Growing Green

By Robin Trott, Extension Educator

Fall is definitely my favorite time of year. The brisk nights, cool clean air, crunch of leaves and final garden chores of the season warm my heart and ready me for the long winter’s hibernation. Our dahlias have been lovely and productive this year, and in a few weeks’ time will be no more. Then comes the task of digging and storing the tender tubers for the winter.

A tender bulb is a plant with a fleshy storage structure (bulb, tuber, corm, rhizome) that cannot survive the cold, Minnesota winter. These include: anemone, tuberous begonia, caladium, calla lilies, canna, dahlias, gladiola, tuberose and many others. Special care, which includes digging and storing in a warmer area for the winter, is required to keep these plants from year to year. Most should be dug after the foliage has dried up or been killed by frost.

• Dig Carefully. Loosen the soil gently with a garden fork and lift roots cautiously to avoid damage or breakage.

• Cleaning. Some roots, such as Dahlias, should be washed off with a hose and left to dry. Others, such as gladiolas, are better left unwashed and allowed to dry. After drying, the soil may be gently removed.

• Curing. Place bulbs in a dry, well-ventilated area between 60-70°. Dahlias, Canna, Calla and Caladium take about 1-3 days to cure.  Gladiolas take about three weeks.

• Pest Management. Before storing, check your roots for disease and insects.  If necessary, dust with an insecticide/fungicide mixture labeled for use on the specific plant.

• Storing. Make sure to label all stored bulbs. Smaller structures, such as gladiolas, can be stored in a paper bag. Larger roots such as dahlias and canna, (you can write the cultivar directly on each root with a permanent marker), pack roots in vermiculite or peat moss and store in a perforated plastic bag, onion bag or burlap sack. (I get coffee sacks from Dunn Brothers Coffee.)

Periodically check stored bulbs, tubers and roots during the winter months. Remove any damaged or rotting material. Remember that these structures are dormant, living plants and may need attention and care through the winter.

For more information on digging and storing tender bulbs, visit www.extension.umn.edu.

Until next time, happy gardening!

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“A few days ago, I walked along the edge of the lake and was treated to the crunch and rustle of leaves with each step I made. The acoustics of this season are different and all sounds, no matter how hushed, are as crisp as autumn air.” ~Eric Sloane