Dahlias are beautiful and can be good for you


The beauty and medicinal purposes of the Dahlia goes back in history to the 1600s but it was named after Anders Dahl (1751-1789), a Swedish botanist. In 1963 it was declared the national flower of Mexico.  For your garden, it can produce a profusion of color from a variety of sizes and shapes.

Dahlias and their cultivation
Dahlias are an interesting flower to grow and they come in all sizes from twelve to eighteen inches tall to big ones as high as seven feet with flower sizes from about two to three inches across to over ten inches across, so you can see there is quite a variety.

They require a sunny location with well drained soil. If the soil is heavy, work in some peat moss and or mushroom compost to lighten it. If the plants do not get plenty of sun, the stems will get lanky and the blooms small. At planting time, work some bone meal into the hole. They can be grown in containers but the container should be at least twelve inches in diameter for each plant. It is recommended that any dahlia over three feet tall should be well staked with bamboo stakes, metal stakes or tomato cages.

Dahlias can be grown from seed, cuttings or tuber division.

Seeds should be started in March or early April. Using seed starting soil in trays, lightly covering the seeds.

They require light to germinate and a temperature of about sixty-eight to seventy-five degrees. Do not put them in the dark as light is required for germination.

When the seedlings are large enough to handle, usually when two proper leaves are seen, transplant them to four inch pots into a good potting soil. They will flower the same year.


Cutting can be taken from tubers stored from the previous year (more about storing tubers later). The tuber should be taken from its storage in March and put into moistened peat moss under lights.

It should start to throw shoots. When the shoots are about three inches, cut them off at the base and plant into four inch pots using rooting compound on the base of the shoot.



The pots should be kept under lights in a humid environment until they are rooted. Do not over water otherwise they may rot. The cuttings will produce plants that will bloom and produce tubers the same year.


Tubers which you have overwintered should be planted in a hole the same diameter as the tuber. Dig the hole and add a little bone meal and plant the tuber, trimming the old stems level with the ground. If you plan to stake them it is a good idea to insert the stake before you fill in the hole to avoid putting the stake through a tuber. Large tubers can be divided, but make sure there is at least one growing shoot on each division.

Overwintering tubers
If the tubers are left in the ground over winter they will not survive and will rot.

When the plants have been blackened by frost and before the ground freezes it is time to lift and store them. Cut the stems back to about ground level or an inch or two above and carefully dig up the tubers with a spade or fork avoiding damaging them. Shake off as much soil as possible. I stand them upside down for a day or so in the basement. The reason for this is that the stems are hollow and contain a lot of water. I personally have found this can rot the tuber. I then put them in boxes of peat moss and store them in a cool dry place. I use my back inside stairwell which is unheated but frost free.

Planting out times
Any time from the end of April to mid May. In the Chicago area, I prefer the latter.

Water the plants lightly until they get established and the shoots are above ground. After that, they require heavy watering at least once a week. In hot weather, they require even more frequent watering..

Fertilizing Dahlias require a low nitrogen fertilizer such as 5-10-10 or 1-20-20. The nitrogen is the first number of the three on the fertilizer packet. Do not over feed them.  Feed them about once every three to four weeks. Too much feeding, particularly with a high nitrogen fertilizer, will cause the plant to get very weak and spindly and the tubers will shrivel and won't overwinter.

Dahlias make very good cut flowers my favorite is Edinburgh pictured here.

For more information: Growing; medicinal; general



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