The question comes up every year. Shall I dig my dahlia tubers and store them for the winter, or is it OK to leave them in the ground?
Dahlias are native to Mexico and Central America, so that tells us immediately that they won't grow and bloom all winter in the Rogue Valley. So now there are some choices to be made.
Unfortunately, those choices include some gambling with the weather. Left in the ground, most dahlia losses in our area are not from freezing, but from being too wet and rotting. Because dahlias like rich, well drained soil, they are likely to rot if we have a particularly wet winter or if you have quite a lot of water-holding clay in the dahlia bed.
Having lost mine to rot, I always dig them now.
But there is another choice, and that is to grow them as if they were annuals. This means leaving them in the ground, and buying new tubers each year. Some people like to do that for the experience of trying new types and colors. And it's less work.
Thanks to breeders, dahlias are now available in every color but blue, and in a wide variety of shapes and styles. They range from 2-inch pompoms to dinner-plate size, from formal to cactus-type with their rolled, curved petals, from single to water-lily style, and many in between. As for height, dahlias are available from one to eight feet tall.
If you want to save some of your lovely specimens for next year, here's how to keep them over the winter. After the last flowers have faded, and two or three weeks after a killing frost, take your spading fork and head for the dahlia bed.
With a sharp knife or pruners, cut off the stalk to 3 or 4 inches. At this point, attach a plant label of some kind so you know who's who. Carefully dig the tuber clump and gently shake off as much dirt as you can. Let the clump dry, out of the sun — on newspaper on your garage or shed floor is ideal — for a couple of days.
Use a permanent marker to label the individual tubers, and pack the intact clump in a container of damp (not wet) sand. Some people like to separate the clumps before packing, but I find that opens the tuber to mildew. Besides, it's easier to separate the clumps into individual tubers in the spring, when they are beginning to sprout.
Check the tubers a couple of times during the winter to be sure they're not mildewing and to ensure tubers aren't shriveling because the packing material is too dry.
As you plan and dream about next year's garden during the winter season, why not include a few new dahlias you've never grown before? Try a collarette, or a peony-flowered, or a single-petaled, or a white one with red edges, or ...
Coming up: Rhianna Simes, Citizen Fire Academy coordinator, will teach a class on creating a safe and beautiful landscape with fire-resistant plants. The class will be from 7 to 9 p.m. on Wednesday, Oct. 23, at the Southern Oregon Research and Extension Center, 569 Hanley Road, Central Point. The cost is $5. Call 541-776-7371 to register.
Gardeners with all levels of experience can enjoy a full day of gardening classes at the Jackson County Master Gardeners 15th annual Winter Dreams, Summer Gardens symposium on Nov. 2, at the RCC/SOU Higher Education Center in Medford. Attendees can choose four classes from the 40 offered on a variety of gardening topics. Cost is $40 for the day, including lunch. Call 541-776-7371 for a registration packet.
Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. Email her at firstname.lastname@example.org.