Late March I headed up to the lake to grab my dahlia tubers and to begin preparations for cool weather loving flower planting time. There are numerous methods of storing dahlia tubers between first and last frosts. The last 2 years I have used a space-saving process of dividing tuber clumps in the fall then wrapping them in plastic wrap. They are stored at 45 degrees in a little beverage fridge in the crawl space at our lake.
You just don't know exactly how tubers will fare over the months of storage. Last year only a couple tubers were unusable due to either dehydrating, breakage, or rotting. This year, unfortunately, about 10% needed to be tossed. I think that either the increased number I stored in the fridge or possibly not being dried quite as well as the year before, made some of the tubers too wet. I have updated my database with any changes. Being stored at 45 degrees since late October, most tubers are not showing off their "eyes". There are always a few that do not eye-up at all. Over the next couple weeks of being in somewhat warmer temperatures, most of the rest will start to show off their readiness to sprout.
You may notice that my tubers look a bit dusty. That's because we roll them in cinnamon before wrapping them up. Cinnamon is a natural anti-fungal, plus it's smells great!
In mid-April I will encourage tubers to wake up to be sure they are viable (will eye up) if they do not already show a clear eye. Without an eye, roots may grow, but no stems and flowers. If needed, one way to encourage tubers to come out of dormancy is to cover them with damp potting soil or peat moss. Then wait a week or two. It's fun to uncover them and see the eyes and even sprouts.
Of note - until a dahlia has a stem and leaves, great care must be taken to not overwater the tubers. Tubers can easily rot in the ground if too wet. Just damp is the key.
It was just nice enough outside on Saturday to do a 2nd sort of the tubers. It felt great, although a bit chilly, to be outdoors. I added peat moss around the tubers then tucked them into the garage. I monitor the temperature to be sure it stays over freezing. The garage should stay between 40-60 degrees over the next couple weeks. It will be just warm enough, I think, to encourage eyes to develop, but not too much growth. It's not quite time yet to encourage more than eyes. If a jump-start on growth is desired, dahlias do not need to be started more than 4 weeks or so before expected planting. It is best to wait until the soil is at least 55 degrees to plant out. 60 degrees is even better.
There are a couple options if you wish to get a head start with your dahlias.
I will go into more detail in another post, but basically you can.
Keep them cool until planting.
Wake up the tubers a couple weeks ahead to encourage a bit of eye growth.
Wake up the tubers 4-6 weeks ahead then put into pots under grow lights once they begin sprouting.
Last year I found that the dahlia tubers I woke up at the beginning of April did not grow and bloom quicker or better than the ones I woke up in early May. One seasoned Minnesota Dahlia Society member in zone 4b recommends April 15 for starting tubers for mid to late May planting.
After the tubers have been woken up enough to see eyes, sorting the extras will begin. Until I know if a tuber is viable, I will not give any away. I'd hate for someone to be disappointed by getting a "dud".
Upcoming I'll be posting what to do with your tubers before it's time to plant them.
