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Features
Pale orange flowers, darkening towards the centre, on tall stems. Mid green leaves.
What to use it for
Would be ideal in any style of garden, in borders or containers. Useful for cut flowers.
How to look after it
The tubers are unlikely to withstand the winter wet and cold, so it is recommended that you lift them in autumn after they have flowered, clean them and store them somewhere dry and frost-free. Replant them in spring when the worse of the frosts have passed. If you live in a warmer climate and have well draining soil you could have a go at leaving them in the soil as they may survive. If you are risking this, then mulch them well in the autumn.
In the spring mulch them with some rich organic matter (eg well rotted compost or farmyard manure) and feed them with a general purpose fertiliser when growth begins.
Ensure that you stake the plants as dahlias can easily flop over. If you want bushier plants with more flowers, pinch out the growing tips.
Make sure you keep them well watered in any dry periods for a good display.
How to prune it
Deadhead regularly to prolong the flowering period.
In autumn when the flowering is over cut the whole plant back to just above ground level before lifting the tubers.
How to propagate it
Clumps of dahlia tubers can be divided in the spring before they are re-planted. Use a clean, sharp knife and slice the tubers into sections, making sure that each section has a healthy dormant bud (known as an ‘eye’) on it. Dust all the cut surfaces with a fungicide to help prevent infection. Plant the sections immediately.
To get even more new plants, you can take basal stem cuttings from dahlias in late winter. To do this you need to get the dahlia tubers growing earlier in the season, so plant them in potting compost, leaving the tops of the tubers exposed, and keep them moist in light shade at at least 12˚C. They should then start growing. When the new shoots are around 10cm tall, use a clean, sharp knife and cut each stem out, taking a small chip of the tuber with it. Remove any leaves from the lower part of the stem and then pot it up in free draining compost (eg cutting compost) and keep it humid and at about 19˚C. Gradually reduce the humidity as the cuttings start to grow, pot them on, and harden them off before planting out after all chances of frost have passed.
You can also take softwood cuttings from dahlias in the spring. Encourage early growth by potting the tuber over winter (keeping it moist but frost free) and then moving it into a warmer spot (minimum 10˚C) in early spring to stimulate early growth. Then take softwood cuttings as normal.
Common problems
There are a lot of pests which enjoy munching on various parts of dahlias, including aphids, leaf miners, two spotted spider mites, slugs, earwigs and occasionally capsid bugs and caterpillars.
In dry conditions, powdery mildews can cause problems and botrytis may be an issue in wet weather. Fungal infections can also affect stored tubers.
Finally viruses may also be a problem with dahlias, causing stunting, leaf markings and distortion.
Other useful information
Has received the Royal Horticultural Society ‘Award of Garden Merit’.
The dahlia is named after the 18th century Swedish botanist Anders Dahl, a student of Carl Linnaeus. Around the same time, in Germany, it was also named ‘Georgia’ after the Russian botanist Johann Gottlieb Georgi, and some still know it by this name.
