Open Grow Guide

Lifting and storing tender bulbs

By Open Grow Guide Updated

Outside USDA zones 8b through 11, caladium tubers need to be dug and stored each year before frost. Dahlia tuberous roots can be injured once temperatures drop below 25 °F (-4 °C). Elephant ears can survive a light frost, but not a hard freeze. When frost threatens, it's time to prepare tuberous begonias for winter storage. After frost kills the foliage, dig up canna rhizomes in fall. Caladiums should be harvested and stored before the first fall frost. This guide walks through digging, drying, and storing these tender bulbs so you can plant them again next spring.

When: Fall (Oct–Nov)

When to do it

Timing for lifting tender bulbs follows the first frost of fall, not a date on the calendar. A light frost that kills the foliage is the first sign it's time to dig. Wrap up digging before a hard freeze sets in and threatens the roots. A light frost will not harm elephant ears, but a hard freeze will. Temperatures below 25 °F (-4 °C) can injure dahlia tuberous roots. Gladiolus corms left in place longer have more time to mature. Gladiolus corms come out once their tops die back, but before a hard freeze. Gardeners outside USDA zones 8b through 11 need to lift caladium tubers before frost arrives each fall.

What you need

Gathering the right supplies before frost arrives makes lifting and storing tender bulbs faster. Dahlia stems are cut to 6 in (15 cm) and canna stems to 2-3 in (5-8 cm). For drying, set aside a light, airy, warm spot, since gladiolus corms dry best spread out there. Keep dry peat moss, vermiculite, dry sand, or sawdust on hand as packing material for winter storage. Paper bags, cardboard boxes, or mesh bags work well for storing gladiolus corms over winter. An insecticide-fungicide dust is useful for treating caladium tubers before storage. A spray bottle lets you mist bulbs with a little water if they start to shrivel. Reserve space in a cool, frost-free area, like an unheated basement or attached garage, for the whole winter.

Step by step

  1. Step 1

    Watch for the first frost warning

    It signals time to prepare begonias for winter storage.

  2. Step 2

    Stop watering caladiums as fall leaves start to yellow

    Withdraw water gradually, not all at once.

  3. Step 3

    Dig tender bulbs after a light frost kills the tops

    Finish before a hard freeze, which can kill the roots.

  4. Step 4

    Check elephant ears before you decide to dig

    They survive light frost but not a hard freeze.

  5. Step 5

    Dig caladiums every year if you garden outside USDA zones 8b through 11

    Lift them before frost in these zones.

  6. Step 6

    Dig caladiums even where they can overwinter outdoors

    They perform better lifted away from wet soil.

  7. Step 7

    Protect dahlia roots from temperatures below 25 °F (-4 °C)

    Dig before a cold spell reaches this point.

  8. Step 8

    Cut dahlia stems to 6 in (15 cm) after a killing frost

    Wait until frost blackens the foliage first.

  9. Step 9

    Wait four to eight days for the eyes to develop

    Then dig, dry, and store the tubers.

  10. Step 10

    Dig canna rhizomes in fall after frost kills the foliage

    Wait for this dieback first.

  11. Step 11

    Cut canna stems to 2-3 in (5-8 cm)

    Trim this short before storage.

  12. Step 12

    Remove potted begonias from their pots before hard frost

    Do this while plants are still in containers.

  13. Step 13

    Dig begonia tubers when foliage yellows or light frost hits

    Either sign means it's time to lift.

  14. Step 14

    Cut begonia stems down to 5 in (13 cm)

    Trim them after you dig the tubers.

  15. Step 15

    Dig gladiolus corms any time before the ground freezes

    This gives you a wide window.

  16. Step 16

    Leave gladiolus corms in the ground as long as possible

    Extra time lets the corms mature.

  17. Step 17

    Dig gladiolus corms after the tops die back but before a hard freeze

    This timing avoids freeze damage to the corms.

  18. Step 18

    Harvest and store caladiums before the first fall frost

    Don't wait for frost to reach them.

  19. Step 19

    Dig elephant's ear before frost arrives

    Let it dry, then store it.

  20. Step 20

    Dig up Colocasia tubers after the first frost

    Lift them from the ground at this point.

  21. Step 21

    Leave soil on tender bulb roots instead of washing it off

    Washing causes rot, so skip rinsing.

  22. Step 22

    Dig dahlia tubers and dry them without washing

    Keep soil on the roots instead of rinsing.

