Expanding your collection of dahlia plants is easy and effective when you learn how to take dahlia cuttings. By taking cuttings, you can create more plants, resulting in an increase in new tubers and flowers.
I love growing beautiful dahlia plants and have been doing so for several years. But buying multiple varieties of my favorite dahlias can be expensive as I have paid over $30.00 a tuber for those highly sought-after varieties.
Luckily, I have learned how to grow new plants from dahlia cuttings. It is an easy way to get more plants without spending more money, which is a good thing seeing that I am a dahlia addict!
If you want to learn more about growing dahlias, be sure to read these posts:
- How To Plant Dahlia Tubers
- Starting Dahlias In Pots
- Pinch Out Dahlias For More Flowers
- Disbudding Dahlias
- Are Dahlias Perennials
What is a dahlia Cutting
A dahlia cutting is new sprouts with several pairs of leaves taken from the top of a tuber to propagate a new plant.
The cutting is then dipped in a rooting hormone before being placed in a growing medium to allow roots to form.
Why Take Dahlia Cuttings
There are several reasons why home gardeners take cuttings from dahlias. The most common reason is to increase the number of plants without purchasing additional tubers.
Another reason is that some dahlia varieties have tubers that are difficult to store over winter. You can propagate cuttings indoors over winter by taking them in autumn.
This is a great way to ensure you can continue growing the same variety the following spring.
There are various methods of propagating dahlias from cuttings. These methods involve taking a portion of the mother tuber and encouraging it to create a new plant.
Each method requires a different process, but all are effective ways to expand your dahlia stock.
Dahlia Propagation from Seed
The propagation of dahlias can be achieved through planting seeds, which will create a wide variety of new cultivars that differ from the parent plant.
Seed propagation is mainly used to develop and discover new varieties of dahlias.
Dahlia Propagation from Tubers
Propagation using tubers is the most common and well-known way to grow dahlias. This method creates a plant identical to the mother plant.
Dahlia Propagation from Cuttings
Taking cuttings from a dahlia involves taking a stem from a healthy mother plant and allowing it to root.
It is then dipped in a rooting hormone and kept in a warm environment where it develops a strong root system. This method forms a new plant that is identical to the original.
This post will provide a step-by-step guide on how to take dahlia cuttings to increase your stock of plants.
These instructions will help you understand how to care for your cuttings to ensure they root successfully and develop into healthy plants.
When to Start Dahlia Cuttings
If you want to propagate dahlias, the best time to start the process is in late winter or early spring.
Here in Missouri, I start waking up my tubers in late winter to take shoot cuttings in early spring.
To begin dahlia propagation, you will need viable tubers with noticeable eyes. You can either use your own stored tubers or purchase them online.
How to Take Dahlia Cuttings
Growing dahlias from cuttings is a simple process that can be done in just a few short steps.
Step 1: Gather Your Supplies
To take dahlia cuttings, these are the tools and supplies that I have successfully used.
- Viable Tubers
- Propagation Tray or Pots
- Potting Mix – I use Light Warrior Seed Starter
- Clean scalpel or sharp knife
- Propagation Kit with Root Riot Cubes & Clonex Gel
- Soil Thermometer
- Plant Labels
Step 2: Choose Your Planting Container
First, you will want to determine what kind of container to plant your dahlia tubers in. It does not need to be deep as the top of the necks will remain out of the soil.
A propagation tray may be the best option if you plan to take cuttings from many dahlia varieties. This type of container allows you to easily fit a lot of tubers into one tray, which can be more efficient and space-saving.
On the other hand, using individual pots may be more suitable if you only take cuttings from a few varieties.
Step 3: Plant the Tubers
Start by adding a layer of damp potting mix to the bottom of a propagation tray or pots.
Next, lay individual tubers vertically with their necks facing upwards so they are exposed above the soil. The neck is the tuber’s thin part with a small piece of the original root system.
Then, add a layer of potting mix to cover the tuber but not the neck. Gently water the soil to settle it in around the tuber.
Be sure to add a plant label for each cultivar so that you know exactly which variety is sprouting.
Then place them on heat mats set at 70 degrees in a place with natural or artificial light to encourage new growth.
Since dahlia tubers don’t like to sprout in cold environments, it is essential to maintain consistent, warm temperatures.
Typically, tubers begin to sprout with healthy shoots in about ten to fourteen days. However, all dahlias will vary in the time they sprout, some taking up to a month or more to sprout.
Step 4: Prepare the Trays
Before taking your first cutting, it is best to have the trays with drainage holes or a propagation kit ready.
If you use a seed tray, fill it with damp potting soil. Then, use a pencil to make small holes in each tray cell.
