"Double" refers to the type of flower. "Tuberous" refers to the type of plant: Born of a tuber. There are two types of begonias: tuberous and fibrous. Fibrous are grown from seeds, do not form tubers and are annuals in colder regions. They are only propagated from seeds. Tuberous are also grown from seeds but form a tuber, which can be carried over from year to year, and these can be propagated.

As to "double", it is the type of flower. Doubles have multiple layers of flower petals and resemble a full rose. The other type is "single", which is a simple, single flower. These are not as exotic as a double but if you find that less is more, you may prefer the singles.

Get some catalogs and enjoy the pics.

Thank you very much! You have been helpful!

Billy Rae

Oh, I miss Elizabeth! She would remind you that ALL BEGONIAS have fibrous roots. Tuberous begonias have to have roots coming from their tubers or they would just be lumps of plant matter that would turn into compost. All begonias can be grown from seed. I think when you speak of 'fibrous begonias', and I first learned that as a name for them and it is quite common in the trade so I hope I don't come across as too nasty for words, are what I also learned originally to call 'bloomin' fools'. The proper name is B. semperflorens, which is basically a fancy way to say the same thing--it means 'always blooming'. The only begonias you can't grow from seed are the hybrids which would not come true from seed but might give you something you like better. The semperflorens grow just fine from cuttings--I've done it many times. Don't think the tuberous are as easy from cuttings but since I can't grow them here I don't know. But you leave out all the wonderful cane-types, and the shrubs, and the rhizomatous, and the Rexes, and the trailing/scandant, and the thick-stemmed. Check the American Begonia Society site, and the Astro Branch site which you can access from it, for pictures of many, many begonias you may never have dreamed of. One of my favorite kinds are the ones which, when I show visitors, they say 'That's a Begonia!?'

Hi
What are the best growing conditions for tuberous begonias please?

I have a big basket all in bloom & wonder how much water , sun etc to give them
Christin in Melbourne

I hope somebody who knows what they're talking about answers you! Way back when I lived on the west coast I really didn't work very hard to grow tuberous begonias and they grew very well in spite of me. I would say they like bright shade, cool to fairly warm temperatures, moist soil, and lots of organic matter including perhaps some barnyard fertilizer. We had cows so I probably used that. Good mulch will help keep the soil moisture even. They don't like heat and humidity like I've got! And I remember I started the dormant tubers early on top of the refrigerator for a little extra warmth, but I don't remember how early.

Howdy y'all ! I just bought some double tuberous begonias , the hanging basket type - I think. I plan to plant them in a week or two.
I used to grow them in Washington State and am wondering how they'll do here in Central Texas. I also have Dragon Wing begonias which I propagate from cuttings in water and then pop in good soil after the roots sprout . Some of them are still in water filled cobalt blue glass containers and are blooming like crazy.
Anyone know how the tuberous kind will tolerate the Texas summers ??

From what I've learned here in southern Louisiana, good luck. We aren't as hot as central Texas I think, and more humid, but I don't think they like either. The first tuberous begonia I saw here was at the local university botanical greenhouse and it really looked awful. When I went to an ABS convention in San Antonio there was a guy, whose name escapes me, who was trying to hybridize tuberous begonias that would survive there. I don't know how he's doing--know he had to move and give up most his greenhouse, and it seems like we would have heard if he had gotten somewhere. Maybe I'm lazy, and I certainly admire folks who try to stretch the boundaries, but I tend to grow things that will like the conditions I've got and not grow things I have to torture into surviving. There are so many begonias that will grow well in our conditions, no matter where we are. (Well, maybe not Antarctica!)