Gadenin日本語Get the appThe year at a glance
Mugwort dies back to the crown over winter and shoots again in spring. Almost nothing needs doing for most of the year, but two or three jobs are time critical, and missing the late summer one is what turns a garden plant into a garden problem.
| Season | What the plant does | Jobs |
|---|---|---|
| Early spring | Shoots come up from the crown and rhizomes | Divide and repot, check the pot base for escaped roots |
| Mid to late spring | Soft silver-backed leaves, stems still short | The main picking window. Take shoot tips heavily |
| Early summer | Stems elongate, lower leaves coarsen | Cut the whole clump to a third of its height |
| Midsummer | Flush of tender basal regrowth | Second harvest. Watch for the first flower buds |
| Late summer | Tall stems set greenish buds | Cut and bag every flowering stem before buds open |
| Autumn | Growth slows, rhizomes fatten | Second window for division. Last light picking |
| Winter | Top growth dies back | Clear dead stems, keep the pot on the dry side |
Spring: the only good picking window
As soon as shoots reach about six inches (15 cm) the leaves are at their best, soft and strongly aromatic with a silver reverse. That lasts four to six weeks, until the stems start to run up, and after that the leaves coarsen and turn bitter. Pick generously while it lasts rather than saving it.
Spring is also when a container gets checked. Lift the pot, look underneath for roots through the drainage holes, and walk the ground around it for any shoot that has appeared where it should not be.
Early summer: the cut that resets the plant
When the stems have elongated and the leaves are no longer worth taking, cut the whole clump back to about a third of its height. Within two to three weeks it throws a flush of soft new shoots from the base, which gives you a second harvest of tender leaves.
The cut also pushes flowering later, which shortens the period in which you have to police seed. On a vigorous plant, cutting a second time a few weeks afterwards is worth doing for both reasons.
Late summer: the job that cannot be skipped
Tall stems appear carrying dense heads of small greenish buds. They are inconspicuous, which is the danger. Once open, they release pollen that is a major late-season hay fever allergen, and within a few weeks they shed enormous quantities of dust-fine seed that the wind takes across the whole neighborhood.
Go over the plant weekly from the moment the first buds show and cut every flowering stem down to the base. Bag them and put them out with household waste. Do not compost them and do not leave them lying, because cut stems will finish ripening their seed on the ground.
If you find that stems have already shed, cut them anyway and expect seedlings next spring nearby. Pull those while they are small, when a single root comes up cleanly.
Autumn and winter
Autumn is the second good window for dividing and repotting, once the heat has gone but with weeks of root growing weather left. The last light picking of soft regrowth also comes now, before the first frosts blacken the top.
After dieback, clear the dead stems away so rust and mildew do not overwinter in them, and stand the pot where it will not sit in water. Mugwort is hardy well below freezing and needs no protection, but a waterlogged pot rots the crown.
The dates worth writing down
Four records make the following year straightforward: the day the first shoots appear, the day the stems begin to elongate, the day you cut the clump back, and the day you see the first flower buds. Those four fix your whole calendar to your own site rather than to a general rule.
Add a note of anywhere a shoot or a seedling turned up outside the pot, with the date and the position. A repeat in the same place next year means an established rhizome and needs digging rather than pulling.