This is important because the holes keep the rooting hormone on the cutting from getting wiped away when you put it in the soil.
In my experience, I have found that using Root Riot Cubes yields the best results when propagating dahlias from cuttings.
Root Riot Starter Cubes are soilless growing mediums. The cubes hold the perfect amount of moisture and promote a healthy root system. (source)
Step 5: Make Labels
Creating a plant label for every cutting is important to keep things organized and prevent confusion. This way, you will know which variety you have when planting them in the garden.
Writing in pencil instead of ink pens or sharpies ensures the label lasts longer.
It is also a good idea to include the date you took the cutting on the label. This allows you to track the rooting process.
Step 6: Take the Dahlia Cutting
Look for a healthy stem with new shoots about 3-4 inches long and with at least two or, ideally, three sets of leaves. The stem should be strong and sturdy, not thin and spindly.
Using your sharp knife or scalpel, make a clean cut right at the base where the green growth meets the brown neck of the tuber. Then, remove the lower leaves.
Step 7: Dip in Rooting Gel
Put a small amount of rooting gel into a small shallow dish. Dip the base of the cutting into the gel. Make sure it covers the entire bottom section of the stem up to where the first set of leaves was.
Gently insert the cutting into the soil or the Root Riot Cube. Water the cutting thoroughly and place the humidity dome on the tray.
Check your dahlia cuttings daily. Humidity domes can cause excessive heat and moisture, leading to rotting.
Some dahlia growers avoid using the dome and successfully keep the trays moist and use a heat mat.
Step 8: Provide Light
For adequate feeder roots to develop, the cuttings will need a minimum of 14 hours of light per day.
You can use grow lights, a 40-watt fluorescent bulb, fluorescent shop lights, or an incandescent 100-watt bulb positioned about 3 to 4 feet above the cuttings.
Step 9: Transplant and Fertilize
After a couple of weeks, the dahlia cutting will have developed roots. You will then transplant the young plant to an individual pot and plant it at the same depth it grew in the starter pot.
After moving the cutting to a small pot, you can use fertilizer. I like using Grow Big, which contains bat guano, earthworm castings, and kelp.
After transplanting, there is no need to cover the pots with plastic domes. Keep the plants in a warm spot with bright light and ensure the soil stays evenly moist.
For the dahlia cuttings to begin producing tubers, they will need light for 12 hours or less daily.
Step 10: Harden Off and Plant in the Garden
After the last danger of frost in your area, you can begin hardening off your dahlia plants. This means gradually introducing them to natural sunlight and outdoor conditions.
Start by taking them outside for 30 minutes on the first day. Over the course of a week, increase the amount of time they are left outside.
Once the plants have adjusted to outdoor conditions and direct sunlight, it is time to plant them in the garden.
How to Care For Dahlia Cuttings
To help dahlia cuttings successfully root, three important things must be controlled.
- Humidity – cuttings will need to be in a humid environment until they have rooted. This keeps them from drying out but not too wet. The soil should be damp but not soaked, and if necessary, lightly misting the soil with a spray bottle can increase the humidity.
- Temperature – keep the temperature of the soil and the air around the cuttings between 65 and 75 degrees. To check the warmth of the soil, I use a soil thermometer.
- Light – dahlia cuttings need at least 14 hours of light per day to develop their roots. Once the plant has roots and is transplanted to a larger container, it will need 12 hours of light or less to develop tubers.
Frequently Asked Questions
How Many Cuttings Can You Take from a Tuber?
It is recommended not to take more than five cuttings to propagate new dahlia plants from a single tuber. Too many cuttings can exhaust the tuber’s energy reserve, leading to poor growth once the mother tuber is planted in the ground.
Best Rooting Medium for Cuttings
Dahlia growers use a variety of different mixes to start cuttings. A sterile rooting medium is the best option, and I have had great success with Root Riot Cubes.
Will Dahlia Cuttings Produce Tubers?
Once planted, dahlia cuttings will produce healthy tubers during the growing season. They can be harvested in the fall and stored for future planting the following year.
The number and size of tubers can vary depending on the variety of dahlia and growing conditions.
When Can You Take Dahlia Cuttings?
Spring is the best time to increase your dahlia stock by obtaining basal cuttings from tubers. Each tuber has the potential to yield approximately five new plants at no additional cost.
Will Dahlia Cuttings Flower in First Year?
Yes, dahlia rooted cuttings will flower in their first year.
Taking dahlia cuttings can be a great way to propagate new plants and expand your flower garden. Whether you are a seasoned gardener or a beginner, this method is effective for growing more of these beautiful flowers.