This past week we finally received our first killing frost of the season. It’s time to perform the fun task of digging up the roots we want to save and store over the winter. These would be the tender roots of the cannas, dahlias, gladioli, caladiums, callas, begonias and ismenes. If left in the ground in our region, they will surely rot due to the extreme winter temperatures. All of these plants need a killing frost before digging to stop the growing process, except for the ismenes.
In this article, we will refer to the bulbs as roots, as they are not all true bulbs. The cannas and callas are rhizomes, the dahlias and begonias are tubers, the gladioli and caladiums are corms, and the ismenes are bulbs.
When digging out any of these roots, always use a fork or spade to lift them from the ground. Place the digging utensil one foot out from the stem of the plant and go down at least 8 inches to avoid injuring any of the root systems. Gently move the tool back and forth until you can lift out the root ball and brush away any loose soil.
After the roots are lifted, wash them off with water to remove the soil. Do not give them a hard spray as this may damage some of the tender roots like that of the begonias and dahlias by removing their tender skins. Once the roots are cleaned of soil, cut the vegetative portion of the plant back to 6 inches from the roots and leave them out in a warm, dry area for five to seven days to sufficiently dry out.
Ismenes are the one type of bulb that needs to be dug up before the first frost. These bulbs are also known as Peruvian daffodils and bloom in June. The bulbs resemble that of the amaryllis. Their fleshy roots need to be stored in a dry and dark location that is around 60 degrees for best results in an open-air container.
Cannas and callas should have all damaged parts of the root systems removed with a very sharp knife to make sure all cuts are clean and free of disease. Pack them in a box or bag with peat moss or perlite around them so the roots are not touching each other. Store in a cool, dark and dry area at around 50 degrees.
Dahlias and begonias have a more tender root and need a little extra care when lifting. Do not damage or injure the roots when removing the soil. If a tuber is broken in half, it will not grow and needs to be discarded. Most tubers will have growth “eyes” on the upper end. Save and store these tubers over the winter. Rotten, diseased or damaged roots should be discarded. Store in a box or bag surrounded by peat moss or perlite in the same conditions as cannas and callas.
Gladioli and caladiums are a bit easier to dig as they have a smaller root system and have corms, which are easier to handle. The original corm that was planted in the spring will have shriveled up and the new corm will have formed directly above it. After five to seven days of drying them in the air, you will be able to snap off the old corm from the bottom the healthy one and discard that portion. Store in an onion sack or nylon stocking and hang them from the ceiling. This allows for good air circulation, which keeps mold and fungus from forming. They also prefer a cooler temperature of about 40 degrees for storage.
All types of roots should be shaken or dusted with a insecticide/fungicide mixture to prevent any bugs and disease. Check on the roots once a month during their storage period to make sure none are starting to rot, discolor or dry out. If some have discolored or begun to rot, remove them as soon as possible so they do not affect the others. Any roots that look to be drying out and becoming shriveled, give them a light mist from a spray bottle to add a little moisture. Never spray into a bag and then seal it up as this will cause too wet of a storage environment for your roots.
Typically one can expect to lose about 10 percent of the roots in the winter storage process, but it is well worth the effort. With the cost of some of the varieties out on the market, some of them are best saved from year to year with a little extra effort.
These bulbs can be planted directly into the garden in the springtime after the threat of frost has left for another year of beautiful blooms. Caladiums would be the one root to start earlier in the spring inside before planting as they need a lot of heat and humidity to start growing. Once they have begun to grow, transplant them into the yard after the soils have warmed.
As much fun as the digging process can be, especially when the winds are howling at forty miles per hour and the temperature is hovering around thirty-five degrees, it is very rewarding in the spring when you can start these roots all over again. Once they all begin to bloom in the garden, we forget the effort it took to get them to this place again. In fact, as we are enjoying them on a nice warm 80-degree day, we quickly forget about the actual storage process which keep these wonderful plant species from year to year. In some ways, they are like our friends, some take a lot of special care and attention that may seem to drain us at times, but when they truly shine for you, it makes it all worthwhile.