Rooted Dahlia Cuttings: How to: Part 2
In Part 1 we talked about all the supplies we need- Now that you have all those things gathered (you did that right??)- Let’s get started!
Tubers potted up in a tray
So we need to generate some cuttings to root. Begin by potting up your tubers. You want to leave the crown area exposed (that’s the top part where the eyes on the tuber are). If you aren’t sure where the crown is- it’s right above the skinny part of the tuber- that’s the neck. The three parts of the tuber are the body (the fat or long part), the neck (usually skinner than the rest of the tuber) and the crown (this is the part that attaches to the stem).
Remember you can use potting soil, sand, soilless medium, perlite- whatever you want to try- it just needs to be able to hold water so you get the tuber moist. It’s going to take a minimum of 2-3 weeks to “wake up” a tuber. Sometimes longer— remember that varieties that bloom later, take longer to wake up. They can be stubborn and take 2 months occasionally. So take this time into account in regards to when you want to plant out. It will also take 3-4 weeks to root your cutting.
3-5 weeks wake up time (average) + 3-5 weeks root time + 1-2 weeks to harden off = successful rooted cutting ready to plant. (add another 4 weeks if you like to pot up to a larger container after rooting) Take that time and back it up from your last frost date and you’ll know when to start.
Now- this is the point where people start asking for tubers to ship early because they realize they are suddenly “behind!” Actually, think of it like this- it’s much less stressful. Don’t worry about trying to make a ton of new plants off new to you varieties in their first year. Just plant the tuber or rooted cutting (whatever you bought)- grow it and evaluate it. Then you can make plans to expand it the next year. I find this method works really well if you are in a hot/extreme climate. You don’t want to waste time multiplying a variety if it doesn’t work well in your climate. So (like I mentioned in part 1)— patience is a big part of this process. You’ll thank yourself in the long run for taking the slow route!
You’ll need to keep your potted tubers warm- you can do this via heat mat or a heated room. If you use a heat mat, make sure you have temperature control. I’ve found too often that I end up rotting tubers this way. I switched to using a heated room a few years ago and I find that it’s a much more even heat and works better. A small closet might work for this.
After a few weeks, you’ll begin to see green sprouts. Once the sprouts are about an inch and a half long, you are ready to “pull” as we say in dahlia lingo.
Prepare your rooting medium (see part 1 for options) and wet it down. You don’t want it sopping wet. Wet enough where it’s not going to dry out for a few days. This level of moisture is going to be a bit different for everyone because of different environments so experiment a bit. After you have prepared your tray you are ready to take your first cutting. You want to firmly grab the sprout at the base right before where it attaches to the tuber, then wiggle it a bit and it will pop off. If a bit of the tuber comes off too- that’s okay. Insert the cutting into your rooting medium (if you are using a rooting hormone, this is the point where you dip it in there). Make sure the cutting is stuck in at least 1/2”- you can go deeper if it’s a taller cutting.
The cutting looks small but I’ve found that taking them at a younger stage works better- I’ve achieved more consistent results this way. Now continue taking anymore cuttings that are ready to pull. After this, place a humidity dome over top of the tray. You want to keep the humidity high during this time. Then place under lights and on top of a heat mat or in a heated room under lights.
Check your cuttings once a day to make sure they aren’t drying out. After about 2 weeks, gently pull on the cutting and see if you feel any resistance. You can also look under the bottom of your tray/pot and see if you see any roots. Once you’ve got roots, you can lift off the humidity dome. Keep growing under the lights (and on the heat mat or in heated room) for another few weeks. Once you’ve got a good root system you can either pot up into a larger container and grow on or harden off and plant outside if you are past your last frost date.
Once your potted tubers start producing cuttings, you’ll need to check every few days to see if there are more ready to pull. Once you pull the first one off, the tuber will usually produce 2 or more for the next round. This is how they multiply quickly.
Remember that rooting cuttings is all about environment so if you fail the first time, make some adjustments— try a new medium, adjust your temperature up or down. Water less or maybe more- Each environment is different so there’s no 100% full proof method (no matter what anyone says)- Each environment has external factors that are out of your control so you have to adjust around those. Keep trying- Dahlias are a great plant to teach propagation techniques. You’ll have it figured out quickly!
