Propagating Dahlias from Cuttings: Part 2

Welcome to part two of the notes from my dahlia cutting experiment. If you are just joining us, Propagating Dahlias from Cuttings: Part 1 will help you get up to speed on this project. And, as always, if you have any questions about our process or results please let me know!

February 28: Since I last wrote, I've been keeping an eye (pun intended) on those cute little dahlia cuttings. I'm sad to say, they didn't look cute for long...

I took my dahlia cuttings and put them in a nice warm place in the greenhouse, and I tried to keep them happily damp, but not too wet and ...they... wilted. They looked pretty bad. I stepped in on the second day of wilting and trimmed off the remaining lower leaf pairings, which left most of the cuttings with just a couple leafs at the top of the sprouts. 

Cuttings on Friday, Febraury 24, day 2 after having ben cut off the tubers. They started looking very wilted. By the following day I thought I was losing them. On day 3, I cut off their lower leaves, hoping to help them root faster. 

And then, on day 5, the cuttings started looking better. And then they perked back up again. Something started to work.

The dahlia cuttings on day 6 are looking much healthier! They are standing up. The process seems to be working. 

March 1: But, what was more encouraging was what was happening to the tubers I'd taken them from. I looked carefully at the sites I'd taken the cuttings from. At each little sprout stump, there were 8 or 9 new sprouts forming. That was also true for any place that a developing eye's sprout had been accidentally scraped off. (This happened on several of the slower growing tubers when people were helping me water the trays. I think the humidity domes were pushed aside, rather than lifted off. Any little eyes that had sprouted, but that were not easily viewable by my helpers were decapitated.)

Here are some of the dahlia tuber sprouts after the first cutting was made. The dark black stump was the site where the first sprout was taken. The red and green sprouts are faster-growing sprouts that came in just after the first cut. They will also be made into cuttings. 

This new knowledge got me thinking about pinching back the very first sprout on more tubers at an early stage to encourage even more sprouts to grow. Two things happened when I tried to decapitate them hastily myself. On one plant, I successfully broke off the eye's sprout and left a new stump just like the others. But on another, I accidentally pulled out what seems like the whole eye. I'm thinking that can't be good, but I'll let you know what happens. Next time, I'll use my sharp little scissors (the same ones I used to take the cuttings!) to shear off the tops of the little eye-sprouts and avoid pulling the sprout right out of the tuber again. 

March 14: Today I did a little work in the greenhouse in preparation for Blizzard Stella. I mostly just watered everything and made sure the door to the classroom was left open in case we loose power again. Before I left I noticed that one of the dahlia's I've been taking cuttings from seemed ready to go into the ground. I cleaned out a nice wide pot and filled it with a combination of damp potting soil and seed starting mix. I gently lifted the tuber out of the tray and noticed right away that there are already four tubers where there was one before. It also had a bunch of roots. A peek under the slotted trays revealed the other tubers that are also putting down long roots. I planted the tuber clump in the prepped pot and made a sweep to get rid of those tubers that haven't shown any signs of growth. There were fewer of these "bad ones" than I thought there would be. Just four went into the trash. As of today, I have 12 new plants from cuttings- I'm getting close to doubling the number of plants I'd have if I hadn't taken the cuttings. 

March 14th growth on dahlia tuber started on January 25th. I may take one or two more cuttings from this plant and then let it grow on its own until I can plant it out. 

March 18: We are up to 18 dahlias from cuttings now! A few of my tubers were from short-stemmed landscaping varieties. I saved them to plant them out for decoration, but I'm hoping that most of these cuttings are from the taller plants. It will be fun to see what happens. Tomorrow I'll take the rest of the tubers out of the trays and pot them up. I think they'll be even more productive with more room to grow.