Storing Dahlias, Cannas and Begonias

Q: How do I store tender bulbs like dahlias, cannas and begonias for next year?

A:  In a dry climate like Colorado, storing tender bulbs like cannas, dahlias, gladiolus and begonias requires some additional care due to the low humidity. The goal is to prevent the bulbs from drying out too much during winter storage. Here's how to store them successfully:

Dig Up the Bulbs.  After the first frost, dig up the bulbs carefully.   Gently remove as much soil as possible and leave about 2-3 inches of stem attached.  

Clean and Cure the Bulbs. Let the bulbs cure in a shaded, dry, frost free area for a day or two.  This toughens the “skin” of the bulbs and helps prevent rotting during storage. 

Protect Against Excessive Dryness.  Because the air is so dry, bulbs can shrivel and lose moisture quickly. To combat this:

• Pack with moisture-retaining material: Use slightly damp peat moss, sawdust, or vermiculite to surround the bulbs.

• Wrap in newspaper or paper bags: This helps trap some moisture around the bulbs without making them too wet.

Storage Location.  Store in a cool (40-50°F ), dark location such as an unheated garage, basement, or frost free shed.

Monitor and Adjust.  Check regularly: Since Colorado’s dry air can pull moisture from the bulbs, check monthly for signs of shriveling or mold.  If bulbs seem too dry or shriveled, lightly mist the packing material again.  If any bulbs are rotting, remove them to keep the rot from spreading to other bulbs.