Rooted Dahlia Cuttings: How To: Part 1
I know that I’ve written on this before but I’ve learned a lot through the years and wanted to share an updated tutorial of sorts on taking dahlia cuttings.
This is Part 1:
To begin: You are going to need a few things-
1. Grow lights- You can use ordinary shop lights. I suggest one warm and one cool bulb to get a broader spectrum of light. You can also buy actual grow lights (I’ve gotten affordable ones through Sunco recently). But unless you are taking these cuttings during a time of year where you can do it outside, you’ll need lights of some form.
2. Rooting medium and containers. You’ll need some sort of container to root your cutting into- I suggest getting some plug trays. The container doesn’t need to be really big, in fact it’s better if it’s not. It would take a long time for the cutting to fill up a 4-5” pot. So a plug tray that’s an inch or two in plug size is ideal. Greenhouse Megastore has great options.
Rooting medium can be many things and I suggest trying them all if you are brand new to this. Some people like a good quality potting soil, some go into straight perlite, or even sand. Some people like a custom mix of all three. I’ve even seen people use a small vase of water. Personally I like a potting soil mix that is heavy on compost and peat. This holds water well. You don’t want your media to dry out too fast.
3. Right conditions: You’ll need somewhere that can be kept between 65-70 degrees. You can use a heat mat under your cuttings. You can put them in a room with additional heat. You are looking for the soil temperature to be in this range.
You’ll also need humidity. Remember the cutting has no roots at first so you have to keep it moist so it won’t wilt. You need to keep the humidity high enough for it to not wilt while it’s forming it’s new roots.
4. Patience- Yes, this activity requires a bit of patience and perseverance. There’s a good likelihood that the first ones you try- some won’t work. 100% success rate almost never happens. We usually have about 5-10% of each full try fail or just take so long to root that we toss them before they can. So remember that this is a process of figuring out how to get the right conditions for your cuttings because everybody’s set up is different- You just have to keep tweaking it.
Other helpful things:
1. Rooting Hormone- dahlias will root without it. But you can speed up the process and get faster and more vigorous root growth with it. Pretty much any kind of rooting hormone will work. I like Hormodin 3- this has a high concentration of IBA- Indol-3-butyric acid. Hormodin 1 and 2 will work just as well but 3 has a higher percentage of IBA. Now you can get too much IBA, however, the amount contained in Hormodin 3 doesn’t run into those too high numbers.
2. A fan- if you are using a grow room set up, a fan is a great idea to promote air movement which keeps powdery mildew down and can help with fungus gnat control
3. Mosquito bits- Soak these in a gallon of water and then water your cuttings with it- this will help kill the larvae of fungus gnats. You can also buy Gnatrol (but it’s expensive). The mosquito bits do the same thing.
4. Labels- We use vinyl blinds written on with pencil— these don’t fade and they are cheap!
Last but definitely not least: You are going to need some tubers to propagate from. So go grab some tubers out of winter storage and join me back here next week and we will get started on the actual process of taking a successful dahlia cutting!
Back to the Basics with Dahlias
Get back to the basics with dahlias to ensure success in your garden this summer!
If you are new to dahlias this post should give you some help to get started. If you’ve been growing a few years, this will be a good refresher course. So Back to the Basics we go!
1. Before you buy a tuber, survey your yard, add any compost- let’s get our mindset in place. Growing plants is a life long journey. Perfection won’t be gained in year 1 or 10 even. It’s a journey we embark upon to learn more about the natural world, to bring beauty into our lives, to teach us many lessons (least of all patience), and to share the beauty/bounty we grow with others. There is no succeed or fail, only lessons learned, knowledge gained, and relationships formed (with people and nature).
KA Mocha Katie
2. Remember what plants need- Every plant needs light, water, and something to grow in (usually soil). Dahlias specifically need full sun (6+ hours a day), rich soil with good drainage, and moderate water during the green growth stage and more water when blooming.
3. Dahlias need support. Most dahlias are tall plants- tall enough to need support. So place a stake or wire cage when you plant or install support netting over a full row.
