Hi, i am fairly new to begonia growing. This is my first one, which i got in february. It has been growing like crazy, i repottes it in may, and since then it's now blooming for the second time. I water it 1-2 times a week, when i feel that the dirt is dry. We only have windows to the east side, have direct sunlight only in the morning, after that, no disrest sunlight, but enough light. I used to keep it on top of a printer, because that window gets the most sun, and moved it to a shadyer window a week ago. The ends of the leavs started drying out a couple a months ago, but a couple a weeks ago there started to appear some discolorations and dry spots in the middles of quite young leavs. Why could it be like that? Maybe because when i water it in the sink, the water gets on them? Also, almos from the start most of the leaves get little holes and cracks when sprouting.

hole sand cracks in leaves are likely from low humidity (may be it's now THAT low, but not high enough for the plant). if the plant is small enough try tenting it at least in florist clear open sleeve. it can be open on the top and be in partial sun too : the sleeve will increase humidity sufficiently for leaves not to crack.

Leaf damage is part of nature and begonia leaves are prone to easy injury which can lead to infections and scarring. The brown spot looks like a fungal infection (probably mildew). Leaves come and go but you do not want mildew to infect all the leaves as this can kill the plant or set it back significantly. I've found that the big polka dot begonias are quite prone to mildew (indoors). Cutting back on watering indoors has helped a lot on my own begonias. Anyway, cut off badly damaged leaves and discard, spray if needed with some kind of fungicide, give adequate light, and water as needed.

yep, I would spray with anti-fungal too before tenting. as tenting might increase the rate of spread if it's fungal. unfortunately in my case I have found that begonias grown indoors (as all of mine are) have very tender leaves and they will wither and die from fungicide. but new growth should replace them. even with dying leaves it's better to spray then not.

I put one spotted cane outside and after 1 month it toughened, BUT! I found mildew spots on it. I sprayed it and it was ok - it did not damage the leaves.

Huh? "...wither and die from fungicide... It's better to spray then not" That sounds contradictory.

If you do decide to spray, use some fungicide that won't harm your plant. Only use it if the plant is horribly infested with mildew. Cut back on watering first thing and see if that helps. Remove infected leaves to reduce a breeding ground.

Mildew spores are everywhere and just waiting for perfect conditions to grow and reproduce (usually cool, damp weather). Don't give it those conditions (if you can).

>>Huh? "...wither and die from fungicide... It's better to spray then not" That sounds contradictory.

when I spray my rexes with wide-spectrum fungicide (that I have and use on all kinds of indoor and outdoor plants) rexes yellow and drop all leaves within days. and what regrows slowly is smaller and weaker. But still it's better then allowing fungal disease to eat them up completely. what's contradictory? it saves them, but they are weaker afterwards.

But B.maculata has stronger leaves then rexes, I think.

I don't have problems with mildew/fungal on begonias indoors (when they are kept strictly indoors and are my propagations from leaves). only when they've been outside , including new nursery plants.

anyway, I am very cautious now with spraying rexes. But B. maculata is a different story, of course.

What fungicides are you using?

i'm not at home at the moment, so can't give you an exact label. but it's something wide spectrum , and not sulfur (for all fungal: which suits me, as I am an apt city dweller with limited storage space and very few garden shops ;(. I used it many times on all sorts of tropicals indoors and out. Hydrangeas outdoors also dropped leaves from it.

perhaps it's too strong and I should try half dosage.

Can it be fungal infesction, even though there is no fur and they are just dry spots?

Fur? What's that on a plant? Like a fuzzy leaf?

It was more than likely a mildew infection at one point. "Was" being the operative word. That doesn't mean that the spores aren't still lurking around on the surface of the leaves, soil, stems, pot, and anywhere else. Bathrooms, basements, and garages are infamous for mildew (damp, cool spots).

Leaves are expendable but when you start seeing mildew on the canes then you really need to be on the defense to get it under control else it will eventually set back the plant or kill it. I saw a Lynda Dawn on my porch years ago develop mildew (or some other fungus) and I did not act in time - it killed the plant in a few weeks.

There are many safe(r) remedies to treat mildew/fungus such as Neem oil, Milstop, and I switched to Orchard Spray which is pyrethrin (insecticide) and sulfur (fungicide) and while mildew is always present and can rear its ugly head, I have a lot more success by being a little more proactive. Watering when needed as been a boon for me.

Begonia Sinbad is notorious for mildew in fall/winter. Last year I barely watered it and no spraying. It came out this past winter with flying colors whereas in the past it would probably be dead or close to it.

It's the first time for me to actually grow a plant, until this year I wasn't really into them, so i don't know how mildew looks. I google searched it, and in most photos it looked whitish and furryish. :D I don't see anything like that on my Maculata of my Rexes. My begonia rex has some wiltered leaf edges, but I think itvs because I underwatered it for a little while, until I got the hand of it. Now the ones that don't get as much sun have wonderful big leaves, and another one, that is by another window dorsn't look as good. I will probobly buy some fungicides just in case. :)

It is a learning process that they don't tell you about until it happens. The internet has really helped things. In the past it was friends, family, and whatever books you could find (and there wasn't much out there for begonias).