How to Store Begonia Tubers over Winter

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How to store begonia tubers over winter comes down to a short sequence: dig the tubers after the first killing frost, let them cure in a cool, dry place, pack them in dry or slightly moist material, and keep them between 40 and 50 degrees Fahrenheit until spring. The university pages below agree on the timing and on that temperature range. They differ on how to handle the stems and on how moist the packing should be, and this guide shows where those differences sit.

Quick answer

• Dig tuberous begonia tubers within a few days of the first killing frost, then cut the stems back to about one inch above the tubers.
• Cure the tubers in a cool, dry place for two to three weeks, then shake off the remaining soil.
• Pack them in dry peat moss, vermiculite or sawdust, and hold them at 40 to 50 degrees Fahrenheit without letting them freeze.
• Check the stored tubers through the winter, remove any that rot, and start them indoors in late winter.

Why frost sets the timing

Tuberous begonias are tender perennials, and the tubers are the part a gardener keeps. The NC State profile says the plant is hardy in USDA zones 9 to 11 and usually flowers for four months, from early summer until the first frost. The Missouri article notes that many tender plants are not winter hardy at its latitude, and says their storage structures should be dug soon after the tops are killed by freezing temperatures. A garden outside zones 9 to 11 should therefore plan to lift the tubers each fall.

Timing is the first decision. The Iowa State guide says to dig tuberous begonias within a few days of a killing frost. The Missouri article is stricter, saying they should be dug immediately after the first killing frost. The two pages point to the same event and differ only on how long a gardener can wait after it. Following the stricter Missouri wording removes doubt about the window.

The NC State profile gives a second route. It says to dig the tubers before the first fall frost, or to move plant containers to a frost-free location. That route suits a gardener who grows begonias in pots, since the container can be moved indoors before frost arrives.

Water is the other early step. The NC State profile says to taper off watering in fall when the leaves begin to turn yellow. It gives no number of days, so the yellowing leaves are the signal to watch. For the fall work on the bed itself, see our guide to preparing raised beds for winter.

Lifting the tubers with care

Dig carefully, as the Iowa State FAQ advises, and leave a small amount of soil around each tuber. The rest of the soil comes off after curing, so the tuber is not handled more than it needs to be while it is still moist from the ground.

After lifting, the stems need attention, and here the two sources differ. The Iowa State FAQ says to cut the stems about one inch above the tubers before curing. The Missouri article follows another order. It says to leave the tops on while the tubers dry in a warm, dry location, and to remove the tops after about 14 days.

This is the clearest disagreement between the pages. Both routes leave the tubers without their top growth before storage, so the choice mostly affects how the tubers are handled while they dry. Neither page explains why the order matters, and neither compares the two results.

Curing comes before storage

Curing lets the tubers dry before they are packed. The Iowa State FAQ says to place them in a cool, dry area for two to three weeks. The Missouri article says to use a warm, dry location for about 14 days. The two pages agree on dry air and on a drying period of about two weeks. They disagree on temperature, cool for Iowa State and warm for Missouri, so the guide does not give one figure for the curing space.

After curing, the Iowa State FAQ says to shake off the remaining soil. The Iowa State guide to tender perennials also says to remove any rotting, soft, or dried-out bulbs that develop. That instruction covers storage in general, but the guide’s table lists tuberous begonia among the tender plants it covers, so it applies to these tubers as well.

Packing material and storage temperature

The packing material holds the tubers steady and controls moisture. The Iowa State FAQ describes a layer of peat moss, vermiculite or sawdust in a small cardboard box, with the tubers laid on that layer and covered with more of the same material. The Iowa State guide to tender perennials lists cardboard boxes, plastic crates, paper bags, mesh bags, or containers of peat moss, shredded newspaper, sand, or vermiculite as storage options.

Temperature is the number to keep in mind. The Iowa State FAQ gives 40 to 50 degrees Fahrenheit for begonia tubers, and so does the Missouri article, which says the tubers should be stored between 40 and 50 degrees F. The Iowa State FAQ adds that the tubers should not freeze.

Moisture is where the sources differ. The Iowa State FAQ describes dry peat moss, vermiculite or sawdust, while the Missouri article describes the same materials as slightly moist. The NC State profile says to dry the tubers and cover them with a dry medium such as peat, wood shavings or pearlite. The Missouri article offers a tiebreaker: as a general rule, it is better to err on the dry side rather than the wet, because excess moisture in storage can be very damaging.

Where to keep the box

The storage spot matters as much as the box. The Iowa State guide to tender perennials says most tender perennials need temperatures around 40 to 60 degrees Fahrenheit, and that some prefer the cool end of that range while others prefer the warm end. The guide does not single out a figure for begonias, so the 40 to 50 degree figure from the FAQ and the Missouri article is the better guide for these tubers.

The same guide lists an unheated basement, a root cellar or a cool spare bedroom as possible spots. Normal interior temperatures are too warm, according to the guide. A garage is a common choice, but the guide notes that most garages, even when attached to the house, can get below freezing during extreme weather, which makes them too cold for survival. Checking the spot with a thermometer before the box goes in is a simple way to confirm it.

