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What are best conditions for Rex Begonias?

I jusr bought 3 different Rex begonias as an impulse purchase. I had some a few years back, off and on, and always ended up losing them in the winter to some kind of mildew disease: spots would appear and rot would spread from that point.

I want to put these in my upstairs bathroom: a window which has diffused light (stained glass window). There is a skylight above. Most potted plants do well there.

What can I do this time to forestall problems? This is not the same location where I had the other ones that died. Are they a "keep moist" kind of plant, or one I should let dry out between waterings?

Comments (6)

  • 17 years ago

    Well, let me start off by saying, i am no expert with rexs, much less housplants.

    But my first plant is a Begonia Rex.
    The last pic is from a week ago

    the conditions i have had it in, is similar to the one you have posted.
    A Bathroom w/ a frosted west facing window
    i believe the key is that I close the bathroom door when taking showers, (quite a small bathroom 4 x 5 ft)
    and it supplies the rex with enough moisture in the air, as i was getting brown leaf edges / small spots, when i had it in my living room.

    as for the watering question, I tend to let the soil dry out almost completely before i water again, and completely soak the soil. i can honestly see the plant in need of water, with the leaves drooping a bit. upon watering, the plant bounces back within 15 minutes, and the leaves are back up.
    I have always been hesitant to keep the soil moist at all times. hearing horror stories of Root rot.

    as for wintering the plants, i have no experience.
    although i have read some info, suggesting to stop fertilizing, water with hesitation, keep in a bright spot, tend to the yellowing / dead leaves to prevent mold / rot

    Hope any of my info can help you. and i know there are a few rex experts floating around on this board.

    Good luck

  • 17 years ago

    Andrew, the begonia looks beautiful. You must be making it happy as it seems to have grown and picked up color.
    Thanks for poating the pics.

  • 17 years ago

    I am seeking the same advice. The only way I can keep my rex alive is in an aquarium. I am beginning to feel what is the point to having one. But I have a potted plant and a cutting that looks OK. I need to pot the cutting. I remember someone who used to post here say she uses bark as a potting medium. Does anyone use bark?

  • 17 years ago

    I've heard the recommendation to use bark, but the only bark I've been able to find is too coarse. I respect the opinions of the people who have recommended it and shall continue to look. Actually, I have some of mine in a commercial potting mix that has a lot of bark in it and they do well if I don't over-do the 'let 'em dry out between watering' part, which I do sometimes. Then I lose leaves, but not the plants. They do seem to enjoy high humidity--I grow them outdoors in the summer and in my small make-shift greenhouse in the winter. I've had more trouble in the house in the winter.

  • 17 years ago

    I'm definitely not an expert - I only have one that I've had for a year. But I do know that I ignore it most of the time. It's about 5 feet away from an east window, so it doesn't get any direct sunlight, but the room stays pretty bright because the windows in that room are large. I don't mist it, but water it probably once every 2 or 3 weeks. Maybe I've just been lucky, but I think it might be one of those plants that doesn't like a lot of attention.

    I love rex begonias! Such beautiful foliage!


  • 17 years ago

    Hi there;

    It took me 20 yrs. :( (no kidding) to learn how to deal with these Babies. Now I have a bunch with some having leaves twice the size of a small hand. :)

    Make sure your soil is nice and light.. I add pearlite to potting soil. You may add some peat and compost never hurts. Just be sure water flows free. Fertilize 1/2 dose every 2 weeks spring through fall. Water less in winter. Lighting as mentioned above is fine. A little sun is OK indoors in the winter, though not for long periods.. I ALWAYS water from the bottom. Preferably in a 1 1/2 to 2" deep plant saucer or bowl. I place a bit of stone or gravel to about 1/2" and set the pot on that. This way, when watered you can see how much the plant takes up. You don't want the plant to sit in the water more than 1/2 hr. I leave just enough water in the gravel that the bottom of the pot is not in the water, but enough water to provide humidity if you have dry heat. If you have a humidifier, you can pass on the wet gravel. I don't use spray misters directly on the plants, just in the general area. I have had a few plants in the past where the leaves spotted, esp. if air circulation is a problem. If you have trouble in the beginning being able to tell when to water, just wait until the leaves just start to droop "a little". Though try not to let it go too much farther to often. They don't really mind once in a while though. Underwatering is always better than overwatering, as you know. :) Then water well. After awhile you'll be able to tell before the droop becomes apparent.

    Another thing I avoid is too big a pot. Even though the leaves can get Big, The roots don't grow as fast and they grow a bit more outward. Too big a pot also hold water and this is not good for Rex. In fact, a pot like you would use for sansevieria, shorter than wide, is ideal and just a bit larger than the rhizomes. (Which are usually, mostly above the soil. Also remember that they are like succulents. If you use a terra cotta pot, this is good. If plastic, you may have to insert into a cashe pot as they can get top heavy. Just be sure it's not left standing in water in the pot. Rex can especially get top heavy in the summer when outside (in part shade) as they really put on growth and sometimes flowers..

    Good Luck and have fun!! Hope this helps! :0