How can I keep my dahlia roots for next year? Frost killed the tops last week. I spent good money on the roots and I’m not willing to let them become expensive compost.
I’m with you. It takes just a few minutes to dig and store dahlia tubers, so why not keep them for a repeat performance next summer? Dahlias survive the winter outdoors in Zone 9 and warmer; everywhere else, you can dig up the tuberous roots and overwinter them indoors. The same technique works for cannas and other tender summer bulbs.
After frost, cut the stems to stubs. The sweet-potato-like dahlia tubers extend outward from the stem about 6 inches, so be careful not to slice into them while digging. Shake the soil off the roots and let them dry in the garage for a few days. If you have more than one variety, write their names on the tubers with a felt-tip marker.
Some gardeners divide their dahlias at this point, leaving one growth bud or “eye” per division and dusting the cut surfaces with garden sulfur as a fungicide. I prefer to store dahlia and canna clumps intact, waiting until spring to divide them, because I’ve had better success that way.
Pack the roots in paper bags or cardboard boxes with dry sphagnum peat moss, sawdust, or vermiculite surrounding them. Store them at a steady temperature between 35°F and 45°F. Back in the days of unheated, damp basements and root cellars, it was easier to store tender roots without their shriveling. Nowadays drier basements prevail, and it’s wise to check on the stored roots monthly. If they start to shrivel, lightly moisten the sawdust or peat. —Doug Hall
I need to store my potato harvest and I keep reading 45 degrees and dry. My basement has a dirt floor, thus making it not really what I would call dry. Underneath the front porch is a closed-off space but I’m afraid the potatoes will freeze there. Any other ideas?
The University of Idaho Potato Storage Research Facility recommends a cool temperature of 45°F and 95 percent relative humidity for potato storage. Unless your basement is so humid that condensation is running down the walls, it is probably your best choice. Potatoes can be kept at temperatures between 35°F and 60°F—but at the colder end of that range, starch in the tubers will convert to sugar, resulting in dark, discolored flesh when the potatoes are cooked. At the higher end of the range, the quality of the stored potatoes diminishes more rapidly and the tubers will be quicker to sprout.
When harvesting and handling your potato crop, protect them from bruises and cuts. It’s okay to give potatoes a quick rinse to remove soil, but don’t scrub them, because any scrapes or breaks in the skin—even microscopic ones—can allow disease pathogens to enter, leading to decay. Allow the potatoes to “cure” for a week after harvest at about 60 degrees before moving them to the cooler storage temperature; this gives the skins a chance to toughen up, helping them to resist shriveling and decay.
Finally, store the tubers in single layers on lath shelves or mesh nursery flats so air can circulate around them. The storage area should be completely dark to avoid the formation of solanine, a toxic alkaloid produced when potatoes turn green. Check on your potatoes regularly and remove any that are going soft. —Doug Hall