Although often sold as half-hardy annuals, most Begonia varieties are perennial. Here in the UK, they are not frost-hardy and will die during cold, damp weather. The following article will give you advice on overwintering Begonias. I will cover both bedding and tuberous varieties and how best to protect them.
How to Store Begonias Over Winter & Why
Both tuberous-rooted and rooted varieties can be overwintered in a cool, dark, and dry place. Doing so is especially favourable, as both mature Begonia corms and well-established rooted varieties produce bigger and stronger plants for next year. I like to leave my tuberous varieties in their pots or hanging baskets and place them in the garden shed during the winter months. Every year, I lose a couple of Begonia tubers. Tubers are prone to attack by vine weevil grubs during the growing season. This weakens or even hollows out the tubers, causing them to rot during the winter. Fibrous Begonias are best grown indoors on a bright, warm windowsill.
Fibrous Rooted Begonias
Fibrous-rooted Begonias such as ‘wax’, ‘Angel’ or ‘Dragon winged’ may be pruned into a manageable shape and taken into the house or conservatory during the winter. They make attractive pot plants. I normally re-pot my fibrous-rooted Begonias before bringing them in. I do this to avoid introducing stowaways such as slugs and grubs into my home. Avoid draughty areas of the house to get the most out of your bedding Begonias during the colder months of the year.
Overwintering begonias (Tuberous Rooted)
Although many have tuberous roots, the majority of Begonia varieties are very tender and incapable of surviving the UK winter. They will require a period of dormancy in a cool and dry place. If you prefer to overwinter your potted Begonias by keeping the rhizome (or corm) in the same pot, then ensure you replace most of the compost during early spring. Failure to do so will result in poor growth and fewer flowers. Begonias will also need feeding when they start to produce their first leaves. If you want to know more about how to store Begonias over winter in the UK, then read on.
Getting started with overwintering Begonias:
- Before the hard frosts arrive, dig up the entire plant while the foliage is still attached. Take care not to damage the Begonia tuber during this process. Doing so may cause your Begonia tuber to rot and die. Shake any weevil grubs out.
- Remove any diseased tuber parts with a sharp knife.
- Allow it to dry for one week in a frost-free and sunny location.
- By gently teasing the stems away from the tuber, you can remove the foliage. Again, take care not to damage the tuber. Begonia rhizomes are delicate and easily scratched.
- With your fingertips, gently clean away any excess soil or compost.
- To prevent rot, I recommend dusting your Begonia tuber with sulphur powder.
- Tubers should be stored in a clean cardboard box. Space them evenly apart and place the box in a dry, frost-free, and dark cupboard until spring.
I recommend that you check on your overwintering Begonias regularly. This ensures that they remain dry and rot-free. To reduce the risk of infecting other tubers, remove any that have started to rot. If in doubt, set aside suspect tubers. Begonia tubers can appear dead at times, only to successfully re-sprout in the spring.
Note: If you live in a particularly mild area of the UK, you might want to try leaving your Begonia tubers in the ground over the winter. Cover them with straw, used compost, or leaves until the threat of frost has passed. In my coastal garden in Devon, I have several tuberous Begonias. They appear to thrive even when left in the ground during the winter. This approach, however, is not without risks. I am confident that a harsh winter will eventually kill them off. But my Begonias have been in the ground for 6 years and are doing well.
Begonias: when to plant
Protect your overwintering Begonias from very low temperatures and frost by adopting the following process:
- Bring your Begonias out from their ‘overwintering’ during the month of April.
- Place tubers hollow-side-up and individually in pots or rows in trays of fresh general-purpose compost.
- Cover with 1 cm (1/4 inch) of compost.
- Place your plants in a shady spot in a well-ventilated room, frost-free conservatory, or greenhouse. They will need plenty of light, but I’d recommend keeping them away from direct sunlight. I place my Begonias on a lower tray under the bench in my greenhouse. They get plenty of morning sun, but very little during the day.
- Do not let the compost dry out. Spray or gently water. Ensure that the compost is well-drained.
- Treat your Begonias with a high-potash feed as soon as flowering starts. Tomato feed such as Tomorite is ideal.
- Remove dead flowers and foliage to encourage more growth and prevent rot and disease.
- Don’t forget to enjoy your Begonia plants! They are very versatile, and most varieties can cope with some level of shade.
Begonia tubers: Dividing
- Plant the Begonia tubers in March or April. For the best results, grow at a temperature of about 18°C (64°F).
- Fill a tray or large pot with 3–4 inches of moist, gritty (or sandy), free-draining potting compost.
- Place each tuber on the surface of the compost. Ensure that the depressed side is facing up. Space them at half-inch intervals at a depth of 1 inch.
- Once growth begins, divide each tuber with a sharp, sterilized knife. Ensure that each section has at least a single bud and a root below it. Dividing each tuber into quarters is ideal.
- Before potting on, allow each sliced Begonia tuber to heal for a couple of hours.
- Place each segment into individual pots of firm compost. A good-quality, multipurpose compost will suffice. Ensure that the tops of the tubers are level with the top of the compost.
- Keep the compost moist, but do not overwater.
As well as overwintering Begonias, I also overwinter Dahlias. Please visit my guide to storing Dahlias over the colder months.
