Some growers take time in the fall to take cuttings from Dahlia plants before the first frost. When rooted and properly cared for, these cuttings can turn into next years plants, ensuring that you will have your favorite variety even if the tubers do not survive.
Taking cuttings is easy, overwintering them can be a challenge. I want to help you to be as successful as possible with the following steps.
Taking Cuttings
Step 1:
Start by making sure that you are taking cuttings from healthy plants. Look for lateral shoots that have at least two sets of leaves.
The photo above shows a large stem with a lateral stem growing. The leaves look green and healthy, and I will be able to remove multiple sets of leaves.
I gently remove with my hands, but you can also use pruners, just make sure that your tools are sterilized.
Step 2.
Remove leaves, and ensure that the stem is not hollow
The image above shows an exposed node where the leaf was removed.
Dahlias have hollow stems, but the portion of the stem below the node should not be hollow. If it is, you need to cut closer to the nodes. A hollow stem will cause rot before the cutting can produce roots.
Above is an example of a hollow stem.
Step 3:
Place your cutting in the medium of your choice. You'll want to ensure it's a sterile medium to prevent rot. Sometimes I even leave mine in water for a few days.
You may choose to use a rooting hormone, your results may vary with this. I haven't noticed any improvement in rooting success.
Common options for rooting mediums:
Water
Soil
Sand
Oasis Root Cubes - These are my personal favorites
Step 4:
If the leaves are too large, you may want to cut them in half to control leaf transpiration- this is when the leaves produce moisture which can potentially cause rot.
Humidity- Cuttings need humidity to root, I use these greenhouse trays with a humidity dome.
Temperature - 65-75 degrees
Lights - Cuttings require at least 14 hours a day to root. A fluorescent 40-watt bulb, or incandescent 100-watt bulb, 4 to 5 feet above the cutting bed is sufficient for forming roots.
Fertilizer - I add water from my friends fish tank weekly. I don't know the science behind this method, but I've had great success with it!
You can also fertilize with Jack's 20-20-20 or the professional Plantex 20-20-20 once rooted
I've also had success misting my plants with Clonex spray if they are starting to look sad or yellow. I mist these at night when the lights are off.
Step 5:
Check your cuttings regularly, they should root in 10-20 days. Remove any cuttings that show sign of wilt or rot.
Keep your medium moist, don't let your cuttings dry out.
Watch for powdery mildew- you can use hydrogen peroxide to eliminate this.
If your plant gets too large, you can always take cuttings from the top of your plant to increase your quantity of plants.
Keep your cuttings indoors until danger of frost has passed, then plant outside as normal.
Good luck!
**This post contains affiliate links which means I may make a commission on purchases at no cost to you. Everything I've linked is an item I've personally tried and will vouch for**