Starting Dahlia Tubers Indoors - 20 Days Later - Early May 2026

In mid-April, I began the process of potting up my dahlia tubers for the year.  They are MOSTLY tubers that I have grown in previous years that I dug up and stored over winter using the Saran Wrap method.  I began by trying to divide the tubers into viable 'clumps'.  After watching a bunch of YouTube videos, I learned that tubers need to also have part of the 'neck' attached to them in order for an 'eye' to sprout.  Without that 'eye', the tuber is 'blind' and won't ever put up shoots.  

I ended up potting up close to 100 tubers in one-gallon nursery containers and after watering the potting mix (just a little bit), carried them all down to my basement to begin what I call 'sprout watch'.  

From what I understand, these tubers (if they are viable) have enough energy stored in them to produce the initial growth and don't need too much water in order to begin their annual cycle.  Too much water and you end up rotting the tuber, so I used a loose, dry mix and after that initial watering, I haven't touched them.

Of the (close to) 100, we're now at 62 containers that have sprouted.  Below are some photos showing the current state of this collection.  First up, is a set that I keep in the dining room.  This window gets the best light and so these are the furthest along.  The tips on some are a few inches tall on others are just barely above the soil.  

Below is one of the new (to me) tubers:  Creme de Cognac.  It is viable, so that's good.

Down in the basement is where I keep the rest of them.  I start them all on tables and when I see some 'action' in terms of green tips emerging from the potting mix, I move them.  Here, below, is the table of the 'no action' set (so far):

Once I see green shoots, I move them over to the windows.  Below you can see a couple of our window well stations filled with one-gallon containers with green shoots of dahlias:

With 62 (seemingly) viable dahlias, we now wait for the balance of them to either come alive or end up being blind.  

Going into this, I was hoping for more than 50 and to know that I'm past that mark means that we'll have plenty of these to give away to family and friends.  

Also good to note that I started these more than two weeks earlier than I did last year when I planted them up on May 1st.  This year, I started in mid-April. 

Five weeks after potting, I planted them in the ground on/around June 10th.  

Soil temperatures (according to Greencast) for our Zip Code are in the mid-50s right now and are right close to the 10-year average.  I'd like to see the soil temps get closer to 60 before planting these out.  Ideally...before June 1st, but well-after the last threat of frost which history says is close to mid-May.