles & Westc.

Dahlia sambucifolia Salisb.

Dahlia sphondyliifolia Salisb.

Dahlia superflua (DC.) W.T.Aiton

Dahlia variabilis Desf.

Georgia purpurea Spreng.

Georgia rosea (Cav.) Spreng.

Georgina astrantiiflora Sweet

Georgina purpurea Willd.

Georgina rosea (Cav.) Willd.

Georgina superflua DC.

Georgina variabilis Willd.

Common Name: Dahlia

Dahlia pinnata
Flowering plant
Photograph by: Denis Conrado
Creative Commons Attribution-Share Alike 3.0
Dahlia pinnata Dahlia pinnata

General Information

Dahlia pinnata is a herbaceous perennial plant producing a clump of stems up to 1.5 metres tall from a tuberous rootstock.
The plant is sometimes harvested from the wild for local use as a food, medicine and dye. It is a parent of the cultivated Dahlias that are so commonly grown as ornamentals.

Known Hazards

We have no specific information for this species, but the leaves and tubers of several Dahlia species are known to contain phototoxic polyacetylene compounds that can cause skin irritation following repeated handling of the tubers and contact with leaves and light[
293
Title
Poisonous Plants of North Carolina
Publication
 
Author
 
Website
http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm
Publisher
 
Year
0
ISBN
 
Description
An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
].

Botanical References

200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.

Range

Southern N. America - Mexico. Naturalised in much of Central America.

Habitat

Rich damp oak and pine woods, sandy meadows at elevations up to 1,800 metres[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
181
Title
Meet Flora Mexicana.
Publication
 
Author
Pesman. M. W.
Publisher
Dale S. King. Arizona.
Year
1962
ISBN
-
Description
Very readable flora but rather lacking botanically. A few notes on useful plants.
,
260
Title
Conservatory and Indoor Plants Volumes 1 & 2
Publication
 
Author
Phillips. R. & Rix. M.
Publisher
Pan Books, London.
Year
1998
ISBN
0-330-37376-5
Description
Excellent photos of over 1,100 species and cultivars with habits and cultivation details plus a few plant uses. Many species are too tender for outdoors in Britain though there are many that can be grown outside.
].

Properties

Edibility Rating *  *
Medicinal Rating *
Other Uses Rating *  *
HabitPerennial
Height1.00 m
PollinatorsInsects
Cultivation StatusOrnamental, Wild

Cultivation Details

Most Dahlia species in Mexico grow at moderate to higher elevations, typically above 2,100 metres in southern Mexico, where there can be rapid changes in temperature, but no frosts[
2174
Title
The Medicinal and Nutritional Properties of Dahlia spp.
Publication
Journal of Ethnopharmacology, 14 (1985) 75-82
Author
Whitley G.R.
Publisher
 
Year
1985
ISBN
 
Description
 
]. The dahlia’s home area in the volcanic highlands of southern Mexico is hot and dry during the winter months but the rainy season during summer is characterized by afternoon thunderstorms. Also, dahlias are adapted to grow while being bathed in dew from the low hanging clouds[
2174
Title
The Medicinal and Nutritional Properties of Dahlia spp.
Publication
Journal of Ethnopharmacology, 14 (1985) 75-82
Author
Whitley G.R.
Publisher
 
Year
1985
ISBN
 
Description
 
]. The top growth of Dahlia pinnata is very frost-tender, though the tubers are somewhat hardier and can tolerate temperatures down to about -5°c[
260
Title
Conservatory and Indoor Plants Volumes 1 & 2
Publication
 
Author
Phillips. R. & Rix. M.
Publisher
Pan Books, London.
Year
1998
ISBN
0-330-37376-5
Description
Excellent photos of over 1,100 species and cultivars with habits and cultivation details plus a few plant uses. Many species are too tender for outdoors in Britain though there are many that can be grown outside.
].
An easily grown plant so long as the soil does not dry out[
260
Title
Conservatory and Indoor Plants Volumes 1 & 2
Publication
 
Author
Phillips. R. & Rix. M.
Publisher
Pan Books, London.
Year
1998
ISBN
0-330-37376-5
Description
Excellent photos of over 1,100 species and cultivars with habits and cultivation details plus a few plant uses. Many species are too tender for outdoors in Britain though there are many that can be grown outside.
]. It requires a deep rich soil and a sunny position[
164
Title
Growing from Seed. Volume 4.
Publication
 
Author
Bird. R. (Editor)
Publisher
Thompson and Morgan.
Year
1990
ISBN
-
Description
Very readable magazine with lots of information on propagation. A good article on Yuccas, one on Sagebrush (Artemesia spp) and another on Chaerophyllum bulbosum.
], disliking shade[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Dahlia species in the wild are generally found on well-drained hillsides, rough banks and cliffs. The soil is typically a soft, porous and sandy loam with a gravelly subsoil which is often volcanic and mildly acidic[
2174
Title
The Medicinal and Nutritional Properties of Dahlia spp.
Publication
Journal of Ethnopharmacology, 14 (1985) 75-82
Author
Whitley G.R.
Publisher
 
Year
1985
ISBN
 
Description
 
].
Dahlia tubers are worth some experimentation as a root crop either for food or for sugar production since their root sugar content is quite respectable even without artificial selection. For example, up to 15 sweet potato-sized tubers, containing as much as 13% fruit sugar, can be produced by a single plant in one season under optimum conditions. This high sugar content, even among wild dahlias, compares favorably with sugar beets, even though sugar beets have been scientifically selected so that their sugar content has been increased from 7% to 20%. Such scientific breeding could lead to a similar increase in the sugar content of dahlias if they become recognized as a worthwhile agricultural plant[
2174
Title
The Medicinal and Nutritional Properties of Dahlia spp.
Publication
Journal of Ethnopharmacology, 14 (1985) 75-82
Author
Whitley G.R.
Publisher
 
Year
1985
ISBN
 
Description
 
].
In areas where winters are wet, or where temperatures are likely to fall to -5°c or lower, it is best to harvest the tubers after the foliage is killed off by frost and then store them in a cool but frost-free place over the winter, planting them out again in the middle to late spring[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].

