Q: I had spectacular pots of dragon-wing begonias last summer. I couldn’t bear to let them die, so I brought them in for the winter. They are now very leggy and not blooming at all. Should I cut them back? Should I start new ones from cuttings? If so, what is the best way to do that?
A: Dragon-wing begonias are a wonderful plant, aren’t they? Unlike a lot of plants grown as annuals — including some other types of begonias — they can be overwintered as houseplants. The trouble is, it’s hard to give them enough light during our dark winter months. Even in a sunny window, they may become leggy, as yours have done.
Yes, you can cut back the existing plant, but you might want to wait until March in hopes that it will fill out and be bushier when you want to take it back outside in May. (Remember to introduce it to the outdoors gradually, just an hour a day at first, out of direct sun, gradually increasing the time and sun and wind exposure. It has become a wimp in your house over the winter and needs to toughen up again.)
You can also start new plants from the cuttings.
Starting plants from cuttings works the same way for many plants — including geraniums, ivy and many other houseplants.
We don’t recommend starting them in vases of water. Although it’s possible to get some plants to root in water, sometimes the roots they grow won’t “take” when you put them in soil. You’re better off starting your cuttings in a soilless medium such as coarse sand or a mixture of peat and perlite.
Put the mix in containers that drain, and use a pencil to make a hole in the growing medium in each container. Then, take your cuttings: Cut a piece five or six inches long from the tip of one of your leggy stems. Make sure it has at least a couple of “nodes,” spots where leaves are growing or where there used to be leaves. If there are still leaves on the bottom nodes, remove them so that you have a couple of inches of bare stem to poke into your pencil hole. You can dip the cut end in rooting hormone (available from garden stores), but it’s not essential. Plant your cutting a couple of inches deep and firm the growth medium around it.
Keep your cuttings moist but not soggy. Provide bright indirect sunlight or grow them under artificial lights. Once they’ve developed roots, you can repot in potting soil.
Send your questions to email@example.com.