They're pretty easy to start. I used to start them in invidual pots (3-4" or so, whatever they fit in) and then transplant into the large pottery on the patio at planting out time. Plant the sprouted and unsprouted the same way. They should still sprout at 65 degrees, though they would sprout quicker if warmer. Can you put them near a windowsill - maybe a small table or even a chair by the sill so the sun filters down on them? That would warm the soil and the light would stimulate them to grow, too (I start my bulbs by the window - there's not a lot of sun, but enough). Don't water too much until you actually see leaf growth - keep the soil moist but not overly so, the tuber has to put on root growth first, and if no root growth and the soil is too moist, it may rot out on you. If they start to get leggy if not enough light, just pinch them back, same as you would any other annual.

I think that is why they are more like annuals here due to our high temps but I still buy a few every year and don't worry about tossing them. Well I tossed a pot of Bonfire that I presumed dead on the compost heap last spring and later in the summer it did this! I doubt it survived our winter but I will continue to look for signs of it. Oh, those cats! Whatever you do, don't go away for a weekend and let one of your cats locked into a bedroom without water, food, and a litter box! We had 3 cats at the time and checked everything, closed the bedroom doors and had an extra litter box and a food and water silo in place. Whoops, when we got home we had closed the extra bedroom door with our little female in that room for 2, maybe 3 days. She was fine but the sleeper sofa wasn't. Well, cats are much easier to take care of than dogs. And dogs in the garden are a lot more destructive too. A squirrel knocking over small pots is nothing compared to a 90 pound dog chasing said squirrel among hundreds of pots or same dog digging a hole to China going after a chipmunk. I won't even talk about the urine damage to our lawn this winter (our oldest dog cannot make it up and down stairs any more so out to the front yard on a leash). Ah, the joys of pet ownership? My motley crew - Max the old man and Duke the 10 year old puppy aka troublemaker.

Sorry, It's not a tuberous. It's a cane begonia

Linnea, Next fall, let your begonia be touched by frost. Much like dahlia, the frost will kill the foliage. That's your cue to bring them in --- to a garage or other place, where they have the stalks removed, flowers go too, and let them dry for a couple days before they go into storage. Just like geraniums, they can be stored where it is cool, dark, and dry. There left to spend the winter. No sprinkling, no water of any kind, no light which can initiate growth, no heat...just cool, in the range of 38 - 50ºF.... AT this time you might make note of the color of the flower on each bulb so that next spring, you can plant accoridng to that wish. If the bulb doesn't have a particular look showing which side is up, put them on a shelf designating which end had the roots. Most times though you can feel the concave end---that's the top. Old roots too can give it away. Now I believe the frost treatment allows the bulb to send its starches and sugars back down into the bulb....much like why we let the tulips wilt on the vine, to do the same. The next spring, the bulb has all the energy that wasn't destroyed by removing the foliage too soon. If the begonia goes inside to enjoy the bloom for as long as it will, then do much the same, remove the foliage, let it dry, then store it where cool. As far as why the foliage wilted, the distinct temperature change from out of doors to indoors, is probably what caused it. Keep cutting back the water and let the bulb use less and let it go dry.