Rooted Dahlia Cuttings are a bit different from a tuber. You are planting an actual green plant with roots instead of an ugly brown root! They both produce gorgeous flowers - they just begin differently.

Rooted cuttings are small when they first arrive. Usually only a few inches tall. Different varieties grow at different rates. You can have little top growth but a full root system. You could plant directly if you are past you’re last frost date but your chances of success get much higher if you pot the cutting up first. Grab some good potting soil and 3-4” pot. If your cutting comes in a pre-fabricated plug like a root riot or the paper contained elle pots- tease as much of that off as you can. On the elle pots, you can just cut the paper and leave it on there. You just want the roots to have freer access to move and expand. If they get restricted, this will inhibit tuber growth and causes the “mass of roots” effects instead of tubers.
Place the potted cutting into a shady/part sun place. Remember that most rooted cuttings have come out of a grow room or greenhouse before shipping and need to be hardened off first. So shady/part sun for a few days and then full sun until the roots fill the pot.
I recommend using a light fertilizer after your cuttings have been potted up for about 10 days or so. I’ve found that they use up the “goodness” that is contained in the pod or dirt they were rooted in very quickly.
Water when almost dry. It’s very easy to rot out a cutting so run it on the dry side but don’t let it completely dry out.

After the roots have filled the pot so that the dirt stays together when you pull it out of the pot, you are ready to plant (usually 3-4 weeks). Plant into your prepared garden bed, landscape or large pot (7 gal minimum). Remove the bottom set of leaves and plant so that the node from those leaves is underground. This will help encourage tuber growth.

Water well after planting and pay close attention to moisture levels for the next 2 weeks as it is getting established. Be careful about planting tubers and rooted cuttings near each other because of their different water needs. You can plant tubers a few weeks before your rooted cuttings (say when you pot up your rooted cuttings) and they will be at the same stage by the time your rooted cutting is ready to plant. Therefore requiring the same amount of water.

I get asked a lot about how to get good tuber growth off rooted cuttings. I’ve noticed 2 things:
1. You need to fertilize them as much as tuber grown plants. When I hear of cuttings that didn’t grow tubers, I usually begin digging into the grower’s fertilization plan (and often they don’t have one) or they didn’t fertilize enough. Tuber grown plants won’t make any or many tubers either if you don’t fertilize them. Plants need food to do their thing!
2. Not getting any tubers can also be problematic on newer bred varieties. I’m speaking from observation over a few years here. I’ve tried newer (unicorn) varieties from very reputable breeders who are not in my climate and had very poor results at first. I got the “ball of roots”. I managed to save the root balls- you can put them in a pot with dirt or store in vermiculite. You need to be sure they don’t dry out so humidity is important!! Then I made cuttings off the root balls- so year 2 I got a few tubers- small and not many but some. Replanted those tubers in year 3, got much better tubers. Year four I replanted tubers and rooted cuttings off the year 3 tubers and got good results. So my observation is that new varieties bred in different climates are going to need time to adapt.
So why doesn’t this happen with any variety that is bred in a different climate? It does to a degree. Those of us growing in hot climates know that certain varieties do better here. But also because some varieties have been around so long that their stock has literally been all over the country and mixed around so much that it acclimated.
This is purely observation, I don’t think anyone has done a scientific test on this. But over so many years of growing, I’ve noticed that varieties do adapt to where they are grown.

Planting Rooted Cuttings

Let’s Get Planting!