  23. Step 23

    Spread gladiolus corms outside in a light, airy, warm spot

    This open warm spot dries the corms.

  24. Step 24

    Remove the old withered corm after two to three weeks of drying

    Then discard this old corm completely.

  25. Step 25

    Clean soil from caladium tubers and dry them in semi-shade

    Let them dry for about 10 days.

  26. Step 26

    Air-dry caladium and begonia bulbs for one to two days

    Do this right after digging them up.

  27. Step 27

    Dry canna rhizomes for several days before storage

    Then move them to a cool area.

  28. Step 28

    Dry begonia tubers indoors at room temperature

    Do this after you cut the stems back.

  29. Step 29

    Cure begonia tubers for several weeks in a dry, cool spot

    A basement or garage works well.

  30. Step 30

    Shake soil off the tubers once curing is done

    Remove leftover stalks and roots, since they can rot and spread to the tuber.

  31. Step 31

    Cut other tropical bulbs to 4-6 in (10-15 cm) of foliage

    Lay them in a warm spot to dry.

  32. Step 32

    Avoid propagating begonias by cutting the tubers apart

    Cutting can introduce disease and cause rot.

  33. Step 33

    Dust caladium tubers with an insecticide-fungicide before storage

    Apply it as the last step.

  34. Step 34

    Store dahlia tubers in vermiculite or dry sand at 35-45 °F (2-7 °C)

    Keep them in this cool range all winter.

  35. Step 35

    Alternatively, store dahlia tubers in dry peat moss or sand at 55-65 °F (13-18 °C)

    This is another storage option for winter.

  36. Step 36

    Store gladiolus corms over winter at 35-45 °F (2-7 °C)

    Keep them in a well-ventilated spot.

  37. Step 37

    Alternatively, store gladiolus corms in paper bags or mesh bags at 40-50 °F (4-10 °C)

    Keep them in a cool spot through winter.

  38. Step 38

    Store caladium tubers in dry peat moss or vermiculite at 50-60 °F (10-16 °C)

    Keep them in this range all winter.

  39. Step 39

    Store begonia tubers after frost in dry peat moss at 35-41 °F (2-5 °C)

    Keep them in this cool range all winter.

  40. Step 40

    Alternatively, store begonia tubers in a dark, dry, cool spot just above freezing

    Pack them in dry peat, sawdust, or sand.

  41. Step 41

    Store elephant's ear tubers in a dry area at 70-75 °F (21-24 °C)

    Keep them warm and dry all winter.

  42. Step 42

    In colder areas, store calla lily in pots indoors at 50-60 °F (10-16 °C)

    Keep the potted plant at this range all winter.

  43. Step 43

    Choose a cool, frost-free spot, such as an attached garage or unheated basement

    Aim for 45 °F to 55 °F (7-13 °C) in that space.

  44. Step 44

    Keep stored bulbs dry enough that they don't rot

    Keep them moist enough that they don't shrivel.

  45. Step 45

    Check stored bulbs periodically through the winter

    Discard any that feel soft, withered, or rotting.

  46. Step 46

    Spray stored bulbs with a little water if they shrivel too much

    A light spray is usually enough.

  47. Step 47

    Pot up tubers 4-6 weeks before your last frost date in spring

    Start them indoors in a warm, sunny spot.

  48. Step 48

    Divide canna rhizomes every few years in spring

    Spring is the right time for this.

  49. Step 49

    Grow elephant's ear in a container instead of digging it up

    Move the container indoors for winter.

Mistakes to avoid

Washing them causes rot, so leave some soil on the roots instead. Waiting too long to dig is another mistake, since a hard freeze can kill roots that a light frost leaves unharmed. For dahlias, that risk starts once temperatures drop below 25 °F (-4 °C). Propagating tuberous begonias by cutting the tubers apart is also a mistake. Cutting can introduce disease and cause the tubers to rot. Skipping the drying and curing stage causes problems too. Caladium and begonia bulbs need one to two days of air-drying. Begonia tubers also need several weeks of curing in a cool, dry spot before storage. Leaving old stalks and roots on a cured begonia tuber is a mistake as well. Any leftover material can rot and spread to the tuber. Bulbs kept too wet in storage rot, and bulbs kept too dry shrivel. Keep them dry enough not to rot, but moist enough not to desiccate. Skipping periodic checks during winter is a mistake, since soft, withered, or rotting bulbs need to be found and discarded.

How this page was made

  • Written with AI assistance from the sources listed on this page. AI is never the source of a fact.

How we work