For gardeners who want to offer a good variety of color and texture in their garden but also want to keep things simple, there is the dahlia.
With more than 57,000 registered cultivars, this plant group offers a huge selection. Dahlias are in the Asteraceae family which includes chrysanthemums, sunflowers, daisies and zinnias. The traits of these relatives are evident to some extent in the different varieties we can plant today.
The dahlia is native to Central America and northern South America. It was cultivated for centuries by the Aztecs. The roots were a source of food, the stems were used as water pipes and other parts of the plant were used to treat epilepsy by the Aztecs. Most of the food and medicinal uses of dahlia stopped after the Spanish conquest. It was first noted by Spanish explorers in 1525, but was not described botanically until 1570.
The Spanish brought “plant parts” and later seeds back to Spain where Franciscans tried to successfully grow the plants. Plants were sent, or traded, with other botanists in Germany, France, Italy and finally, England. Growers in the colder countries soon learned the dahlia plants could best survive if they were kept in greenhouses.
The growers were impressed by the variety of flower types and colors they could produce. They also experimented with plant size, leaf shape and color. There were 18 original species described, but through cultivation and hybridization that list is much longer now. The result of all of this is the broad variety of specimens we have available today.
The flowers can be a couple of inches wide or they can be huge, as in the “Dinner Plate” varieties. The petals can be single and simple, like an anemone or daisy, or they can be massed like in a chrysanthemum. The plants themselves can be only 12- to 18-inches tall and of the same width, or they can grow up to 4-feet tall and wide. There are dahlias that will fit in almost any garden.
Dahlias are easy to grow and are an excellent choice for a beginning gardener. Experienced gardeners also enjoy the ease with which they can add these bright colors to their landscapes. Another plus is these flowers are mostly pest free. They are pretty cheap as flowers go so that is another nice feature.
Dahlias are usually bought as a small mass of roots. A short piece of the stem was left on the roots so the gardener will know which end is up when they are planted. Work the soil to about 6 or 8 inches deep and at least a foot wide for each section of roots. Plant them so that they are covered with about 2 to 3 inches of soil. Water well to settle them into their new home. These plants are also available in flower pots.
As a general guideline, the best time to plant is the end of April through the middle of May. Do not plant until after all danger of frost has passed and the soils have started to warm up. Dahlias are not cold tolerant so we usually treat them as large, beautiful annual plants. I have seen the occasional dahlia survive a mild winter, but that is rare.
These plants prefer to grow in full sunlight. They want the bright sun to shine down so they can show off their colorful flowers better. They can tolerate some shade in the morning, but do try to find a sunny afternoon spot in the garden.
They will grow best in a rich, organic soil that is slightly acidic — pH from 6.5 to 6.8 — like most of our summer annual plants. You can add some compost or manure to the soil to help boost growth but I have seen them grow well in clay soils. You can add lime to the soil if it is too acidic.
The dahlias respond well to fertilizer. For each dahlia, add two tablespoons of 5-10-5 or some other food for flowering plants. You can side dress with another two tablespoons when the flower buds form or you can apply a water-soluble plant food to the foliage every two weeks. Dahlias can tolerate dry soils for short periods, but it is better to keep the soil moist, but not wet, throughout the growing season. Water dahlias about as often as you would any annual flower beds.
Once they start to flower, you can remove fading flowers to encourage additional blooming, right up to frost. The flowers are colorful and attractive. You can get almost any color you want. They can be cut and brought indoors to use in fresh flower arrangements.
If you have a sunny spot where you want to have some good color. And you want a low maintenance plant that is easy to care for. Consider using a group of dahlias.
Spring is coming. Enjoy your garden.
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