Wendy, aside from the last pic that shows some brown, your Begonia looks healthy. Stems are deep red, and foliage very colorful.

Begonias need humidity. Lack of will cause problems. Placing a large saucer filled w/stones/pebbles and a little water, 'not hitting bottom of pot,' increases humidity, somewhat.

Direct south or west summer sun and/or too much heat will brown leaves and wilt edges. Which direction does window face and how warm is the room?

When you water, drench the rootball, until water seeps out of drainage hole.
Begonias do not like wet feet, so before adding more water, allow soil to dry a bit in-between. Moreso on prolonged grey days and winter months.

After you water, do edges straighten?

Big box stores do not provide a perfect environment for plants.
Plants are usually shipped from FL or green houses with the right climates..light, humidity, etc. Then, the long drive from and to, shocks plants. After sitting in a store, watered whenever an employee thinks about it, causes more stress.
Possibly the reason your Begonia had a few brown leaves at the big box store.

With proper care, your Begonia should do well. It needs time to acclimate, so be patient. Patience is the key, along with the right care and conditions.

Toni

Thanks Toni

I guess I left out the part that I bought it about 2 months ago. I thought I had given it time to acclimate to its new home but it still keeps losing leaves and frustrating me.

That left side is quite bare compared to how it started. It was super full initially. The next to the last pic shows cracking and curling which seems common to it and seems to be the precursor to the eventual leaf loss.

It was deeply watered the day before I took that pic.

Its under fluorescent lights about 10" away and on pebbles. room is on the average to warm side. a bit of west sun end of day.

the foliage is gorgeous and I am about to see flowers for the first time so I really want to help it thrive.

Wendy, were the leaves ripped and/or bent when you bought it?
A torn leaf naturally browns..the only thing that can be done is removing injured foliage. Torn leaves will not heal.

Rotating 1/4 turn, once a week helps. The bare side should fill in if it's getting adequate light. Now that winter is approaching, plant growth slows down. It might take a whle before the bare side fills in.
Since it's flowering, wait before rotating. Chances are buds could drop.

If you're happy with its appearance, 'looks good,' then continue doing what you've been.

Is your house a/c'd or c/a'd? Both reduce humidity. Humidity treys help, but during winter, a humidifer will benefit. They're a great investment. For plants, pets and people.

Those are beautiful leaves!

Begonias (of all type I think?) are susceptible to botrytis. Copied from American Begonia Society site:

"2. CLEANUP: Make sure you keep leaves picked up and remove damaged leaves from your plants. This will go a long way towards disease control. We haven't had much rain (ok none) but with colder temperatures mildew and botrytis can still be a problem if you don't keep dead stuff picked up."

Leaves from other plants, I throw under the plants in the flower bed next to the porch when I take them off, but I make the effort to put Begonia leaves in the back yard somewhere.

You may want to investigate botrytis pics and info to see if you think that may be an issue. They can also get a mildew that I don't know much about. Not really sure which, if either, might be an issue for your plant which does look vigorous (and it's flowering!) except for the few problem leaves. I'm pretty new to Begonias, too.

I think yours is a rhizomatous, which from what I've read (and seen from my brief encounter with them so far) have fairly shallow roots unable to utilize all of the soil space in a deep pot. When you repot, you might look for a pot that is more wide than it is deep. I recently changed one of mine from a 'regular' pot to the drip saucer (about 12" across, 3" deep) that came off of a really big pot. I put holes in it and now it's a pot. Now the chunks of rhizome/root are farther apart and the leaves have more elbow room. It's not taking so long to dry out.

Hi Wendy,

Very pretty leaves, nice colors. Is it possible that the mix has become compacted & hardened, which would prevent the plant from drinking properly?

I only grow a couple of Begonias, but I'm friendly w/ the head of the NYC Begonia Society (called the Knickerbocker Society). In the 10 yrs+ I've known her, heard her speak & swapped plants w/ her, I've never even heard her mention Botyris.

Purple, while I hear you're being cautious, (IMO) it's far more likely problems of watering, mix, culture than disease. I do suspect the rootball has hardened off or there's another drainage problem.

I'd hate to interfere w/ the blooms, but maybe when they're done, I'd unpot to check the roots.

I don't know either. From reading, I thought that's why some of my plants were getting brown spots. The ones my neighbor pulled out of buckets of stinky water to give me. I don't know how prevalent it is, but the snippet from the thing I linked made it sound kind of like powdery mildew, rarely fatal unless there's something primarily wrong with a plant, like you mention, with the roots. Just a nuisance on a healthier one. Doesn't seem to be spreading around, whatever it is on my plants in question.

Begonias can get thrips too.

Wasn't trying to diagnose the plant 'cuz I don't know. Just informing. Those curled edges just don't look right... or do they? I don't know.

I was told this is a rhizomatous Begonia, they look like close relatives.

when in doubt, cut it back, repot with new soil and start over. In 6 months time you will be very pleased! :)

Hi, I think that is 'windowpane' begonia, cant recall the latin name . . . .
if it is, it is a cane begonia. Mine loses leaves in fall, and I pretty much cut it back, and root some of the cuttings.
i cut mine back hard each year. In spring, it begins to fill out again, and I also have extra plants from the cuttings I took (I give them away or stick them in pot with the original plant)