Master Gardener Sue Morris: Make a plan for care of tender bulbs to be dug up this fall
How to dig up and store the bulbs you planted last spring.
This is the time of year to start thinking about what we need to do to take care of the bulbs we planted this spring for summer blooms. These are tender bulbs which will not make it through a Minnesota winter. Included in this group are amaryllis, canna, glads, begonia, dahlia, elephant ears, caladium and even voodoo lily.
These should be dug in the fall after foliage turns yellow, dries up or is killed by frost. Curing should be done in a room or area away from direct sunlight or drying winds, and the temperatures for curing should be around 60 to 70 degrees.
Glads can be dug 6 to 8 weeks after bloom. By then they have grown new corms for use next year.
The method I use for glads is to cut the stems back to about three or four inches, lay them in the dark basement for at least three weeks and then clean the corms up by breaking off the old corm on the bottom and break off what is left of the stalk.
Then I store them in cardboard boxes — peach crates work well — right side up and not touching.
Then in early spring when they start to sprout, the sprouts will grow straight up. If you store them in a mesh bag, the sprouts will become all twisted and more difficult to plant.
In the spring before planting, the corms should be dusted with an all-purpose bulb dust to prevent thrips wrecking your flower buds when they appear.
Dahlias need to be hit by a killing frost before you think about digging them.
Two or three days later, cut the stalks down to about six inches and then leave them in the ground for a couple more days.
Then it is safe to dig them — loosen with a garden fork several inches away from the base of the plant as they will have formed many new fingers in their clump. The clump then can be washed off with a garden hose.
Let the clump dry in a dark place for a couple days and then store with your favorite method.
When I grew dahlias, I would store them in pails of sand.
You can also store in boxes of vermiculite but will need to check them during the winter and probably mist them so they don’t dry up.
Some have good luck separating them, wrapping them in plastic wrap and storing in an old refrigerator.
Avoid cutting or breaking the fleshy structure on all bulbs as diseases can easily contaminate plants through cuts and bruises causing rot and/or death.
Store bulbs in cool, dry conditions and an average of 40 degrees. Peruvian daffodil and tuberose need to be stored at 60 to 65 degrees.
Don’t store damaged or too small bulbs as the damaged ones may rot and small bulbs may dry up. Check stored bulbs periodically and remove any that are damaged or rotting.
Fall planted bulbs including tulip, daffodil, lily, hyacinth, crocus, iris, snowdrops, allium, grape hyacinth should be left in the ground as they require a period of cold temperature to break dormancy to flower.
Every three to four years, they should be dug up in the fall, divided and replanted. Don’t dig them until the foliage has yellowed and withered.