Checking stored flower bulbs

Several weeks ago I blogged about how I store dahlias. Did you keep some of yours too? If you haven’t already done so, now’s the time to check on them to see how they’re doing. Serious dahlia growers begin planting their tubers in mid-March, in pots and in a greenhouse of course.

I opened mine up right after the polar vortex blew through a couple of weeks ago. They were in a spot that normally stays cool but never freezes. However, this fall I rearranged boxes and stuff in the garage. Without realizing it, doing that must have changed the airflow pattern and allowed cold air to settle in the spot where I stored my dahlia tubers. I didn’t have a thermometer in that area but I knew it got cold because the storage bags were partly frozen. That’s not a good sign.

They didn’t look too bad when I opened them up to take a peek, but some looked to be partly frozen. The outside layer of damp sawdust was lightly froze. Instead of warming the tubers up to thaw, I moved them to another more temperate part of the garage to slowly warm up. Today I finally brought them out to see how they were doing.

It's very easy to tell the damaged tubers from the undamaged.
It’s very easy to tell the damaged tubers from the undamaged. The one on the left was frozen.

As suspected, most of them were damaged beyond salvaging, I’m looking at about an eighty percent loss. The ones that survived look healthy though. I’ll re-pack the good ones in fresh sawdust and compost the rest.

I also had some elephant ears tubers in storage, those I kept in the pots that they grew in last summer. They look pretty good. I gave them a small amount of water whenever the soil looked really dry — maybe once every other week or so. In the spring I’ll knock them out of the pot, divide them and replant.

You can't see much in this photo but the elephant ear roots are looking good.
You can’t see much in this photo but the elephant ear roots are looking good.

Other large pots have cannas that I stored the same way as the elephant ears, right in the pots they grew. They got some water through the winter too but not as much as the elephant ears. I wanted to keep them a little on the dry side so they wouldn’t get water logged and rot. Remember, they are dormant and not growing so they don’t really need much water. On the other hand you don’t want them to dry out and shrivel up. It’s something you have to learn trough experience. I usually ere on the side of less water.

The canna bulbs are in fine shape at this point in time.
The canna bulbs are in fine shape at this point in time.

Unfortunately, we lost a large geranium to the cold. It was one that we’ve been saving and taking cutting from for years and years.  During the most recent warm-up, we set the potted plant out on the front porch and — you guessed it — forgot it was there and it froze overnight. There may be some dormant buds that survived, I’ll let you know how that turns out.

Bob

 

 

Digging dahlia tubers late

Last week I talked about my potatoes that I dug up very late in the season. What I didn’t mention was that same day I also dug my dahlia tubers that were still in the ground. Turns out they where in fine shape shape as well.

It makes perfect sense that the tubers would look so nice.  The ideal storage temperature for dahlias is around forty degrees Fahrenheit and that’s about what the soil temperature was. I checked the soil temperature in my garden again this morning and found that even now, during the first week of December, it’s running about 40F.

What kind of surprised me was how warm the soil is even with the colder than normal November we experienced. Looking back on the several weeks,  a pretty good set of circumstances lined up for my dahlias. First, the tops were froze back by the frost back i October. Then I left them in the ground for well over a month. That allowed the tubers to develop healthy “eyes”, just like the eyes on a potato. With strong eyes, my tubers should make good, strong growth next spring — that is if I take good care of them over winter.

This is a typical dahlia tuber but they come in a wide variety of shapes and sizes.

There’s a few simple tricks to keeping dahlias over winter. The first is to store them at the proper temperature and we already know what that is — just don’t let them freeze.

The second crucial factor is humidity. If left out in the air during storage, the tubers will dry out due to the low humidity we typically have in our homes in the winter heating season. So the solution is to store them in air tight containers. For a small amount of tubers, maybe under a hundred or so, I find keeping them in zip-loc bags is a good way to go. I usually separate the clumps of tubers into singles, then place one or two in each bag. To maintain good humidity I add moist sawdust to the bag. If you have more that one tuber per bag, the sawdust also keeps the tubers from touching each other. While you’re at it, add a tag so you know what variety it is.

Even though I had success in the past using peat moss, potting mix or garden soil, I’ve found that sawdust works best for me. I’ve heard of people using shredded newspaper but have never tried it. However, with so many people opting to get their news online, printed newspaper is getting harder and harder to find these days . You can easily solve that dilemma by subscribing to Detroit News home-delivery, but I digress.

The third and final secrete is to check on them once in a while. Open them up and make sure the packing material is still moist. Also, toss any rotting tubers you might find. It’s pretty disappointing to open them up in the spring only to find out your tubers were ruined due to neglect over winter.

Those plants you bought from the garden center and planted in your garden, most likely grew a set of usable tubers. Since soil temperatures are still hovering around 40 degrees F, it may be fun to check in your garden to see if your dahlia tubers are still good. Dahlia farms are asking $3.00 and up for each tuber (not including shipping) so it may be worth your while to poke around in the garden. Let us know in the comment section what you find.

Bob