I had another highly successful year of growing dahlias. Not only did my direct planting experiment work well, but I grew some unexpectedly robust dahlia plants from seed. The only trouble with that was that they didn’t bloom until a couple of weeks before killing cold weather. This inspired me to dig them up and try to save them for next year, something I haven’t done with dahlia tubers before.
Fortunately, Swan Island Dahlias sends a wonderful little growing guide with their tubers. The first step is knowing when to dig. In summary:
- wait until the plants have died back, indicated by turning black and brown
- cut the stalks off at about 6 inches
- dig gently to avoid breaking them
- wash them (which I didn’t get to), then let them dry in a protected place for about a day
For winter storage, they recommend between 40 – 50°F. Our basement is too warm, even the cooler pantry room, which hovers around 60°F. The greenhouse is inconsistent, getting quite warm on sunny winter days. Plus, it is a high humidity location with the pond and waterfall. The garage seemed the best option, but it would take some work. Thus, I engaged in a quick garage insulating make-over, which I wrote about for D&B Supply.
- a storage medium, like slightly dampened peat moss, sand, or saw dust
- cardboard boxes or ventilated crates
- lining of newspaper or something similar
With the following procedure:
- line the box with around 10 sheets of paper
- put an initial layer of packing medium over the paper
- add a layer of tubers
- add more storage medium
- and so on until the box is full
- check the tubers throughout the storage time
Here’s what it looked like when I did it (click on any photo to enlarge):
The growing guide also gives some very nice instructions (with a simple illustration) for dividing the tubers, which I plan to do, since most of my tubers are huge! This, of course, depending on how well I monitor and regulate the temperature for their storage. We are expecting some sub-zero lows pretty soon. I might have to bring them into the laundry room for a few nights until I get the final insulating and heating options for the garage worked out. All the while, I will dream of dahlias blooming next year.
Edit 4.14.2017: My husband purchased a temperature regulated heater to hang near the dahlias, away from the walls. The heater was designed to switch on if the surrounding temperature was below a certain point. This point could be set on the heater.