Frequently asked Question about Tuberous Begonias

What is a Tuberous Begonia and how is it different from other types of begonias?
The clue is in the name. Tubers are basically storage roots that allow the plant to rest for a period and then come back to life. You eat potatoes and yams, these are tubers too.

How do I know when my begonia should go to sleep?
In the tuberous begonias the tuber grows and stores energy in the fall when the temperatures get colder and the hours of day light decrease. Here in the Southern California we can stay so mild in climate that if you have outdoor lighting that stays on at night this can fool your tuberous B into thinking it is only September not November. This does not apply to you...Chicago, Boston or Bismarck. The begonia can be fooled but it is not stupid. If you live where it freezes in the fall your begonia will make its tuber at the right time and it is up to you to take it in when before the first real frost. I live in San Diego la la land and the idea of frost in the fall seems most strange.

Now that you know what makes your begonia go to sleep you won't be upset when it looks like it is dying. This should happen in late November. Just slowly take away the water and when the begonias are down to nothing then you know that they are not dead. Just

We do that at Weidners so that you can buy your blooming Non Stop in late March and not have to wait until May. Because the Non Stop variety requires fewer hours of light than the giant type they are easier to fool. When you see greenhouses with lights on at night they are manipulating 'day length' to fool some of their crops. It is a little complicated but if you think about it you'll get it. By the same token Non Stop begonias stay in bloom later in the

Can I divide my tuber when it gets big?
Yes and no. This is one of those all or nothing gambles. I did it this spring for a customer who had a very very large old Tenella variety hanging basket. We have difficulty in getting Tenella's so she both wanted to divide it and to give us another start.
This is what I did and it seemed to work. Since there is a chance that cutting into the tuber will make it rot you are doing this on your own risk.
I wanted to see which parts of this big tuber were good so I waited for it to begin its growth. Didn't want to break dormancy outside in the chilly weather so into the greenhouse went basket at all. Only enough watering to make it wake up. The extra warmth did the trick. I could now see what was old and not about to grow and cut that out and throw it away. Then I took a sharp knife and made my cuts where you could see that new tubers had formed. They were still all hooked up together so I separated them. Let them dry off for a day and then planted them up in new pots. Watered in gently and put them back in the warm greenhouses. That worked. If you cut your tuber up before it sprouts be very sure to let the cut ends dry. Good luck!

What about Mildew
Mildew appears when the temperatures are nicely warm in the 70's and there is little air circulation. It is important to spray right away. Mildew doesn't go away easily by itself and the damage it does is permanent. Any good fungicide is OK. Neem oil will often work as it coats the mildew. It can burn so don't use it when it is hot. The baking soda and water recipe raises the PH higher than the mildew likes. It has no residual effect and can also burn if you make it too strong. Recipe as soon as I have another moment.
Whole milk works but leaves a residue.

June 08...We have a new organic different type of fungal inoculant but I haven't had any mildew to try it on yet. More on that later.

This page is still being worked on. More questions and answers coming. Let us know your questions and we can be more helpful, Evelyn Weidner

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