Digging up Bulbs for Winter Storage in Alberta
Freshly dug Gladiolus laid out to dry
I recently made a timelapse video of cleaning up my gladiolus, dahlias, and calla lily bulbs and corms to store for the winter. Since it's a timelapse, it's not an incredibly informative video, but I have a caption in the video that mentioned not doing your dahlias the way I did.
So here’s a little explanation about how and why I dig up and store some of my flower bulbs for the winter.
Gladiolus
Gladiolus, or Sword Lilies, are a perennial flower, but they’re only hardy to USDA growing zone 5. Which usually means one zone higher according to the Canadian growing zone system, so 6.
Where I live, in Lacombe, Alberta, we are currently classified as Zone 3b on the Canadian system.
On top of that, my gladioli are usually grown in a raised bed in the front yard. So they’re more protected by being on the south side of the house, but they’re in a raised bed, so more vulnerable to freezing solid than bulbs in the ground are. So, every fall, I dig them out, brush the dirt off, and store them for winter.
Full transparency, this is only my second winter storing them, and I’m trying something different this year.
Last year we dug them out, brushed off the soil, chopped the tops off, threw them in a mesh bag leftover from onions, and hung them in the garage. This worked fine. I think maybe one or two started to rot over the winter. I had to relocate them later in winter because the heated floor got turned on, and the garage got a little too warm, so they sprouted too early. They spent the rest of the winter in our cold room.
This year, I dug them on October 15, after we’d had frost a couple of times. Then I laid them all out to dry on a table in the garage, and set a fan blowing at them. I flipped them all over once after a few days.
Tubers, bulbs, and corms drying
On October 19, I cut all the leaves off, brushed off as much dry dirt as I could, and trimmed the roots up really short. Then I set them all back on the table, with any damp feeling spots towards the fan.
On October 22, I wrapped up each bulb in a piece of newspaper and set them all loosely in a basket that has lots of air holes. I’ll be storing them in the cold room again, I think, unless it gets too cold in there. But they’ll be in the dark all winter. We’ll see how this goes. Maybe I’ll do a mid-winter check and post photos of what they look like then.
Calla Lilies
Calla lilies are even less hardy; they’re only tough to zone 8! Plus, I had them growing in a planter, so basically no insulation protection. This is the first time I’ve ever tried to overwinter Calla Lily bulbs, so we’ll see how it goes.
I did basically the same as I did with the glads, cut the leaves off, trimmed up the roots, and set them in front of the fan to dry for a few days, turning them, so each side got some air.
I haven’t wrapped them up in newspaper yet. They’re currently just sitting on a paper plate because I’m not actually sure how you’re supposed to store them?!
I’ll do some googling and figure it out this weekend.
Dahlias
Ok, first, let’s start with a disclaimer: I don’t know ANYTHING about dahlias, and I don’t have much luck with them.
I’ve never tried to keep dahlia tubers over winter before. My grandma used to grow lots of dahlias when she was on the farm, and she stored her tubers. Similar to the Calla’s, they’re only hardy to USDA zone 8, so in Alberta, you have to dig them up if you want to keep them.
Dahlia tuber
In my “do first, ask later” style, I figured I’d just wing it. I’d heard that you should split the tubers up. But I didn’t really know how you should do it. I figured they must be like potatoes, basically…
Spoiler Alert: Dahlias are not like potatoes, just because they have tubers.
Anyway, I dug them out of the pots, brushed off the soil, cut off the leaves, and let them sit in front of the fan for a few days.
Then, I took a knife, split all the smaller tubers off the main one, and laid them out on a paper plate with the colour written on it (the only smart thing I did in this dahlia process) to dry some more.
When I packed up the glads, I wrote a letter for the colour: R for red, or Y for Yellow, on each chunk of dahlia tuber, and then rolled them up into a nice tidy roll of tissue paper.
THEN, I called my grandma and asked her how she used to store hers. She said she kept them in damp peat moss because if they DRY OUT too much, they won’t grow.
Remember the fan…?
She also said I could have just left them in the pots, cut the foliage off, and then kept the pots in the basement storage room for the winter. Good to know, now that they’re all sliced up and dried out…
I also watched a video from a flower farmer, and it turns out you can’t just slice off each tuber and expect it to do anything. You need to make sure each chunk you split off has an eye (ok, so that’s kind of like potatoes), or they won’t grow.
I think we can safely say that my dahlia tubers will not last the winter or grow new flowers next year. But as stubborn as I am, I’m not going to through them out yet… I’m going to keep them, and I will see if they do anything next spring if anything is left of them.
Did You Dig Up Your Flower Bulbs?
If you had glads and you haven’t dug them up yet, you might still be able to salvage them. We did have one night that hit =19.6ºC here last week, so that might have been too cold, but since the ground hasn’t frozen too deep yet, they might be ok.
If you want to watch the timelapse of me cleaning up my glads and destroying my dahlias, you can see it here on youtube.