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lochcarren

Growing begonia tubers

lochcarren
19 years ago

Every year I try to grow the gorgeous double begonia tubers that they sell in those little cardboard bins at the garden center. The pictures looks so pretty. So I plant them in bowls and pots with good potting soil But I always have the same two problems

#1. There are always a few of them that simply don't sprout. Just sit there in the ground. Still firm and fresh to the touch, but no leaves.

#2. Should some manage to grow and get tall, they seem to get sort of rotten where the stem meets the tuber, and either break off or die. Usually when they're looking the prettiest, of course. Very frustrating.

I'll appreciate any advice anyone can give.

Lochcarren

Comments (18)

  • osen1952
    19 years ago

    Did you ever get them blooming?

  • bmchan
    19 years ago

    First: Try getting them started indoors in pots. Putting them in the ground is high risk. Use a sterile, seed starting mix. I usually start them in late March indoors (Zone 5 MA).

    Once they have a couple inches of growth, transplant them into the garden from the pots. I no longer put them in the ground, but prefer to grow them in clay pots. I carry them over from year to year and those that go in the ground invariably get chewed up by some kind of soil creature.

    Finally, the better bulbs come from mail order or online sources. But the store bought ones can be fine.

    Oh - on the stem breaking issue. The bulbs should be buried an inch or so below the soil surface (check your local growing requirements). I also take small tree twigs and use these to support taller stems. Always be careful not to nick the tuber. Local soil or humidity may impact your experience.

  • lochcarren
    Original Author
    19 years ago

    Yes, I've had them blooming. That's about the time the stems break. Sometimes I've blamed the squirrels (not unjustly, I suspect) for jumping down on them and breaking them, especially when they're in baskets hanging under the trees.

    But generally I've found a sort of brown mushy rot at the base of the stem, that I think must be some kind of fungus disease. This year, as I spray fungicide on my roses, I'm going to squirt a little fungicide on the tuberous begonias where the stem enters the soil, and see if that makes a difference.

    I always grow them in pots, too.

  • rhodie_chick
    19 years ago

    I had the same experience this year as locharren with the rotting st the stem/tuber interface just when the blooms were looking real good; These plants were in pots filled with steile potting soil.It seems that the problems started when i watered every day and left them outside during rainstorms in a protected corner of the house. i plan on getting better tubers next year; howver, how can I avoid the rot situation? would planting in an area that gets better air circulation help?

  • Begoniac
    19 years ago

    If you have hot summers with warm nights you'll never have much luck with tuberous begonias. They are hybrids of high altitude tuberous species, so unless they get relatively cool nights you can't grow them successfully. It would be interesting to compile a list of areas of the country where they can be grown. I know that Southern California, the Santa Barbara area, is excellent for tuberous. Mountainous areas, of course. I remember seeing a porch full of them in the mountains of North Carolina. The Pacific Northwest is good, although I understand there are microclimates there, so maybe not all areas are suitable. Scotland is famous for its tuberous begonia growers, like Hugh McLaughlan.

    Elizabeth

  • lochcarren
    Original Author
    19 years ago

    Thanks, Begoniac, for that info. I've often wondered why I have so many problems with tuberous begonias here in Ohio. They get tall and scrawny and tend to break. Interestingly, we found some smaller-flowered varieties with dramatic, dark leaves that are doing quite well; don't seem to have the same set of problems, or at least to the same degree, as the large-flowered tuberous begonias.

  • oyster2
    19 years ago

    Nova Scotia is begonia heaven, especially along the coast. They are extremely common here, such that few people take the trouble to save and nurse the tubers through the winter. They are cheap enough to buy from the nurseries in the spring. If the supermarkets don't carry them, it's probably because begonias are so fragile and inclined to snap off.

  • bmchan
    19 years ago

    I have a plant that is approaching 3 feet tall in Central MA. I have staked my plants this year with quarter inch bamboo stakes. It has helped to prevent breaking of the stalks, although it is inevitable.

  • Begoniac
    19 years ago

    Holy Moly! Do you have a picture of it you could post? It's not easy to grow them that tall. So now we can add Nova Scotia and Central MA to the list.

    Elizabeth

  • jillca
    19 years ago

    My Mom, for over 40 years grew begonias in Ohio (Cleveland), in the ground, on the north side of the garage. They were always beautiful. For some reason, hers always stayed nice and stocky and I remember that she seldom had to stake hers.

    Mine, on the other hand, are healthy, but I always have to stake them and I seldom get the beautiful male flowers, just the small female ones. sigh!

    jill

  • Freda
    19 years ago

    You can also add Newfoundland to that list. I have grown them for many years and at one time had over 40 tubers.

  • akgriff
    19 years ago

    They grow great here in Alaska also. I think the cool short summer nights help. We get huge hanging baskets.

  • claubill
    19 years ago

    I'm a beginner at this. I bought some corms and we had such beautiful flowers this summer. Now I'm ready to start propagating from the leaves. Do I leave in light or can I put them in the basement?

  • Loretta NJ Z6
    19 years ago

    I also have grown them in the past but now the local greenhouse offers them grown out at the same price as the tubers so it doesn't make sense for me to start them unless I go for the fancy mailorder types. Plus theirs come out shorter and stockier than mine. Anyway, they do better for me in pots as well and I have the same root rot and tipping over problem in NJ. I've gotten some fantastic flowers though but some didn't live up to the picture. I will always remember seeing the very first bloom. It was a huge bright orange foward facing bloom as beautiful as a rose visible from any line of site. I don't think I ever got a bloom as impressive as that first one though I've tried a couple of years after. Maybe its just the memory...

  • lochcarren
    Original Author
    19 years ago

    Thanks for all the responses to my original question. I'm convinced that excessive heat is a major factor. And here in Ohio, it is pretty hard to escape that.

    It also convinces me to be careful not to assume that just because they offer it in the local nursery, it will grow here. They'll sell you any number of things unsuited for local conditions, without any warning. We see scores of begonias offered here, and I dont know anyone who claims they do well.

  • shebob
    19 years ago

    Tuberous begonias also grow well here in coastal British Columbia. I have one tuber (6 years old) that produces enoumous canes over 3 feet tall, with spectacular orange flowers. This fall the tuber was so large that I decided to measure it. It is 9 1/2 inches long, 7 inches wide (at the widest point) and nearly 4 inches thick (deep). Must weigh over one pound. I will have to increase the pot size again this spring in order to hold the bulb. It was given to me as a little seedling 6 years ago and I don't know the exact variety. Can anyone tell me if it is common for the tubers to become so large? Or do I have a freak on my hands?

    Thanks

    SheBob

  • bmchan
    19 years ago

    That tuber is probably a good candidate for dividing. I have not done this yet, but I believe the process is to cut them in the spring. The divisions should include sprouts. The cuts are treated with a fungicide powder and allowed to cure. Again, I have not done this, so get certain advice. I am planning on doing this in the spring.

  • bearberry
    14 years ago

    Should tuberous begonias be fertilized? If so, with what?

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