Tree Dahlia Propagation

I have for the first time successfully grown a few tree dahlias. They were cuttings, they grew really tall, they made flowers, they were lovely. Now the flowers have gone their separate ways.

Do I cut them down now? Down to the ground? And in making cuttings for propagation, do I just cut below the nodes and keep them about six inches high or so? And are there some parts of the stem that are better for cuttings than other parts (the bottom, the middle, the top?) I'm sorry, I haven't done this before and tree dahlias are new to me.

Thanks!

hiya grapesie,

Cutting them down after they are finished for the year is one way to insure a strong regrowth. I cut mine down to about 18in when they are finished and them cut the rest down after new growth appears in the spring. As far as propagation goes, root cuttings are the only way I know to increase their numbers during the dormant season. Stem cuttings are possible during the growing season but are difficult to get to produce roots without tons of mist and bottom heat.

I've recently made two root/stem cuttings and shipped them to members of this forum. I just took a spade and separated a healthy trunk and the roots connected to it. The reason for leaving some healthy trunk is that it also stores energy and will help the plant recover and grow. When the new cutting starts to show growth at the base you can cut the rest of it down as the plant is now actively growing.

Good luck, keep us posted on your successes and please post pics of your plant(s).

best,
don