If no spot in the home stays within the range, the guide says it would be best to grow these plants as annuals instead of perennials. That means starting new tubers each spring rather than storing the old ones. The guide does not give cost or effort figures, so the choice depends on the space and time a gardener has.

Winter checks

Plan on regular checks. The Missouri article recommends checking stored material during the winter months and removing any that might be diseased. The Iowa State guide to tender perennials says to check on bulbs periodically throughout the winter, and to remove any that rot.

Moisture needs attention during these checks. If the packing has dried out, the Iowa State guide to tender perennials says to lightly moisten it, and to be careful not to overwater, since overwatering leads to rot, mold and fungal growth. The NC State profile adds that too much water can cause tuber rot.

The sources do not describe how to tell an early rot from a healthy tuber by sight or smell. The practical rule from the guides is to remove any tuber that is rotting, soft, or dried out, and to leave the others undisturbed. The Iowa State guide to tender perennials also says to leave the storage organs intact until spring, because any injury incurred prior to storage will increase the chances of rot.

Replanting in late winter

Replanting is the last step. The NC State profile says to store the tubers until late winter, and to start plants indoors about 2.5 to 3 months before all threats of frost are over. It says the plants may be replanted outdoors, or the containers brought outside, after the last frost. It also suggests planting the tubers shallowly, in groups of three or four per container, or spaced 12 to 18 inches apart in the ground.

The sources give timing in relation to frost, not as a calendar date. A local last-frost date turns that window into a planting day. For the soil side of spring planting, see our guide on how much soil a raised bed garden needs.

Mistakes the sources point to

• Letting the tubers freeze, which the Iowa State FAQ warns against.
• Storing them too wet, since the Missouri article says excess moisture in storage can be very damaging.
• Skipping the curing period, which the Iowa State FAQ and the Missouri article both describe as a drying step.
• Leaving the plants watered after the leaves yellow, when the NC State profile advises tapering off watering in fall.
• Injuring the tubers before storage, because the Iowa State guide says injury raises the chance of rot.

How we chose

This guide uses the storage steps in university extension pages and in a plant profile from a land-grant extension program. We opened four pages on 2026-10-23, read their text, and kept only the steps that appear in that text. Two of the four are storage guides for several tender plants, one is a question-and-answer page, and one is a plant profile. Each step is tied to at least one page. Where two pages disagree, both versions appear.

The Missouri article has a web address that shows 2008, so its advice is cross-checked against the other pages wherever they cover the same step. We did not rank the methods, and no product is recommended. Packing materials are named only because the pages name them.

What we could not verify

The four pages do not show how these steps work in a specific house, garage or basement. None of them gives a humidity figure for the packing beyond the words dry and slightly moist. The timing depends on a killing frost, and the pages do not give a frost date for any region.

What the sources do not say

The NC State option of storing containers in a frost-free location does not give a temperature or a watering schedule. The pages do not give a size or weight for a typical tuber, so the guide has no sizing advice for the box. The Missouri article’s 40 to 50 degree range is for begonias, while its caladium figure is about 60 degrees, and that figure does not apply here. None of the four pages compares how stored tubers and tubers left in the ground perform the next season.

Frequently asked questions

When should begonia tubers be dug up?

Dig them within a few days of a killing frost, according to the Iowa State FAQ. The Missouri article says to dig them immediately after the first killing frost. The NC State profile offers a second option, digging before the first fall frost. All three link the timing to frost, not to a date on the calendar.

Should the stems be cut off before storing?

The Iowa State FAQ says to cut the stems about one inch above the tubers. The Missouri article keeps the tops on while the tubers dry, then removes them after about 14 days. Both leave the tubers without top growth before storage, but the order of steps differs.

What temperature is right for storing begonia tubers?

Both the Iowa State FAQ and the Missouri article give 40 to 50 degrees Fahrenheit. The Iowa State FAQ also says the tubers should not freeze. The Iowa State guide to tender perennials says a garage can get below freezing in extreme weather, which is too cold for survival.

Should the packing material be dry or damp?

The sources differ on the wording. Iowa State describes dry peat moss, vermiculite or sawdust, Missouri describes the same materials as slightly moist, and NC State describes a dry medium. The Missouri article adds that it is better to err on the dry side, so a dry packing is the safer reading of the sources.

When should begonia tubers be started indoors again?

The NC State profile says to start them indoors in late winter, about 2.5 to 3 months before all threats of frost are over. The profile gives no calendar date, so the last frost date for the garden is needed to turn that window into a day.

Sources

• https://yardandgarden.extension.iastate.edu/faq/how-do-i-overwinter-tuberous-begonias (opened 2026-10-23)
• https://ipm.missouri.edu/meg/2008/11/Storage-of-Tender-Bulbs/ (opened 2026-10-23)
• https://plants.ces.ncsu.edu/plants/begonia-tuberous-types/ (opened 2026-10-23)
• https://yardandgarden.extension.iastate.edu/how-to/how-overwinter-tender-perennials (opened 2026-10-23)