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I bought three dahlias of the "Happy Days" series from B&Q in June as space fillers and they have been fantastic, growing to over 2' with masses of blooms. They still have lots of buds, but I need to dig them up to plant bulbs. The first plant has been removed and transferred to a pot, but it didn't have tubers, only roots.  Is this a new annual form?


This one didn't get answered while the forum was sick but I know nothing about dahlias

This is an interesting question.  I think they all do form tubers after a season's growth but, although I grow several dahlias, I do not know for sure.  Every dahlia for me has formed tubers.

Dahlias are tender perennials ..  Or, ..are some simply annuals?  

Well Verdun, hopefully someone will be along shortly to answer that question!  

I have been told by a supplier some done by cuttings in the spring may not develop tubers and have been bred to concentrate growth more into flowering. Not sure if this is correct though? I wonder whether the use of growth retardant could affect tubeer production? The ones we had to try have produced tubers though


If I was to guess, I would say they form roots and then, when ready, form tubers.  The natural habit of with some tender to, eventually, form tubers.


What about Begonias? 

Do these form Corms too from those bedding plants that you buy? ( I bought the Illumination variety)

If no-one knows I guess I'll find out come November :P


Illumination begonias are tuberous, they will die down to a large corm, which can be saved in a frostfree place and then regrown next year.

There are fibrous rooted(semperflorens) begonias used in bedding displays (small flowers), which will not form a tuber or corm.


Thanks fidgetbones

This will save me some money for next year

I don't like those bedding begonias anyway!


Dahlias grown from seed or cuttings do eventually grow tubers.

Think we are agreed......dahlias do all form tubers eventually


Have you kept them well watered?

Morning sara

Yes,,you can dig them up, split them, move them, etc.

Just make sure each clump of tubers has a piece of STEM.  won't grow otherwise.

Strictly you wait until frosts blacken the foliage then you bring indoors to,overwinter. However you can do it now.  I would put half approx back into the area you want it....and pot up the rest.  I would divide these clumps again to,overwinter if you have enough

Yes Blairs, I have. 

I'm wondering if anyone else has bought any of these Happy Days dahlias.  They come in various very bright colours with dark purple foliage. I googled them and found they were sometimes described as annuals and sometimes as tuberous perennials.  As I have dug them up with a ball of soil to put them in a pot whilest still in flower, I'm wondering if there are some tubers hiding in that soil.  Are there usually roots at the bottom ends of tubers?


Tubers are basically swollen roots which act as a food store, so the unswollen ends of the roots look just like normal plant roots.  I grow all my dahlias from seed each year and they all produce tubers, but late-sown ones may not have time to produce large enough tubers to survive the Winter by the time the frosts come.  Regular dead-heading will encourage tuber formation as if seeds are allowed to form the plant may decide to put all of its energy into those instead - plants do whatever is most efficient in order to reproduce or survive.



I asked about water as tubers are 95% water, hence they are not frost hardy. I have grown similar small Dahlia (Bishop of Llandaff) from seed and they had small thich roots rather than tubers in their first year - they were difficult to overwinter and restart. I did notice that the seedlings with most water had the thickest roots/tubers.


I leave my dahlias in the ground in winter and most survive. Arabian nights, Park Princess, Bishop's Children (that I grew from seed) and some others even survived the year it was -17°! Pooh and the others I planted last year (forgotten names) all survived -10°. I live in Dordogne, winters are usually colder than in UK, last winter and spring were very wet, but years of manure and limestone rock under the earth mean my beds are well drained, although it was clay to start with.

I received a pot of dahlias for Mothers Day.  Lovely,  but the stems started rotting...leaves turned yellow and dried.  I decided to move them into my garden in August to try and save them.  Any suggestions  or advice about what went wrong.  They did not have any tubers formed!!


It sounds as if they'd been forced into flower very early ... How are they doing now?

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