Dahlia growing South Africa Q&A

When to plant dahlia tubers or bulbs in South Africa?

The best time to plant dahlia tubers or bulbs in South Africa is late Spring. October and November are the best times. Dahlias like warm soil to start sprouting and in South Africa the last frost date is end of September depending on the area you live. In Cape Town and other coastal areas it is safe to plant in September. But in the Eastern and Northern Cape it is safer to plant in October. Gauteng should also wait for October to start planting.

Where to buy dahlia tubers or bulbs online?

There are a few online options for buying dahlia tubers online in South Africa. Most of the online shops sell pot tubers imported from Europe, especially the Netherlands. These tubers are imported from the northern hemisphere and need to be planted as soon as possible for them to grow successfully. Love Dahlias has the largest selection of locally grown dahlia tubers in South Africa. All the tubers we grow have been growing in South African soil for at least one season. We supply large viable dahlia tubers to the public.

What is the difference between dahlia bulbs and tubers?

Dahlia tubers are sometimes called a bulb, but they are technically a tuber, similar to a potato. Just like potatoes, the tuber sends up a shoot that becomes the plant, which produces leaves and flowers. The original tuber will rot away and under the ground the new tubers multiply each year (again, like a potato).

When should I buy dahlia tubers?

The best time to buy dahlia tubers is in spring. Dahlia tubers in South Africa overwinter in the soil and get dug up late in winter. So the best time to get your hands on fresh dahlia tubers is in early September. We open our dahlia sales in Autumn, and our customers have the chance to pre-book tubers for the new season, but all tubers will be sent in mid September.

How many dahlia tubers can you get from one dahlia tuber?

A single dahlia will produce between 4 to 12 dahlia tubers in one growing season. This also depends on the tuber production of the variety. Some dahlia varieties are not very good tuber producers and will only yield a small amount of tubers every season. How long the growing season is can also attribute to the amount of tubers the dahlia plant produces. If fertilized correctly a dahlia that has been growing for a few months will produce more dahlia tubers than one that only grows for a short while.

Do dahlias come back year after year?

Dahlias start growing when the soil heats up and the days get longer. When winter comes your dahlias will die after the first hard frost. The tubers that grow beneath the ground are unharmed and can live to perform again year after year given a little care from you. Some lift dahlia tubers and store them over winter, then replant the following spring. Here in South Africa we can leave them in the ground.

Do dahlias like sun or shade?

Dahlias prefer full sun to partial sun. This means they need at least 6 to 8 hours of full sun per day in order to do well. But if the sun is too hot and temperatures routinely exceed 35 C the plants may stop flowering. If excess heat is a concern, choose a spot with morning sunlight, and some afternoon shade.

Are dahlia tubers expensive? Why do they cost so much?

Dahlias are labor intensive. Tubers must be dug up each year by hand. Dahlia tubers are quite fragile and break very easily. If they break, they are worthless therefore hand digging is the most gentle method. Once the tuber clumps have been dug up, they must be divided into individual tubers by hand. All these factors into the price of dahlias.

The consumer demand for dahlias is strong and there is only a limited amount of dahlias available. Certain varieties are better tuber producers than the others that also influence the price of dahlias. Boom Boom, Nepos, Otto’s Thrill, Lavender Perfection and the Cornel dahlias have been grown in South Africa for several years. There is a lot of their tubers available, hence the cheaper price, Newly imported varieties are not available in large quantities and are therefore more expensive.

Are bigger dahlia tubers better?

Size does not matter. The one common concern people have when they receive a dahlia tuber is that the tuber is too small and will this produce a quality dahlia plant? When it comes to tubers, size doesn't matter. You just need all three parts (body, neck and crown) of the tuber to be present and the tuber will send up a new shoot and start to produce a plant and then new tubers.

How long does it take dahlias to bloom?

Dahlias can take anywhere from 12 to 16 weeks to bloom after planting. Once they start blooming, they will continue to bloom until the first frost. Most dahlias take 100 days to fully bloom. This means that 3 months after the day you planted the tuber in the ground the plant will start to flower.

What is the rarest color of dahlias?

Black dahlias are extremely rare: less than 20 of 200 000 species of dahlias are black. But new research from scientists has revealed how these dark flowers get their color. Analyzing the pigment makeup of dahlias, scientists in Austria found that black dahlias contain far more anthocyanins, and far fewer flavones, than other colors of dahlias. As technical as this all sounds, it could have exciting implications for the future. This knowledge could be used to improve techniques for flower breeding, helping dahlia lovers to grow the perfect black dahlia.