4. Dahlias are hungry plants. So don’t skimp on the compost or fertilizer— Make sure your soil has enough nutrients to feed your plants properly. They prefer soils higher in phosphorus and potassium, lower in nitrogen. Too much nitrogen will create lush green plants with little to no blooms. Get a soil test from your local extension so you have a baseline to begin.
5. The more you cut, the more they bloom. I often hear of new growers being afraid to cut their blooms but the more you cut, the more the plant is triggered into producing more blooms! If you pinch out the central growing tip when the plant is around 18”-2’ tall, it will cause the plant to branch and give you more stems.
6. Dahlias are the ultimate generous gardener plant. Place one tuber in the ground in the Spring and dig up a whole clump in the fall. Or if you live in a warm climate, overwinter them in the ground and divide your generous clump in the spring and turn all your friends into Dahlia Lovers too!
Sonic Bloom
So if you read through this and thought- but I still didn’t have the results I wanted with my dahlias.
***Read through again. Really look into each step and evaluate your growing. The majority of issues with growing dahlias can be traced back to the simplest things. ***
For example, for years, I always told myself- I’ll get the netting up before they get too tall! HA!!! And for years I had so many floppy plants- lost loads of stems that I could have sold! So now I put my netting up as soon as a row gets planted. The planting is not finished unless the support netting has been installed.
For the first several years, I didn’t soil test and I had lackluster blooms. They would be small or misshapen. I finally tested my soil and found I was very low in the crucial nutrients that create bountiful blooms.
It took me several years to really believe that I could cut 2’ stems on my dahlias without damaging the plants. But then I grew a variety that was 8’ tall. I had to cut long stems in order to keep it manageable. That taught me that if I cut the first stems long, then I would continue to have long usable stems throughout the season (instead of short weak ones).
All that to say— Don’t Ignore the Basics!!! When I see new growers who have bountiful blooms on healthy plants, I can always trace it back to following the basics.
So go grab a few tubers to try this year and then over the next few months, begin to plan how you will implement the basics in your garden. Follow along with me here, lots more info coming. Also lots of info already available.
If you are ready to go deeper, it’s time to think about joining our Dahlia Growing For Beginners Virtual Course!
A Dahlia Year In Review: 2024
January is always a time of reflection and planning on the farm. I’ve been looking back at last year and forward into 2025. It’s going to be amazing for dahlias- I can just feel it! However I didn’t want to let the opportunity pass to write a review of 2024. It was interesting to say the least….
The year began in March with removing the covers from our over wintered dahlia trial. The plants were already sprouted when we removed the tarps in early March. We even got lucky last year and only had one mild frost after the tarp removal. This nipped the plants back just a bit but not much.
We also took loads of cuttings last spring to fill up our field with new varieties. We worked in a makeshift grow room last year and I’m so thankful for a much upgraded set up this year.
We planted all through May and June. We also harvested blooms during this time too- This was a new experience to be harvesting and planting at the same time. But we had blooms off our early over-wintered during May through June. At the end of June we cut those plants back to give them a break during the high heat of July. We also had some extreme heat temps in June which did cause some loss. Some of the later tubers we planted didn’t make it, they literally cooked in the ground. The rooted cuttings however did much better. Because they already have roots when planted- they establish much faster.
Left: Over wintered dahlias budding up
Center: First Blooms!
Right: Over wintered dahlias cut back and in need of some weeding
July and August came and went and we just did what we always do— Remained consistent in feeding and managing pests. It’s the only way to get through the yuck of summer and leads to beautiful fall blooms.
September came and we cut buckets and buckets of to die for blooms!
It was amazing until it wasn’t. In less than 24 hours, Hurricane Helene came through and left a wide swath of damage. We were lucky- most of the damage was in our woods with fallen trees. We still have damage to our barn to fix but it’s nothing compared to what so many experienced just an hour north of us.
From a dahlia standpoint, it did end our season early. We got about another week’s worth of blooms. We lost a lot of plants to rot in one of our fields that was just beginning to bloom for the season- several 1000’s of dollars worth of loss. We won’t really know the full loss until we pull back the tarps this March to see what tubers still remain. I’m fully planning on making extra cuttings to replace the ones that rotted. It was hard to tell at the end of the season. Several rows had 20-30’ of rot and then the rest would be fine. Overall the hurricane was also a big contributor to lower tuber yields this year too.