Frequently Asked Questions on Overwintering Begonias
Yes, Begonias can be overwintered in pots. Fibrous varieties can be kept as houseplants, whereas tuberous varieties should be left dormant in a cool, dark place. I always leave my fibrous, rooted begonias in their pots over winter and place them outside once the risk of frost has passed. Don’t forget to harden them off!
A cool but frost-free area that is dry and dark is ideal. Individual paper bags can be used to store them. A garage or an unheated room in the house would be ideal.
Tuberous Begonias should have their foliage trimmed and discarded. Begonias with fibrous roots and rhizomatous roots do not die back once a year. Instead, tidy them up.
Tuberous Begonias will not tolerate hard frosts, and temperatures below 50 degrees can harm any Begonia.
I am new at this gardening thing thing. I was told I can ‘tent’ my bagonia to save it over the winter. Is it that simple. I live in Bellingham Washington. It is still before the frost.
Barbs
Hi Barbara,
I haven’t heard of ‘tenting’ begonias, except perhaps for propagation purposes. I’m not too sure what kind of weather you have in Bellingham – how cold it gets or general humidity, but I would suggest that digging up and over wintering your begonias is a very safe option. It also gives you the opportunity to perform a little health check on your plant’s tubers. I found a few grubs in mine this year – now I’m glad I checked.
If your begonias are fibrous rooted, then you can either dig them up, trim them back and store as house plants over winter, or take cuttings and keep in a warm spot in your house. Most begonia varieties easily take from cuttings – hardly any labour at all.
I hope this helps.
i’m new at geraniums and begonia over wintering. i have kept plants as indoor but have many pots and not enough room for all so have decided to dryroot them. i am zone 6 (ontrio canada) have done much research and have come to the conclusion that dry root is the best method ?? i have both geraniums and begonias. any advice would be welcome.
Hi Diane. The method doesn’t really matter, as long as you do the following to over winter your begonia tubers:
* Keep in a frost free place.
* Keep dry.
* Check on them every now and then to ensure aginst fungal infections or pest infestations.
* You can pack them in dry compost or in newspaper.
Let the frost just touch the begonia plants before removing the tubers – this will allow for some of the nutrients to return back to the tuber. Don’t leave them in the ground for too long or you will loose them! It’s also a very good idea to label each tuber. I forgot to do this one year and had trailing begonias in tubs and erect forms in my hanging baskets!!!
Last year, I left my tubers on my windowsil to dry for a week. Once dry, I tapped away the remaining compost and found and removed several vine weevil lavae. I’m glad I did this now as the weevils would have had a begonia snack over winter!
Always be careful when cleaning a begonia tuber. They may look as tough as old boots, but they are not. The skins around the tubers are very thin and can easily peel away increasing the chances of fungal infection.
My husband has stored my begonia tubers in newspaper, in an airtight polystyrene box.
Is this OK.
I think that sounds like a reasonable why to store them. Just make sure you check them every couple of months to ensure that they aren’t going rotten and keep each one separately wrapped. Thanks – a good suggestion.
Hi James last year I left my tubers in the tubs in which they had spent the summer months. Letting the compost dry out and storing in a frost free greenhouse.
This spring they came back to life giving me a flying start and enabling me to take fresh cuttings for rooting I then replanted the original tubers/plants into fresh tubs and compost
I may have been lucky but I will try again this year to see if it works again, of course correct labelling is important at the time of storing
To be honest with you, I think that this is the safest approach – keeping them in the tub or container they originally grew in. Be careful though – a sharp frost could still do major damage. A cool greenhouse or shed should be a safe environment for most winters. I would also recommend avoid watering. Don’t let them totally dry out, but a light misting over the compost if it dries out should do the trick.
Hi this will be the first time that I have had begonia tubers and recommend putting them in sulphur powder, which one do you use as when I look on line, there seems to be all different ones. I also have some dahlia tubers which I will be taking up and storing, should I use sulphur powder on them before storing ? I live in Liverpool.
Thanks for any advise, stay safe
Regards
Pat
Hi. I’m new to storing begonias. Do I have to wait until the plant has died back before storing or can I clip off the foliage then dry and store the tubers
My begonias are in outside pots currently. They still have flowers and we haven’t really had frost yet (in November in UK) Should I bring them indoors indoors or will they be ok in the garage over winter? Should I still put things over compost to keep them warm-ish?
Hi Pat, Yes, a light powdering is good, mostly focussing on the areas of the Begonia tubers that have cuts or are damaged.
Either should be fine. Just handle with care. Also, look out for any grubs hanging around the root. This is why it is good to clean the tuber before storing. Just do so with great care. They are easily damaged.
Sorry for the delay. Hopefully, you have brought them in. Some begonias have tubers, some fibrous roots and some are non-herbaceous. How you treat them will depend on these. An non-herbaceous variety should be taken into the house and left in a bright spot. The others can be stored in a dark, frost free environment. I hope that helps for next year 🙂
Hi, What is the best treatment for the vine weevil grubs ,Iam pestered with them every year….many thanks
Sorry to hear about your vine weevil problem. They are a pain. I would firstly opt for the most organic approach; perhaps incourage birds, frogs, toads, hedgehogs, and shrews. They all eat vine weevils. Also, before planting, check the roots of your plant thoroughly. I hope that helps.