Taking cuttings is a great way to increase your dahlia supply, and the best way to make more cuttings is to use the leaf cutting technique. This technique was introduced to me through several Dahlia Facebook Groups via this YouTube video.
I do find leaf cuttings to be more challenging than the more common method of taking cuttings. However, you can effectively get double the cuttings by doing leaf cuttings.
Some strong winds sadly tore a branch off one of my Mom’s Special dinnerplate dahlia plants that I was hoping to get blooms from soon. To salvage something positive from this damage, I took leaf cuttings from this branch. You can follow this guide to learn how to take your own dahlia leaf cuttings:
-Skip the supplies and basic dalia cutting tips and go straight to the leaf cutting tutorial-
Supplies list
- Rapid Rooter plugs (buy here)
- Dauber to enlarger plug hole
- Scalpel or sharp small scissors
- Cutting board
- Bowl of water
- Peppermint Castille soap (buy here)
- Avis Spidermite Treatment
- Plant abel and pencil
- Copper Fungicide
- Rooting hormone (optional, I don’t use it)
- Something to house the cutting(s) like a cell tray or plastic cup
- A way to cover the cutting (dome, lid, plastic bag) to keep air around cutting humid
- Lights on a timer
- Shelf to keep your cuttings
- Water mister bottle
Important general notes about growing dahlias from cuttings
After many, many, many, many failures taking cuttings... Many failures. Like, failing for several years to get dahlia cuttings to root and then keep rooted cuttings alive, I have found the following to be very important. (As always, everything I write about in regards to gardening is through the lens of living in humid, hot-ass Florida and may not exactly apply to your climate and growing zone.)
Keep your cuttings indoors
I am not a big fan of plants inside, so I was always trying to start my seeds and grow my cuttings outside with various levels of success with seed starting and basically no success with cuttings. I’d only get maybe 1 out of 20 cuttings to make it. Didn’t matter the time of year, or where I placed my cuttings, they would die. Things dramatically changed for the better when I moved the operation inside.
Find a place indoors to grow your cuttings. I use inexpensive plastic shelves from the big box hardware store in an extra room earmarked specifically for seed starting and cuttings. But a small corner of your home will work just fine. You can sit a small shelf inside a plastic tote to keep mess and water from damaging your indoor surfaces and wrap a cheap plastic shower curtain around the back and sides of the shelf to keep any mess contained.
Manage the temperature
I have a small space heater setup in the room where I grow my cuttings, it turns on if the temp drops, so the area my cuttings are being care for stays between 70-75 degrees
You do not need a heat mat, and many find heat mats damage their cuttings. You just want the ambient air temperature to be between 70-75 degrees.
Use Rapid Rooter Plugs (or something similar)
I have tried wet vermiculite, water only, perlite, bagged potting mix and my own soil mix all which ended primarily in rotted cuttings. Nothing is as successful as spending the money on rapid rooter plugs. Don’t let all the time and effort you invest in taking and starting cuttings be wasted, use the rapid rooter plugs (link to product) to achieve the best percentage of cuttings that successfully root.
Proactively treat for spider mites and fungus on a regular basis
Dahlia cuttings are extremely prone to spider mites and fungus. Assume you will have to deal with both and proactively treat for them on a regular basis so you don’t lose your dahlia cuttings.
Shopping: You can get spider mite treatment concentrate here and find Copper fungicide spray here to treat for fungus (link to product)
Setup grow lights and put them on a timer
Whether you just want to grow just a few cuttings or you want to build a massive army of cloned dahlia plants there are lighting setups for any scale of plant propagation (and they really aren’t that expensive). Having lights on your cuttings will drastically increase your success rate. You can even leave the lights on 24/7 but typically 14-16 hours a day will suffice.
Shopping: small light setup (link to product) and link to larger grow light setup (link to product)
Shopping: timer (link to product)
Check them every couple of days
Whether looking for signs of rot, drying out or just spritzing them to keep the cuttings in a humid environment, cuttings are not a “set it and forget it” undertaking. You will need to keep them moist, check on them for signs of rooting and rot, and treat them for spider mites and fungus.
The Process of Dahlia Leaf Cuttings with Pictures
My severed Mom’s Special branch was pretty woody at the bottom and mostly hollow. Typically not the best candidate for taking cuttings. But with the Leaf Cutting method I was able to get about 10 cuttings.
