Gadenin日本語Get the appWhy cuttings rather than seed
Mints cross readily, so a seedling rarely smells like its parent. If you have a plant whose scent you like, seed is the one method guaranteed to lose it.
A cutting or a division is genetically the same plant, so the aroma carries across unchanged. That is why mint is almost always sold as plants rather than seed.
Rooting in water
Cut a shoot about four inches (10 cm) long below a node, strip the lower leaves so no leaf sits in the water, and stand it in a glass in a bright spot out of direct sun. Change the water every couple of days.
Roots appear within one to two weeks in warm weather. Pot up once they are an inch or two long, into ordinary compost.
Do not let the compost dry out in the week after potting. That is when the new roots are most vulnerable, and losing them means starting again.
Rooting straight into compost
The same cutting pushed into damp compost roots just as well and skips the transition from water roots to soil roots. Keep it out of direct sun and just damp rather than wet.
You cannot see progress, so judge by whether the cutting is still firm and whether new growth appears at the tip after two or three weeks.
Dividing a clump
Division is the fastest way to get a full sized plant. Lift the clump in spring or autumn, pull or cut it into pieces each with roots and a few shoots, and replant the vigorous outer sections.
Throw the old center away. On a clump more than two years old the middle is woody and produces small leaves, and keeping it is what makes people think their mint has deteriorated.
Decide where the surplus goes
Mint propagates so easily that the real problem is what to do with the results. Decide before you start: how many plants you actually want, who is getting the rest, and that whatever is left goes in the bin rather than on the compost pile or in a corner of the garden.
Repotting and telling when it is pot bound
A mint in a pot needs dividing or repotting roughly every year. The signs are consistent enough to read directly.
| What you see | What is happening | What to do |
|---|---|---|
| Water runs straight through | Roots have displaced the compost | Move up a size, or divide and replant |
| Small, pale leaves | Pot bound and short of nutrients | Repot into fresh compost in spring or autumn |
| Bare and dying in the middle | The center of the clump is old | Keep the outside, discard the middle, replant |
| Roots out of the drainage holes | Escaping downwards | Lift the pot and bring the repotting forward |
| The compost repels water | The rootball has set hard | Stand the pot in water to rewet it, and repot at the next opportunity |
Repot in spring or autumn. Lifted in high summer or in winter, the roots do not move and the plant loses a whole season recovering.
When cuttings do not root
The usual causes are a cutting taken without a node, water left to go stale, a room too cold, or a cutting left with too many large leaves so it dried out. All four are easy to correct on the next attempt.
If the cut end has gone black and soft, the water was stale. Wash the glass, recut above the damage and change the water daily, and a cutting from the same stem will root.