Gadenin日本語Get the appDivide, do not sow
Mugwort sets a huge quantity of wind-blown seed, and a plant you allow to flower in order to collect it will have scattered far more than you gathered. Since the plant divides readily and a division reaches picking size in a single season, there is no practical reason to raise it from seed.
Division also keeps the plant you already know. Aroma and leaf quality vary a good deal between individual plants, so once you have one with a scent you like, propagating it vegetatively is the only way to keep it.
Everything below is also a containment discipline. Any rhizome fragment you drop on open soil becomes a new plant, so work on a hard surface or over a tarpaulin.
Dividing an established clump
The best times are early spring as the first shoots appear and early autumn once the heat has gone. Both give the divisions weeks of root growing weather. Avoid dividing in the middle of summer, when the plant wilts before it can root.
- Turn the whole plant out Knock a potted plant out of its container, or lift a clump with a fork. Work on paving or a sheet so no fragments fall into open ground. Shake or wash enough compost off the roots to see the rhizomes clearly.
- Take the outside, discard the middle The vigorous growth is around the edge of the clump. Cut fist-sized pieces from the outer ring, each with three or four healthy shoots and a good length of white rhizome. The old woody center is the least productive part. Bin it.
- Cut the top back before potting Reduce the shoots on each division to about four inches (10 cm). A division with full-length top growth transpires faster than its damaged roots can supply and sulks for weeks.
- Pot each division on its own One division to a pot of at least three gallons (12 liters), in ordinary free-draining potting mix with no added feed. Water it in, keep it in bright shade for a week, then move it into full sun.
Stem cuttings
Useful when you want several plants from one clump without lifting it, or when you are given a shoot rather than a root. Take them from soft spring growth or from the flush that follows the early summer cut, never from a stem carrying flower buds.
| Step | Detail |
|---|---|
| Material | Non-flowering shoot tips four to five inches (10 to 12 cm) long |
| Preparation | Cut just below a node, strip the lower two thirds of leaves |
| Medium | Damp gritty potting mix or perlite, three cuttings to a small pot |
| Conditions | Bright shade, around 68F (20C), covered but ventilated daily |
| Rooting time | Two to three weeks. Resistance to a gentle tug means roots |
| Aftercare | Pot up individually, pinch the tip to make the plant branch |
Cuttings in water root readily but the roots are brittle and often fail on transplanting. Compost gives a sturdier plant.
Root cuttings, and a warning
Mugwort regenerates from short lengths of rhizome, which is exactly why it is so hard to eradicate and why root cuttings work so well. In late winter, cut two-inch (5 cm) lengths of firm white rhizome, lay them horizontally on damp compost, cover with half an inch (1 cm) of mix and keep them just moist. Shoots appear in three to five weeks.
The warning is the same fact seen from the other side. Every offcut you do not want is a viable plant. Never tip spare rhizome onto a compost pile, into a hedge bottom or over a fence. Dry it out completely on a hard surface first, or bag it and put it out with household waste.
Keeping track of what you made
Note the date of every division and how many pots came out of it. Mugwort divisions multiply quickly, and it is surprisingly easy to end up with more plants than you have safe places to stand them, which is how they end up given away or planted out in a hurry.
Record where each pot is standing, too. A division stood temporarily on soil while you find it a home is the most common way a rhizome escapes into the garden.