Most begonias fall into one of two major categories: fibrous and tuberous. I'll write mostly about the tuberous ones today, as it is time to get them protected for the winter.
Fibrous begonias, also called wax begonias, are grown as annuals here in the Rogue Valley. They are brightly colored bedding plants with a mounded shape, often no more than a foot tall, with stiff, glossy leaves that are green or bronzy green. They like full sun or dappled shade and are nearly covered with small white-, pink-, rose-, red- or salmon-colored blooms.
Tuberous begonias, on the other hand, have much larger and more showy blooms, available in the same general colors as the fibrous variety, and are either upright or hanging in their growth habit. Their leaves will burn in the sun, so they need shade, or only morning sun, in order to thrive. But they need some special care now so that they will bloom for you year after year.
A winter dormant period is needed by the tuberous kind, determined by the weather and day length. This is part of the normal life cycle of the plant, so it does not work well to put them in a pot and bring them indoors to continue blooming for the winter. Some of mine are still blooming despite our chilly nights, and it is tempting to just bring them inside, but I remind myself that they need a rest, as do all flowers that grow from a tuber, bulb or corm.
The time to dig the tubers is after a frost has ruined the foliage. Dig up the entire plant and gently remove all the soil from the tuber and any roots. Do not delay this task too long, as a hard freeze could hurt the tender tuber, which is planted very shallowly. Remember to label the plants or tubers so you will know what colors you have next spring.
This process should be followed whether your begonias are in the ground or in a hanging basket or other container. The soil in the containers should be renewed next spring anyway so that your tubers will have a fresh start.
Lay the entire plant in a warm, dry area for several days to thoroughly dry the tuber. If a frost is predicted during this time, bring the plants into a shed or garage to finish the process. Once the tubers are dry, the stems should detach easily. If they don't, they aren't ready, so let them dry a bit longer.
Check the tubers for pests or rotted areas. Often, even if there is some damage to a tuber, it can be cut out and dusted with a fungal powder and it will be just fine.
I recommend putting each tuber in a separate, small, labeled, paper bag. Several bags can then be placed in a cardboard box for storage in a dark, dry, cool place. This way, if you have any fungal problems, the offender can be removed before it infects the others. During the winter, check the tubers periodically for the same reason.
Next spring, when you see the little pink buds forming on the top of the tubers, you will know that the begonia's rest time is over, and it's time to replant them for another beautiful show of flowers all summer.
Coming up: "Growing Bamboo" will be the topic of a class taught by Thielsen Lebo of Lebeau Bamboo from 7 to 9 p.m. on Wednesday, Nov. 14, at the Southern Oregon Research and Extension Center, 569 Hanley Road in Central Point. The cost is $5. Call 541-776-7371 for information.
Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. Email her at firstname.lastname@example.org.