Edible Uses

The flower petals are used in salads[
2
Title
Sturtevant's Edible Plants of the World.
Publication
 
Author
Hedrick. U. P.
Publisher
Dover Publications
Year
1972
ISBN
0-486-20459-6
Description
Lots of entries, quite a lot of information in most entries and references.
,
177
Title
Plants for Human Consumption.
Publication
 
Author
Kunkel. G.
Publisher
Koeltz Scientific Books
Year
1984
ISBN
3874292169
Description
An excellent book for the dedicated. A comprehensive listing of Latin names with a brief list of edible parts.
,
301
Title
Cornucopia II
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications, California.
Year
1998
ISBN
0-9628087-2-5
Description
The second edition of an excellent guide to the edible uses of plants, though it does not give any details of cultivation etc.
].

Root - cooked and used as a vegetable[
183
Title
Cornucopia - A Source Book of Edible Plants.
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications
Year
1990
ISBN
0-9628087-0-9
Description
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
]. A bitter flavour[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Inedible according to another report[
2
Title
Sturtevant's Edible Plants of the World.
Publication
 
Author
Hedrick. U. P.
Publisher
Dover Publications
Year
1972
ISBN
0-486-20459-6
Description
Lots of entries, quite a lot of information in most entries and references.
]. 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[
183
Title
Cornucopia - A Source Book of Edible Plants.
Publication
 
Author
Facciola. S.
Publisher
Kampong Publications
Year
1990
ISBN
0-9628087-0-9
Description
Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
]. 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[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
61
Title
A Dictionary of Plants Used by Man.
Publication
 
Author
Usher. G.
Publisher
Constable
Year
1974
ISBN
0094579202
Description
Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
141
Title
Alternative Enterprises for Agriculture in the UK.
Publication
 
Author
Carruthers. S. P. (Editor)
Publisher
Centre for Agricultural Strategy, Univ. of Reading
Year
1986
ISBN
0704909820
Description
Some suggested alternative commercial crops for Britain. Readable. Produced by a University study group.
,
171
Title
Economic Botany.
Publication
 
Author
Hill. A. F.
Publisher
The Maple Press
Year
1952
ISBN
-
Description
Not very comprehensive, but it is quite readable and goes into some detail about the plants it does cover.
].
There are contradictory reports regarding the edibility of Dahlia tubers, ranging from sweet and juicy to extremely bitter, hot and dry tasting and virtually inedible. This could be due to the time the tubers are harvested. If gathered at the beginning of the rainy season - after the inulin had been converted by enzymatic action to produce fruit sugar and before the rapid growth of the tall stalk had depleted the tubers of food - then the tubers would, indeed, have been sweet tasting and juicy. In the second case, if the tubers were gathered late in the growing season or at the beginning of the dry season - before the return of the plants’ food and water resources back into the tubers for storage -then the medicinal constituents of the depleted tubers (especially the skin) could have been expected to give a potent and unpleasant taste. In short, dahlia tubers to be eaten raw immediately should be harvested in the spring, and those intended for medicinal use should be gathered later in the summer when the growing season is well advanced but before the start of the dry season and those intended for baking or storage as food should be gathered well after the start of the dry season when the upper parts of the plant have wilted down in the manner of potato stalks and the tubers are full of inulin, which keeps well[
2174
Title
The Medicinal and Nutritional Properties of Dahlia spp.
Publication
Journal of Ethnopharmacology, 14 (1985) 75-82
Author
Whitley G.R.
Publisher
 
Year
1985
ISBN
 
Description
 
].

Medicinal

A valuable and much needed drug was extracted from dahlia roots during the first world war[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
]. No more information was given in the report[
K
Title
Plants for a Future
Author
Ken Fern
Description
Notes from observations, tasting etc at Plants For A Future and on field trips.
].

Other Uses

Orange, yellow and gold dyes are obtained from the flowers and seed heads[
168
Title
Nature's Colors - Dyes from Plants.
Publication
 
Author
Grae. I.
Publisher
MacMillan Publishing Co. New York.
Year
1974
ISBN
0-02-544950-8
Description
A very good and readable book on dyeing.
,
169
Title
A Weavers Garden
Publication
 
Author
Buchanan. R.
Publisher
McGraw-Hill Contemporary
Year
1987
ISBN
0934026289
Description
Covers all aspects of growing your own clothes, from fibre plants to dyes.
].

Propagation

Seed - sow late winter to mid spring in a greenhouse. The seed usually germinates in 1 - 3 weeks at 20°c[
164
Title
Growing from Seed. Volume 4.
Publication
 
Author
Bird. R. (Editor)
Publisher
Thompson and Morgan.
Year
1990
ISBN
-
Description
Very readable magazine with lots of information on propagation. A good article on Yuccas, one on Sagebrush (Artemesia spp) and another on Chaerophyllum bulbosum.
]. 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[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
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[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2024-12-26. <temperate.theferns.info/plant/Dahlia+pinnata>

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