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10 Neat Things About Dahlias
by Dorothy Dobbie
by Dorothy Dobbie

The Local Gardener magazines, Ontario Gardener, Manitoba Gardener and Alberta Gardener, are published by Pegasus Publications Inc.

Drawing on her 30 years' experience as a senior executive in the magazine publishing industry, Dorothy launched Manitoba Gardener in 1998, initially running the business out of her home. Two years later, Dorothy's daughter Shauna, living in Ontario, jumped into the fray with Ontario Gardener. And two years after that, they started Alberta Gardener. Visit us at and register for our "Ten Neat things" newsletter. Watch Shaw TV for garden tips and Listen to CJOB for the Gardener Sundays at 9:08

June 2, 2013

1. Food for the soul.

Dahlia tubers are edible. They were eaten by the Aztecs and were brought to Europe as a possible substitute for potatoes, but the indifferent tasting tubers were no match for the brilliant flowers and they soon became food for the soul rather than the body. Apparently older hybrids taste best, some tasting a bit like a spicy apple and others like celery root or even carrots.

2. Oh, those flowers!

Dahlias may be the most spectacular flowers in the world. The dinner plate dahlia can be as much as 14 inches in diameter. They come in almost every colour and colour variant except blue. What some hybridizers call "blue" is really purple or lavender. If you see a photo of a blue dahlia, it has either been treated by Dr. Photoshop or the blossom has been dyed.

3. Valley flower.

Some people believe that the dahlia was a homophone for the Swedish word "dal" which means valley, so it is sometimes called the valley flower. However, the truth of the naming is more likely to be that it is named for Anders Dahl, a student of Linnaeus. Linnaeus, by the way, didn't live to see the dahlia. He died in 1778, eleven years before the plant was introduced to Europe in 1789. Come to think of it, Dahl never saw his namesake plant either. He died two years before it appeared.

4. Mexico's national flower.

Dahlias are native to Mexico. They also grow in Central America and Colombia. The dahlia was named the national flower of Mexico in 1963.

5. Getting seedy.

Dahlias can be grown from seeds which you can collect as with any other flower. However, it won't come true to its parent and bees will cross-pollinate it with other dahlias in the vicinity. Dahlias can also be grown from their tubers, which must be dug up each fall after the first frost has passed. Let the tubers dry out a couple of days, wash off the soil, dust with fungicide and store in slightly damp peat moss in a cool place (4 to 10 degrees Celsius); the ideal temperature for your refrigerator is about 4 C. Seeds germinate in six weeks.

6. Showstopper blooms.

For the biggest blooms, pinch out the terminal bud above the second pair of leaves when your plant is three to four inches tall. This will produce two stems. When the flower buds form, there will be three buds. Pinch back the two smaller buds on either side of the centre one. Look down each stem and pinch out the small buds that will hide in a leaf axil.

7. Water pipe.

While dahlias were once thought to stupefy bees through some nectar-based narcotic, this is now known to be untrue -- bees just get dizzy with the delectable sugars. But it is true that the Aztecs used the stems of some dahlias as water pipes -- literally. They carried water in the hollow stems on Dahlia imperalis, which is known as the dahlia tree and can grow 20 to 30 feet in height. The hollow stems can be three inches in diameter. Hunters would also look for these plants when away on long hunting treks. The flowers emerge from the top of the plant as with any perennial.

8. Symbols.

Aztecs saw dahlias as the symbol of the sun. They are said to stand for dignity and elegance. They can also be seen as a sign of warning, of change, of travel and as a portent of betrayal. If you want to let someone know that you intend to betray them, send them a dahlia. They are the flower for the 14th year of marriage...

9. Medicinal.

The Aztecs fed dahlias to epileptics. There are no reports as to the efficacy of this treatment. Dahlia petals were used as poultices, and to treat insect stings and to clear complexions. Inulin extracted from the dahlia tubers (and also from chicory and dandelions) was used to treat diabetes before insulin was discovered.

10. A never-ending source of wonder.

There are 20,000 cultivars of dahlias and these are divided into 18 groups. This stems from the fact that dahlias are octoploids, meaning they have eight sets of chromosomes where most plants have only two. This is one of the characteristics that make them easy to hybridize. Flowers range in size from two inches in diameter to 14. Very few of the cultivars are scented.

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