Any rhizomatous can be rooted by leaf - most are easy but some can be difficult. Big succulent leaves are best cut as wedges (which I am finding out after years of trying a whole leaf). Water rooting works well and lets you take all the time in the world to pot up. Perlite works very well.
Here are some I did back in the spring. Hated to throw out all the ugly old leaves so stuck them instead and had many to give away.
HC, you are Butch? May I also address you that way? And I'm curious. What do you do with all the begonias you propagate?
I have B. Cathedral. Do you mean I can take a leaf and put it's stem in water and it will root and make pups? (Are they called 'pups'?)
db, I like single drinking cups for individual cuttings (small cups - 2 to 6 oz) and the aluminum baking pans with clear plastic lid to do a community "pot". I poke holes in the bottom of the pan, fill with perlite about half way or more, water well, stick cuttings, and put a lid on it under lights. I use a similar sized pan as a drip pan. Watch for too much moisture (condensation) which can lead to rot but also too little moisture which can dry the cuttings out quick. Indoors a humidity dome (cover) is very helpful but outdoors it is a judgement call (more to keep falling debris, insects, and rain out). Yes you can start them in winter as long as the leaf is fairly healthy and the room is warm and you have lights (or filtered sun). As for media you can use almost anything but pure perlite is sometimes the best since it is sterile and retains moisture but not so much to cause rot. I've done gravel, sand, potting mixes, and water. Water rooting works best if you cover the entire leaf and vial with a cover (I think this keeps out the germs). It is super easy and you can pot up any time you wish but if you leave in water for months (like I sometimes do) then the plantlets take a lot more time to develop (perhaps because I don't use fertilizer in the water?).
kill, yes you can call be Butch. Do not propagate Cathedral by leaf since I've read that it will not keep its unique pattern - it will revert to its parent. I haven't had Cathedral in a long time but just quoting what I've read on this particular begonia. Do it by rhizome cutting to keep the pattern. But you can root it by water and get pups that way.
Thank you Butch. I was considering propagating some rexes since they are doing well in the aquarium. I'm just happy they are alive - since they never made it in the greenhouse. I don't think they like the hot air heat (and neither do I when I get the bill). I think my love of bottom heat has doomed my past experiments with begonias.
I have kept them in water for months and pot them when I feel like it - no rush. I add water every few weeks if I remember. These vials are under plastic or glass so there is little evaporation and no nasty water (unless a leaf rotted and I did not notice).
It might take the plant a lot longer to get to a mature size when I don't pot it up soon after it roots but then I am in no hurry. I put them in either perlite or a straight mix.
I have barsalouxiae (U434 aka Guatemalan begonia) in water where it has a single pup and has been in the same water for at least four months.
Here is another example of water rooting in a container.
The tall plant is a shrub and is B. serratipetala. Some Asian species shrubs will produce plants from leaf cuttings such as amphioxus and brevirimosa but typically a lot easier to do by stem cuttings. Not sure about serratipetala from leaf. Anyway the idea is water rooting is easy if you cover the entire cup (plastic bag works well too or at least cover the mouth of the cup with plastic wrap or aluminum foil to keep the germs out).
I have planted some plants in straight perlite but usually I lay down a few inches of potting mix in a larger pot, lift the rooted plant in perlite (if some falls off then so be it) and place it on top of the potting mix and fill the remainder with potting mix. Seems to work pretty good.
Here is a favorite way to propagate single begonias - a six oz drinking cup with perlite and a 12 oz cup as the humidity cover. The plant is 'Maid Marion'. If you have a heavy watering hand then cut holes in the bottom cup to make life easier.
Just break off a piece like any cane/shrub; discard the bottom leaves; and put it in a cup of water. Once rooted, pot it up. Again keep the water in a somewhat sterile environment and you won't have to monitor the water for souring (just total evaporation).
I've had my serratipetala in a 29 gallon fish tank for five years. Thought I about lost it due to maidenhair ferns taking over the entire tank. I chopped those back to the ground and also pulled out or cut back to the ground the weedy begonias that sprout easily from seed (parent of wax begonias?). Anyway the serratipetalas have made a great comeback but so have the maidenhair ferns (time for a haircut again).
Here is a serratipetala I started for one of our club members after I potted it up.
That is a beautiful begonia. It's on my list now.
I also root cuttings, especially cane types, in perlite and plant them about the same way you do.
Did you ever say what kind of potting soil you use? If you did I've forgotten.
The last few years it has been Miracle-Gro. In the past it was Jungle Growth but when I couldn't find it any more I switched to Miracle-Gro. Last year I went through at least ten of the largest bags that Home Depot carries and the results were all great. This year I went through about six of the largest bags.
Butch, I searched 'serratipetala' in Home and Garden. No results. Do you have the link?
I have been using Miracle Gro also for a few months now. I think they are doing better in it than in Al's 5:1:1. Maybe a little too much fine pines in his for begonias? Otherwise, his mix has been great for my other plants. Especially oak seedlings.
I used to mix my own media using Hoffman's ingredients - peat moss, perlite, and vermiculite but it was too much dust, too much cost, and too much work. Miracle Gro make breakdown faster than Al's mix but until I see a plant really decline then I leave it alone. There are some begonia folks who change the potting mix out each year so that must make me lazy or stingy or both. That is such a huge committment in cost and labor.
Here is Texas Red Star water rooted and has some little pups on it. The jar is a blueberry syrup jar from Cracker Barrel. Baby food jars and medicine vials also work well.
I contacted the seller last night (after I figured out the spelling) and asked what the plan is since they are no longer shipping because of the cold weather. He has several other begonias that I am interested in buying.
Today is experiment day in the greenhouse. On the yahoo group (I joined last week Butch), Lloyd mentioned that Milstop kills the larval stage of aphids, whiteflies, and some other pests. So, I'm going to spray the whole greenhouse with it, instead of just the begonias. It's a break from the suffoil-x and the botanigard.
Congrats on joining Yahoo. Julie and Mike F. are the ones who got me interested in begonias so many years ago by posting pictures of their fabulous begonias. One in particular was Bashful Bandit. So my first trip to Miami in 2005 is where it all gained steam (sure I ordered from PHOE, GHW, Kartuz a few years earlier but being in greenhouses dedicated to begonias is what really gets the blood pumping) and I got my first Bashful Bandit plus several other gorgeous ones.
Milstop seems fairly effective against mildew which is one of the worst problems I get. Spider mites on colocasias is another problem but they always seem to bounce back vigorously when I move them outdoors.
I don't repot mine every single year either. Maybe every second year or as long as three. Like you said "If it looks good I leave it alone".
Thanks, thanks, thanks, I've got quite a few med bottles. I would have never thought of that if you hadn't mentioned it.