Dahlias are considered one of the most spectacular garden flowers. There is a great variety of form in dahlias, from the showy dinner-plate size to the bright, little single ones.
Dahlias are natives of the mountainous regions of Mexico and, although they grow in a warm country, they are actually temperate plants requiring cooler conditions. There are 30 species and 20,000 cultivars of Dahlias.
Facts About Dahlias
- The dahlia is named after Swedish 18th-century botanist Anders Dahl.
- The dahlia is the official flower of the city of Seattle.
- The dahlia originated in Central American in the 16th century.
- Spanish Botanists discovered it growing wild on the sandy hillsides ofMexico.
- The first tubers arrived in Europe at the end of the 18th century, sent over to Madrid by the Spanish settlers in Mexico.
- Andreas Dahl (after whom the plant is named) regarded it as a vegetable rather than a garden flower, but interest switched from the edible tubers to the blooms when the first varieties with large, double flowers were bred in Belgium in 1815.
- The favourites in those days were the Ball and Small Decorative Dahlias. Now it is the Large Decorative and Cactus varieties which capture the public fancy.
- Dahlia Plants ranging from dwarf bedders (twelve inches high) to giants taller than a man. Flowers range in size from an inch to the largest dinner plate.
- The first dahlias were brought to Europe by the early explorers and over the centuries, through hybridization, developed the modern dahlia.
- The Dahlia seeds will germinate a little faster when we use a heating mat, or place them on top of a refrigerator for heat.
- Dahlia bulbs are a subterranean root system, comprising many distinct tubers, each a separate lump. These allow the dahlia plant to mature year after year without benefit of seed or spores. To sprout the next season, each tuber must have one eye.
- Dahlia pinnata, is referred to garden dahlias, but this really is not accurate since all modern dahlias are hybrids between species. The most common hybrids are the products of crossing Dahlia coccinea with Dahlia pinnata.
The first named species of dahlia imported into Europe were Dahlia pinnata, Dahlia rosea and Dahlia coccinea.
Varieties of Dahlias
There are wide varieties of dahlias based on their sizes, flowering patterns and resemblance to other flowers-
Single Orchid Dahlias (Star)
Double Orchid Dahlias
Dahlias need full sun and appreciate steady moisture and regular feedings until the flowers start to appear. At this time, taller varieties may need to be staked. For a bushier plant, pinch out the growing shoot after plants have produced 4 to 6 pairs of good, strong leaves. A number of buds will appear at the top of the stems. To get maximum sized flowers, some buds should be pinched out. If only one bud is allowed to develop, the largest possible flowers will be produced.
- Prepare the soil by digging to a depth of about a foot and amending with compost if necessary before planting.
- Plant seeds about 1/2 inch deep in a pot, pack, or flat.
- Cover the seeds with more of the soil medium or pure vermiculite and add water until the soil is thoroughly moistened.
- Placing a film of polyethylene or a pane of glass over the container will keep the surface moist and enable the seeds to germinate undisturbed.
- Place the container in a warm location (not in direct sunlight) and allow seeds to germinate.
- Dahlias normally germinate in 5-7 days at temperatures between 70-80 degrees F. When the new shoots are first visible, remove the plastic or glass.
Dahlias Plant Care
- Dahlia plants become massive and need support.
- The large flowering types, particularly, become very tall and, because of the succulent nature of their stems, require support to prevent plant breakage and loss of large blooms.
- Tie plants to the stake that was driven next to them at planting time.
- When using a string or soft twine for tying dahlias, tie loosely to the stem to avoid constricting the developing plant.
- Start tying dahlias when they are about 1 foot tall, and continue to tie them at intervals of approximately 1 foot throughout the growing season. Individual stalks should be tied when buds begin to form and enlarge.