Gardening Roulette

Each fall, gardeners engage in an interesting game called “gardening roulette.” The rules vary but the object of the game is to see how long to leave tender plants in the garden without them freezing. Guessing how long the weather will hold is frustrating . Saving plants from the certain fate of a killing frost is a laudable objective but determining when to do it is a bit more risky. Lifting dahlia and begonia tubers is an annual task. They are tender and will not survive our winters. These must be protected from hard frosts or the plants will be destroyed. There is really no good excuse for digging through the snow to rescue these bulbs. Enjoy their beauty but take care of them before they freeze. None of them require frost before digging. Digging them during relatively warm fall weather is preferable to digging them in cold and snow. After digging, the tubers must be stored in a cool, dark place until spring. Use any durable container such as plastic boxes, nursery tubs, garbage cans or even boxes with plastic bags for liners. Although the specific criteria might vary slightly, these guidelines will help store the tubers until next spring. All must be stored so that they do not freeze but they must stay cool enough that they will not start to grow before spring. Dahlias are best stored in clumps and divided in the spring just before planting. Each division must have at least one bud. The buds are most easily noticed in the spring, just as the tubers start to sprout. Dahlias shrivel badly if the humidity gets too low, but will rot rapidly if it is too high. Store them by burying them in sand, peat moss, vermiculite, or sawdust. Put a layer of the mulch in the container and then a layer of the tubers. Add additional mulch and layers of tubers until the container is full. Place a glass of water in the mulch and let it stay there to evaporate and increase the humidity. Check the tubers at least monthly. If the tubers are starting to shrivel, sprinkle a few drops of water over the top of the container before closing it. If excess moisture or mold is present, leave the tops open for the tubers to dry out. Store tuberous begonias the same way. Divide them very carefully, because each division requires a bud to grow. Caladiums and calla lilies are becoming more common as landscape plants. Dig and treat these the same way. Next week we will cover cannas, gladiolus and other summer “bulbs.” Larry A. Sagers Regional Horticulturist Utah State University Extension Thanksgiving Point Office