Cuttings Versus Tubers- Which is Right For You?

Rooted Cutting Sale Going on Now!

Rooted Dahlia Cuttings! They’ve become all the rage recently. If you are new to the dahlia world or have only grown tubers- you may be wondering what all the fuss is about?! Well let’s see if we can de-mystify that a bit.

First off- What is a tuber and what is a rooted cutting? Let’s get real basic here.
A tuber is the underground tuberous root that is produced by a dahlia plant during one growing season (they produce tubers on their first year, you don’t have to wait until the second year- that’s a common misconception I hear often.) The clump of tubers is dug up at the end of the growing season and then washed off and divided. They are stored through the winter and replanted in the spring.
A rooted cutting is when you take a tuber and pot it up early in the growing season. When it sprouts, you cut the sprout off and put it into a rooting medium, keep the humidity and temperature right and it will root in a few weeks. Within 6-8 weeks, you have a plant ready to put in your garden. You can keep taking more cuttings of this same tuber. This is how you can quickly multiply your own dahlia stock.

So which should you choose? Well there are pros and cons to both. Let’s take a look at some of them:

Spring time and receiving your tuber/cutting:
Tuber- You receive tubers in the spring sometime and then you plant when you past the last frost date for your growing zone. They hold pretty well if you need to wait a week or two before planting.
Cutting- You’ll need to care for them when you receive them and you’ll need to plant (or pot up) not too long after receiving it. However, cuttings are usually shipped when it’s the right time for your growing zone.

Planting your tuber/cutting:
Tuber- You’ll plant your tuber in the ground and then you wait- at least 2-3 weeks, sometimes more. Some varieties can take 6-8 weeks before sprouting although most are in up 4 at the most. In this time you have to make sure it doesn’t rot and also that your soil doesn’t get too hot (the heat temperature issue isn’t usually bad unless it’s high summer and your soil is extremely warm. I didn’t used to think this was an issue but I saw a lot of tubers cook in extreme heat this past summer on a lot of farms - even some on ours.)
Cutting- You plant it and you have a plant- cuttings definitely have an instant gratification factor. You will need to water it and care for it but it’s not any different than any other plant. Since you are planting a cutting, you have at least a 2 week jump on the tuber, sometimes more if it’s a later sprouting variety.

Growth Process:
Tuber- If your tuber gets established before harsh weather (heat, drought) comes, then it has a fairly good chance of making it through. However one thing about a tuber is that the plant will use the food provided by the tuber and can be slower to push out actual roots to keep feeding itself. This can have a significant impact on it’s ability to survive harsh weather conditions.
Cutting- A cutting has roots from the moment it starts to push them out in the rooting process. Then when it gets into the ground, it immediately starts to push roots out to establish itself.
This is where I saw the advantage of a cutting over a tuber for a harsh growing climate like mine. Our weather during the planting time is very erratic- some years it’s so wet, we can’t plant for weeks. Some years it’s so dry that the tubers take weeks longer to sprout. But when we started planting more cuttings, we were able to get a consistency in our crop that we hadn’t seen in years past. Not to mention the timing- we could plant wet or dry as long as the beds where prepared early.
Putting cuttings in and using a bit of irrigation if we were in a drought works better than tubers baking in hot soil. The water used to irrigate the cuttings also helps cool the soil. If the weather is the opposite- super wet- well the cuttings love the water and grow faster. You do need to ensure good drainage but good drainage is growing 101 for dahlias anyways.
Over the past 2 years we’ve made a move to planting more cuttings than tubers. Our field was over 60% cuttings last year. I firmly believe the resiliency of those cuttings is what got us through the extreme heat wave. The plants had good root systems because they were weeks ahead of the tubers. The tubers where baking and just disappearing under the soil because of the extreme heat.

Bloom time:
Tuber- Most bloom times you see posted are from planting a tuber in the ground and then growing to a full bloom
Cutting- You’ll get blooms sooner, by at least 2 weeks because you planted a plant instead of the tuber. So if you want color in your garden quicker, use cuttings.

End of Season:
Tuber- You cut back your plant and proceed to dig a nice clump of tubers.
Cutting- You cut back your plant and proceed to dig a nice clump of tubers. There’s a myth out there that rooted cuttings don’t produce tubers but in our many years of growing experience this has not proved to be true. Yes, sometimes you dig up a dahlia and there’s nothing there or there’s only your original tuber. But our experience has been that we get the same percentage of plants that produce clumps of tubers from rooted cuttings as we do from tuber planted dahlias. How many tubers you get at the end of the season depends on several factors (genetics, fertilization, growing conditions, etc. ) but whether you planted a cutting or tuber isn’t one of them.

So what do you choose? Honestly I would give both a try. I am seeing that cuttings are working better for harsh growing conditions. Also they allow us to keep our planting schedule which is important because we try to time our dahlias to bloom when our customers want them the most. If you decide to try both and you are planting them in the same area- plant all your cuttings at one end and your tubers at the other. Your cuttings will need water at first and you don’t want to rot your tubers out. This is what we do when we have a mixed bed of tubers and cuttings. Mixing in the same bed will really show you the differences and is a great way to observe and experiment.