Dahlias are remarkably easy plants to grow once you get to know them. One of the best things about them is their love of life, these are some vigorous plants once they are growing in the heat of the summer. This vigour for life makes it particularly easy to multiply your plant numbers by taking cuttings.
Cuttings are exactly what they sound like, pieces of a plant cut off to grow on as a new plant. With dahlias, cuttings are taken from young new shoots that are grown on in damp compost. The cutting will product roots from the nodules where leaves grow and from tiny pieces of tuber that come with it within a matter or weeks, often within days.
You can actually take cuttings all summer from new shoots but the fastest way of rooting the cutting is by taking them directly from the plant’s tuber, the underground large energy storing roots. In spring, little buds will appear on the top of the tubers where shoots grow from.
If you plan to take cuttings from a plant, you can gently scrape back some of the soil or compost to expose the top of the tuber. Or if you’re planting the tuber in spring, leave the top slightly proud of the soil. You’ll soon see the buds burst into action and grow into new young shoots. When there is more than one shoot with at least 3 x sets of leaves and about 6 – 8cm long, you’re ready to take the cutting.
Dahlias are beloved for their gorgeous blooms that come in a stunning array of colors, shapes, and sizes. While buying tubers can get pricey, you can easily propagate more dahlias from cuttings. Taking cuttings allows you to bulk up your beds and share prized varieties with friends – all for free!
When to Take Dahlia Cuttings
The best time to take dahlia cuttings is in early spring, around March or April This gives the cuttings time to develop a good root system so they’ll thrive when planted out after the last spring frost
If you live in a warm climate where you can leave tubers in the ground over winter, you can take cuttings anytime once new growth appears in late winter or early spring.
For those who dig up and store tubers over winter, start them indoors 6-8 weeks before your last expected frost Pot the tubers in damp potting mix with the crown facing up Keep them in a sunny spot with temperatures around 65-75°F.
Once the sprouts reach 2-3 inches tall with 2-3 sets of leaves, they are ready for taking cuttings.
How to Take Dahlia Cuttings
Tools Needed
- Sharp, clean knife or snippers
- Small pots or trays
- Seed starting mix or potting soil
- Rooting hormone (optional)
- Clear plastic dome or bag
- Labels
Step 1: Sterilize your tools
Dip your cutting knife or snippers in a 10% bleach solution or isopropyl alcohol to sterilize between each cutting. This prevents the spread of disease.
Step 2: Cut a stem
Carefully cut a stem with 2-3 sets of leaves, just above where it attaches to the tuber. A clean cut is important to prevent rotting.
Step 3: Trim leaves
Remove the bottom set of leaves. Cut remaining leaves in half to reduce transpiration. This encourages energy to go towards root growth rather than leaf growth.
Step 4: Apply rooting hormone (optional)
Dip the end of the stem in rooting powder containing auxins or auxin precursors. This stimulates faster root development.
Step 5: Stick in potting mix
Poke a hole in damp potting mix with a pencil. Place the cutting in the hole and firm mix around it.
Step 6: Maintain humidity
Cover pots with a plastic dome or bag to retain moisture while roots develop. Remove condensation daily to prevent fungal issues.
Step 7: Provide light and warmth
Place cuttings in bright, indirect light and maintain temperatures of 65-75°F. Bottom heat mats help.
In 4-6 weeks, the cuttings should have well-developed roots and be ready to transplant. Harden off first, then plant out after all danger of frost is passed.
Tips for Success
- Take 2-3 cuttings per tuber for insurance in case some don’t take.
- Keep tools and pots sterile to prevent diseases like damping off.
- Don’t overwater – just keep potting mix moist, not wet.
- Provide at least 12 hours of bright, indirect light daily.
- Maintain warm temperatures around 70°F for optimal root growth.
- Gently tug cuttings after 3-4 weeks to check for root development before transplanting.
Troubleshooting Issues
Cuttings wilt: Increase humidity by misting more frequently. Ensure potting mix is moist but not wet.
Blackening stems: This is caused by damping off fungal disease. Sterilize tools and use new sterile potting mix.
No root growth: Check for adequate warmth and 12+ hours of bright light daily. Discard any cuttings that fail to root well.
Final Tips
Taking dahlia cuttings is an easy, inexpensive way to propagate your favorite varieties. In early spring, cut 2-3 inch stems and stick in sterile potting mix. Maintain warmth and humidity as the cuttings root. Then transplant the rooted cuttings to bulk up your dahlia collection. With proper care, you’ll have mounds of colorful blooms from your new plants!
Find the growing points at the top of the dahlia tuber and wait for it to grow 3 x sets of leaves
The cut bit of tuber on the main plant will dry and heal within a couple of days
Make More Dahlias How to take dahlia cuttings
FAQ
When should you take dahlia cuttings?
Dahlia cuttings are best taken in early spring, specifically when the dormant tubers have been potted up and started into growth in a warm environment, like a heated propagator. This typically occurs in late winter to early spring. You’ll want to select healthy, vigorous shoots and take basal or softwood cuttings.
Do dahlia cuttings root in water?
Yes, Dahlia cuttings can be rooted in water, though some growers find it less reliable than rooting in soil.
Can I root a broken dahlia stem?
Yes, broken dahlia stems can often be rooted to create new plants.
How many cuttings can you take from a dahlia?
You can get between 5 and I’ve heard people say as many as 20… Really, you can take as many as you want until the tuber craps out on you! Eventually the tuber will run out of energy to keep sending out shoots. It sometimes goes like this: the first cuttings are so big that they have hollow stems and will not root.
How to grow new Dahlias from basal cuttings?
Find out how to grow new dahlias from basal cuttings, in our practical guide. Bright, showy dahlias are a highlight of the late summer garden. You can increase your stock by taking basal cuttings from tubers in spring. Each tuber will give you around five new plants for free that will flower in summer.
Can you take Dahlia stem cuttings in late winter?
The good news is, you can get a real bang for your buck by taking dahlia stem cuttings in late winter. Taking cuttings from dahlias can net you five to 10 plants from a single tuber. Let’s learn more about growing dahlia cuttings so you can enjoy even more beautiful dahlia plants each year. Want to try your hand at rooting dahlia cuttings?
How do you propagate dahlias?
Even in you live in a more temperate climate, you can quickly and easily propagate your dahlias by cutting the tubers. Then, plant each tuber to fill your garden with these gorgeous blooms. Cut back the stalks 3-4 days before digging up your dahlias.