But that’s another reason I’m thankful for an upgraded grow room this year. We are growing lots of rooted cuttings for our farm and for sale!
Here’s to 2025— May she be free of extreme heat waves and devasting hurricanes!
Planning Your Cut Flower Garden With Dahlias
We all know that dahlias are the queen of any flower bouquet but every bouquet needs some supporting players. Earlier this week, I asked my crew what their favorites annuals were to plant with dahlias in a cut flower garden. I know every one is planning their summer gardens right now so read on for a bit of inspiration.
We are going to go in alphabetical order here:
Asters: These are a great early fall bloomer to complement dahlias. They do work better if you are a cool zone 7 or lower. Sadly I haven’t seen a lot of success for these in extreme heat climates. You need to know that they must be planted early in the season (April/May). They have to establish under shorter day lengths so plant with enough time for them to bulk up before the summer solstice. The decreasing of daylength after the solstice is what initiates the buds on them—therefore leading to a beautiful early fall bloom.
My Crews Top Picks:
Melissa- Tower Violet
Baylee- Tower Salmon
Celosia: These beauties are the opposite of asters. They love the heat! If you are in a cooler climate, you could try them inside a hoophouse, even a small backyard one might give you the extra heat needed to grow it. Celosia can be succession planted too- you can seed a set of them every month from March through July if you live in an area with a frost date of late October or later. Earlier than that, you would want to quite seeding in early June. Seeding transplants is definitely the way to go with celosia, you’ll get better results than direct seeding. But make sure to not leave your transplants in the trays too long- they don’t like to get rootbound.
My Crews Top Picks:
Melissa- Chief Persimmon
Nonah- Dragon’s Breath
Baylee- Flamingo Feather
Cosmos: You can never have too many cosmos in our opinion. We had a hard time picking just a few varieties! I like to direct seed cosmos. You can do transplants but they do very well from a direct seed and it saves time babying plants. Wait until the soil is very warm- don’t rush these into the ground immediately after your last frost date. Give it a few weeks and then they will pop out of the ground within a few days. If you choose taller varieties you may want to support or net them so they don’t fall over.
My Crews Top Picks:
Melissa- Rubenza, Bright Lights
Baylee- Double Click Bi-Color Violet, Apricot Lemonade
Nonah- Double Click Bi-Color Violet
Sophie- Rose Bon Bon
Gomphrena: Who doesn’t love the fun pop of color that gomphrena brings to a bouquet. They have such a sense of whimsy. You can succession plant these too if you want a continuous bloom all summer. Just start a new set of seeds about every 4 weeks until July. Begin seeding 4 weeks before your last frost date. Then plant after the frost clears. Pinch out the center when they are a few inches tall so that they will branch and give a lot of stems.
My Crews Top Picks:
Melissa- Firecracker
Baylee- QIS Pink
Nonah- Las Vegas Mix
Marigolds- These are the champions of fall. Such tough and hardy plants and there are so many new ones on the market these days. I grew to love marigolds again last year when we planted White Swan. Gorgeous butter yellow color and doesn’t have the strong smell of other varieties. Marigolds have a strong scent to their foliage and you either love it or hate it. These can be direct seeded very easily or transplanted- they work well either way and will sprout in a few days.
My Crews Top Picks:
Melissa, Baylee- Gem Series (specifically Lemon Star)
Nonah- White Swan
Zinnia: An easy to grow favorite! Zinnias really fill up a bouquet and the wide range of colors gives something for everyone! Start from direct seeding if your soil is sufficiently warm or transplants if you want to start the seeds early. Zinnias are another good one to succession plant. They tend to get fungus after a few weeks of blooming so good to plant multiple successions to have fresh blooms without brown spots.
My Crews Top Picks:
Melissa- Oklahoma Ivory and Benary Wine Red
Baylee- Ballerina
Nonah- Cherry Zydeco
Sophie- Queen Lime Red
So what are you going to grow with your dahlias this summer and fall. And most importantly— do you have enough dahlias?? The queens are important and there must be enough beauties to hold pride of place in your bouquet. If you need more- check out our dahlia tubers and cuttings!
