The fastest start
Growing Mint from Cuttings for Kratky
A mint cutting is the quickest, cheapest way to start a Kratky mint container. One healthy stem roots in a glass of water in a week or two and is ready for a net pot soon after.
Why cuttings
Why Start Mint from a Cutting?
Mint roots from a stem more easily than almost any other herb. A cutting is also an exact copy of its parent, so a peppermint cutting gives you true peppermint, which seed often does not. And it skips the slow seedling stage: a rooted cutting is already a small plant.
Cuttings also arrive clean. A nursery plant brings soil, and soil in a Kratky container feeds algae and root rot. A stem rooted in plain water starts with white, clean roots that go straight into the net pot. For which mint to choose, see mint varieties for Kratky.
4-6"cutting length
Step by step
How to Root a Mint Cutting
From one stem to a plant in a Kratky container.
Cut a healthy stem
Choose a green, non-flowering stem and cut 4 to 6 inches from the tip, just below a leaf node (the point where leaves join the stem).
Strip the lower leaves
Remove the leaves from the bottom 2 inches so no leaves sit under water. Keep the top few pairs.
Root it in water
Stand the stem in a glass of plain water in bright, indirect light. Change the water every few days. White roots usually appear within 7 to 14 days.
Move it to a net pot
When the roots are 1 to 2 inches long, set the cutting in a net pot with clay pebbles or a rockwool cube, roots pointing down through the holes.
Start the Kratky container
Fill a dark container with nutrient solution so the base of the net pot just touches it. From here, let the level fall as the plant drinks.
After planting
The First Weeks in the Container
For the first week the cutting may wilt a little while its water roots adjust to nutrient solution. Keep it out of hot, direct sun for those few days. Once new leaves appear at the tip, it has settled and can take full light: 6 to 8 hours of direct window sun, or 12 to 16 hours under a grow light.
Don't top the container up to the brim as the level drops. The air gap that forms is what gives the upper roots oxygen. If the solution runs low before the plant is mature, add fresh solution part way only, so the upper roots stay in the air.
Start cutting leaves once the plant is 4 to 6 inches tall and has several new pairs of leaves, usually three to five weeks after planting. Regular cutting is what keeps mint bushy, as the main Kratky mint guide explains.
3-5weeks to harvest
Troubleshooting
When a Cutting Doesn't Root
- Stem turns black or slimy: the water got warm or stale. Cut above the dark part, use fresh water and change it more often.
- Leaves wilt and don't recover: too many leaves for no roots. Pinch off all but the top two pairs.
- No roots after three weeks: the stem was woody or flowering. Take a softer, younger tip.
- Roots but no new growth: not enough light. Move it to a brighter window or under a grow light.
More plants
Taking Several Cuttings at Once
One healthy mint plant can give you a dozen cuttings. Root a few more than you need: not every stem roots at the same speed, and you can keep the strongest. Spares make good backups, too. A rooted cutting sitting in a glass of water on the sill is a fresh start waiting for the day your main container gets crowded.
Take cuttings from different stems around the plant rather than stripping one side, so the parent stays balanced and keeps producing. Cut in the morning, when the stems are full of water, and get them into water straight away. If you are rooting several varieties at once, label each glass.
FAQ
Mint Cutting Questions
Can I root mint from grocery store sprigs?
Often, yes, if the stems are fresh and firm. Pick the greenest sprigs, trim the ends and follow the same steps.
Do I need rooting hormone?
No. Mint roots readily in plain water.
Can I put the cutting straight into the Kratky container?
You can, but rooting it in water first lets you see that roots have formed before you commit a container to it.
How many cuttings per container?
One per net pot. A large container can hold two or three net pots of the same mint.
When should I take cuttings?
Any time the parent plant is growing actively. Indoors under lights, that is year-round.
Related Mint Guides
Not sure which mint to start? Compare the varieties, or plan ahead for mint's big roots.