Bulbs to Dig Up Before Winter (and Which to Leave in the Ground)
As temperatures drop and summer flowers fade, one question can make fall garden cleanup confusing: which bulbs need to come indoors?
Digging up every bulb creates unnecessary work. Leaving tender plants in freezing soil, however, can mean losing flowers you hoped to grow again next year.
The answer depends on the plant, your winter temperatures, and your soil’s drainage.
In regions with freezing winters, dahlias, cannas, tender gladioli, tuberous begonias, caladiums, tender elephant ears, and colored calla lilies often need lifting or indoor protection. Locally hardy daffodils, tulips, crocuses, and true lilies generally stay in the ground.
Here’s how to decide what needs attention before winter arrives.
How to Tell Whether Your Bulbs Can Survive Winter
Gardeners often use the word “bulbs” to include tubers, corms, and rhizomes. Although these underground structures differ, they all store energy that supports future growth.
Before lifting anything, check the plant’s identity and hardiness.
A common name is not always enough. Some gladioli are much hardier than others, and the winter needs of a white arum lily differ from those of many colorful calla hybrids.
Next, consider your planting conditions. A sheltered garden with freely draining soil offers different conditions from an exposed bed that stays wet throughout winter.
Cold tolerance and drainage matter more than whether the plant flowers in spring or summer. Many summer-flowering true lilies are hardy, while tropical foliage plants may need protection well before severe frost arrives.
7 Bulbs and Tubers to Dig Up Before Winter in Cold Climates
1. Dahlias
Dahlias grow from fleshy tuberous roots that can be damaged by freezing conditions and persistent winter wet.
In cold climates, lift them after frost blackens the foliage, before the ground freezes. Dig around the outside of the plant and raise the clump carefully, avoiding damage where the tubers join the crown.
Let surface moisture dry before storing the clump somewhere cool and frost-free. Avoid allowing the tubers to become completely dehydrated.
Can dahlias stay in the ground? Sometimes. In mild gardens with good drainage, they may overwinter beneath a protective mulch. The Royal Horticultural Society recommends approximately 6 inches of mulch when leaving them outdoors in suitable conditions.
Where winters are severe or soil remains waterlogged, lifting is more dependable.
2. Cannas
Cannas bring tropical-looking foliage and bold flowers to summer borders, but their rhizomes need protection where winter temperatures would kill them.
After frost kills the foliage, cut the stems back to approximately 4–6 inches. Lift the rhizomes carefully, keeping a little soil around them, and allow them to dry briefly.
Store them in suitable packing material in a cool, frost-free location.
Iowa State Extension recommends a storage temperature of approximately 40–50°F (4–10°C) for cannas.
Check the storage area with a thermometer. A garage that freezes during cold spells does not provide reliable protection.
3. Tender Gladioli
The large-flowered gladioli commonly grown for summer bouquets are often lifted in cold regions.
Their underground corms should be allowed to mature before lifting, then dried thoroughly before winter storage. Label each variety while you can still identify it.
However, do not assume every gladiolus needs the same treatment.
Some species, including Byzantine gladiolus, are hardier than tender summer hybrids and may remain outdoors where locally suitable.
Check the variety’s hardiness before adding it to your lifting list.
4. Tuberous Begonias
The large-flowered tuberous begonias used in shady containers and hanging baskets need frost-free winter protection.
As growth slows and the plants become dormant, reduce watering and allow the foliage to die back. Lift the tubers, let them dry, and remove loose soil and dead stems.
Store them in a dry, frost-free location and inspect them periodically.
This method applies specifically to tuberous begonias. Wax begonias and other fibrous-rooted types do not form the same storage tubers and need a different approach.
5. Caladiums
Caladiums need earlier attention than many other plants on this list because they are especially sensitive to cold.
Bring them under protection before frost. After lifting, allow the tubers to cure and remove dried foliage before storage.
Their storage temperature is particularly important.
Iowa State Extension recommends approximately 60–65°F (16–18°C). A chilly room suitable for cannas may be too cold for caladiums.
Keep their storage box separate and clearly labeled so they receive the warmer conditions they need.
6. Tender Elephant Ears
Elephant ears include plants from several genera, such as Colocasia, Alocasia, and Xanthosoma. Their hardiness and dormancy habits vary.
Where your plant cannot survive outdoors, you may be able to lift its underground storage structure or bring a suitable potted specimen indoors.
For dormant storage of commonly grown tender elephant ears, Iowa State Extension recommends curing the lifted material and storing it at approximately 55–60°F (13–16°C).
Identify the plant before deciding how to overwinter it. A method suitable for one elephant ear may not suit another.
7. Tender Calla Lilies
Many colorful calla lilies need frost-free winter protection in cold climates.
