Brad Thompson | Brad’s Begonia World
Information and tips so you can formulate a plan that works for you and your growing conditions.
There is no one method to follow when growing begonias or for how you winter them or bring them indoors.
Many Southern Growers will be following some of the methods above, especially if they don’t live in frost free areas. Likewise, many Northern Growers with be able to use some of the Southern tips to help them preserve struggling plants.
Besides having a much longer growing season overall, southern growers in some areas are even able to keep their begonias outdoors all year round. Even in those areas, there are some precautions and procedures that can be taken to assure the plants will survive the winter. In most southern areas, although it doesn’t freeze often or ever, they still have to contend with cold, wet weather. As most of you know, cold and wet are two conditions begonias hate with a passion.
So, what can you do about it? One procedure that I practice in my yard , I’ll call “crop rotation”. As the seasons change and the available light changes different begonias are moved to take advantage of the best light. In the winter, more delicate varieties are moved either into areas that have good winter light or that are more sheltered. Since the only way you can solve the “cold” problem is by constructing a greenhouse most of you will have to settle with solving the “wet” problem. Begonias can stand cold temperature much better than they can stand wet feet. Sensitive begonias can be moved under awnings or porch roofs, etc. to keep them from excessive rain. Some growers even go so far as to cover their shade houses with plastic sheeting. That will keep all the begonias dry. You will have to consider what your neighbors will say when it happens that you are standing outside watering your begonias in the pouring rain. If you choose to totally enclose the shadehouse with plastic, including the sides, you’ll have to take into account that there will be warm winter days. Your winter enclosure probably won’t have heat or cooling. I would suggest leaving at least one side open or that you can close at night or on cold days.
Many growers don’t have the option of covering or rotating because of limited space or limited time. Those growers have no choice but to just leave the begonias where they are. There are still things you can do. The most important thing is correct pot size. Do you have any plants that seem to stay wet all the time? Those plants are either over potted or root damaged or both. If they’re staying too wet now just imagine how wet they’ll stay this winter in the rain. Now is the time to correct the problem before it gets worse. Gently lift the plant out of its pot. You will see that some or most of the soil stays in the pot or falls off the plant when you lift it out. This shows you the plant is in too large a pot or that the roots have died to the point that they don’t hold the soil together anymore. In the spring, when you are moving plants up to larger sizes, it’s expected that many will be growing into those larger pots. During the winter, however, these plants will only decline furthur. The solution is to remove all the loose soil from the plant. Once the soil is removed, find a pot that is only slightly larger than the remaining rootball. Replant the begonia into the new pot. Next spring you will usually find the plant fully recovered and ready to move back up to a larger pot again.
If you live in an area that has an ocassional frost some years, you should have precautions ready. Many growers save old sheets to cover the plants with if a frost is expected. Some also save large cardboard boxes to totally enclose plants with. Plastic sheeting can be used but if you also have rain, you can break plants. Plus, when the sun comes out, many plants can be burned by the heat through the plastic. A newer innovation is a type of plastic that has microscopic holes in it so it allows air, heat and water to pass through it but still protects from frost. I’ve heard from growers that have used it, that said they were able to keep the covering on for a couple of weeks without the daily removal and the plants were fine. This would be a big benefit over the other coverings which you will have to remove during the day and replace every night during cold spells. I can’t tell you the exact name of the plastic but it is available from most mail order seed companies, such as Parks Seed.
Though I haven’t tried this myself, I have heard from growers who live in areas with some frost, that trim back their begonias and mulch heavily with straw or a similar mulch. If you have found that you live in an area where the frost is just enough to completely freeze most begonias, you might try the mulching. You wouldn’t have anything to lose. When you trim back the plants, the cuttings can be taken indoors for the winter. The roots can remain in the ground under the mulch.
With all the different variables across the country, I can’t specifically tell anyone exactly what will work in their area. The suggestions above are to help you experiment in your yard to see what will be successful for you. I would appreciate e-mail from anyone that would like to share their winter experiences for future reference. Use the e-mail link on the home page.
The following advise is from a talk given by Graeme Peake at the Begonia Festival and Show, Auckland, in February 2014.
• When the potting mix is dry, lift the tuber, trying not to break the larger roots.
• Sit the tuber aside leaving the old mix still attached for more drying.
• Brush the old mix off carefully, not damaging non dried roots.
July to Oct Storage
• Dip tubers in 10% Demestos or 5% Janola solution or in straight Methylated spirits and dry. Dipping helps control/minimise storage rot.
• Store in a cool, dark place, they can be wrapped in paper or buried in an inert medium, eg. sand, sawdust.
• Inspect tubers for rot regularly. Light weight tubers or ones that sound hallow when flicked might be rotten inside.
• Dehydrated tubers, wrinkled skin, can be sprayed with a little water.