Step 1) Prepare all the crap you need for your cuttings, soak your plugs
See above supplies list, and get setup on a table. I also like to have paper towels handy as water puddles can get on the table top as you work. I squirt some peppermint castile soap into my bowl of water to treat the plugs and cuttings for pests. Then I plop my rapid rooter plugs into the water to soak while I do everything else. I arrange all the other supplies around me and go ahead and label some plant markers with a pencil with the variety name and date of the cutting
Step 2) Identify where you’re going to cut your stem and cut your leaf pair segments
To take the leaf cuttings you need to cut your stem into segments first, above and below where your leaf pairs attach to the stem. See pictures below:
Step 3) Cut down the middle of the stem for each of your leaf pair segments
Each segment will make two cuttings. Take your scalpel and cut right down the stem.
If you don’t have the leaf node, where the leaf meets the stem, it will not root and will not make a new dahlia plant. The little part circled in the photo below is where new stems will grow. This is where your dahlia plant would have sent out lateral growth. Make sure not to disturb this on your cutting.
Step 4) Trim up the leaves of each cutting
You don’t need all of the leaves, you can cut the leaves down (see picture). Your cutting will grow from the stem inside the root riot plug
Step 5) Give your cutting a bath
I like to dunk the cutting into the bowl of water with the peppermint castile soap.
Step 6) Use the fat end of the dauber to open up the hole in a rapid rooter plug
The hole it comes with is too small to house the stem. Push the dauber into the hole to widen it (see picture)
Step 7) Push the stem into the hole (carefully)
Push the stem of your cutting into the hole, without breaking it.
OPTIONAL: Before pushing the stem into the plug, you can also opt to dip it in rooting hormone gel or powder. I haven’t been using rooting hormone at all and I have hundreds of cuttings going at the moment. You can risk burning your cutting with rooting hormone, but you should see stronger roots and faster rooting when you use rooting hormone. BUT YOU DO NOT NEED rooting hormone to be successful.
Step 8) House your new cutting in something with a humidity dome
I like to put them either inside a plastic shot glass and then inside a domed container with air holes, or into a cell tray with a dome with air holes.
If you don’t have a cell tray, you can put the cutting in a little plastic shot glass, inside a bigger plastic cup with a ziplock baggie loosely overtop of the bigger cup as a humidity dome.
You want to keep your cutting covered in something clear that breathes. This will keep your cutting from drying out but not so wet that it will rot.
Make sure to label each cutting variety so you don’t forget which cutting is which dahlia variety. Pencil is best on plant labels.
Step 9) Every few days re-dunk your cutting in water and spray for fungus and spider mites
I like to make up a fresh bowl of water and peppermint castille soap and every few days dunk each cutting, rapid rooted plug and all, into the water. I hold the cutting underwater until the bubbles stop to rehydrate the plug and then put the cutting back in the cell of the tray or back in the shot glass. This is a great time to check for roots. I also spray for spider mites and fungus. This is a bit time consuming depending on how many cuttings you have going but this has worked well for my success rate.
Step 10) Pot up once it’s rooted and remove the humidity dome
When you’re growing from leaf cuttings, it can take longer for them to root then typical cuttings. Your new leaf growth and roots will come from the part you pushed into the rapid rooter plug. Your original leaves will likely die back. You can cut those off once your cutting has grown new leaves and pushed out roots.
Anywhere from 10-30 days you should have a rooted cutting. Once you see healthy roots appear, you can pot your cutting up into a 3-4” pot in potting mix and remove the humidity dome. Keep your baby dahlia plant under lights and keep misting it with water and treating for fungus and spider mites until you’re ready to plant your dahlia clone out.
If it’s the right time of year, you can also plant your cutting directly outdoors in your prepared growing bed once it’s rooted. I have planted rooted cuttings directly outside with great success in early April. I would imagine the height of summer is too hot to put a baby cutting outside, at least where I am in hot, humid Florida.
Benefits of Growing Dahlias from Cuttings
Taking, preparing and growing on dahlia cuttings is quite a bit of work. So why bother with all this rigmarole in the first place when you can just grow dahlias from tubers?
There are several benefits of growing dahlia cuttings:
- You can quickly increase your dahlia inventory
- You can take many, many cuttings from one dahlia plant to rapidly increase your dahlia inventory. You cutting will grow and product flowers in its first year and should produce tubers as well
- You can get a head start on the growing season and produce flowers before your tubers
- By taking and maintaining your dahlia cuttings, you can have dahlia plants ready to plant at the very beginning of your growing season to get a head start on flower production. We have had dahlia cuttings that were planted AFTER our tubers had already started sprouting that made flowers before the tuber-started dahlias.
- Protect against tuber rot
- With all the rain we get in Florida, we lose a good number of tubers to rot, despite our best efforts to plant in well-draining soil. Rooted cuttings are much less likely to rot than tubers that are waking up
- Guard against poor tuber production/storage
- Some dahlia varieties just don’t make great tubers. And sometimes despite our best efforts, tubers rot in storage. By maintaining cuttings of your most prized varieties you can have a very effective back-up system to your tuber collection.