As growth finishes, reduce watering and prepare the plants for dormancy. Lift rhizomes from garden beds where necessary, or move containers into suitable protection.
The familiar white arum lily, Zantedeschia aethiopica, is hardier than many colored calla hybrids and may remain outdoors in suitable mild gardens.
Check the species and cultivar rather than relying on the name “calla lily.”
Bulbs You Can Usually Leave in the Ground
Bulbs that are hardy in your area generally do not need annual fall lifting. Leave healthy, established plants undisturbed unless you need to divide them, move them, or correct unsuitable growing conditions.
Daffodils
Most familiar garden daffodils are hardy, long-lived plants that return for years.
Leave them in well-drained soil over winter. Digging and dividing may eventually help overcrowded clumps, but that is different from lifting for cold protection.
Check the variety when growing less hardy narcissus types rather than assuming every plant in the group tolerates the same temperatures.
Tulips
Garden tulips generally stay planted through winter where they are locally hardy. Autumn is their normal planting season.
Advice to lift tulips usually refers to summer lifting after the foliage yellows, followed by replanting in fall. This can provide a dry summer rest or help manage seasonal displays.
It does not mean tulips normally need indoor winter storage.
Some varieties return more reliably than others. Winter survival alone does not guarantee equally strong flowering every year.
Crocuses
Common hardy spring crocuses can remain outdoors through winter.
Choose types suited to your climate and avoid planting them where water collects. Healthy, established corms do not need to be dug up every autumn.
Hardy True Lilies
Many true lilies, including locally suitable Asiatic hybrids, can remain in the ground over winter.
Check the particular variety’s hardiness and provide well-drained soil.
True lilies belong to the genus Lilium. Their winter care differs from that of plants commonly called canna lilies or calla lilies.
When Should You Dig Up Tender Bulbs?
Use the plant’s condition and your weather forecast rather than a fixed calendar date.
October may be the right time in one garden, while another needs action in September or can wait until November.
Many tender bulbs can be lifted after their foliage dies back or is damaged by an initial frost, provided the underground structures have not frozen. More cold-sensitive plants, including caladiums, should come under protection earlier.
Prepare storage containers and labels in advance so a sudden temperature drop does not catch you unprepared.
How to Store Bulbs Over Winter
Lift Without Damaging the Plant
Loosen the soil around the clump before lifting from underneath. Avoid pulling hard on the stems or driving a fork through the underground structures.
Keep labels attached throughout the process.
Follow the Correct Curing Method
Curing allows surface moisture to dry before storage. The time required varies by plant.
Remove loose soil and follow the instructions for the particular bulb, corm, rhizome, or tuber. Do not pack freshly lifted, wet material straight into a closed container.
Use Suitable Containers and Packing
Choose containers that allow ventilation. Suitable packing material helps separate and protect the stored plants.
Avoid sealed plastic bags that trap moisture.
Match the Temperature to the Plant
There is no single ideal storage temperature for every tender bulb.
Cannas, caladiums, and elephant ears have different requirements. Check the temperature where the plants will actually sit, including during the coldest weather.
Inspect Throughout Winter
Check stored material periodically for rot, excessive shriveling, condensation, or premature growth.
Remove rotting material promptly and adjust conditions to suit the species. Do not automatically water every bulb or tuber in storage.
What About Bulbs in Containers?
Potted plants need their own winter plan.
For some tender plants, moving the entire container into suitable protection can be easier than lifting its contents. Follow the plant’s dormancy and watering requirements rather than treating every pot alike.
Outdoor tulip containers also need attention to drainage. If the compost becomes sodden, move the pot temporarily into shelter from excessive rain.
Hardy spring bulbs should not automatically be brought into a heated living room when temperatures fall. Many need a cold period as part of their normal growth cycle.
Frequently Asked Questions
Do all flower bulbs need to be dug up before winter?
No. Plants that are hardy in your location normally remain outdoors. Lift or protect those that cannot tolerate your winter conditions.
Can mulch protect dahlias through winter?
Mulch can help in mild gardens with good drainage. It is not dependable protection against severe cold or persistently wet soil.
Should I dig up tulips in October?
Usually not for winter protection. October is commonly a planting period. Tulips lifted for summer storage are replanted in autumn.
Can I store all tender bulbs together?
Only when their storage requirements overlap. Caladiums need warmer storage than cannas, so the same location may not suit both.
Is an unheated garage suitable for storing bulbs?
It can be if temperatures remain within the range required by the plants. Use a thermometer because garages may freeze or become too warm.
When can stored bulbs go back outside?
Plant tender bulbs outdoors after frost risk has passed and the soil has warmed sufficiently for the species. Some can be started indoors earlier.
