Mugwort in Zone 4a & 4b
Artemisia vulgaris
Yes, mugwort grows in zones 4a and 4b and comes back each year. Plant it outside May 15–May 22.
When to plant mugwort in zone 4b
Zones 4a and 4b share the same average frost dates, so this page covers both.
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | May 15–May 22 |
| Estimated harvest | First real harvest the season after planting |
Spacing: about 4 square feet per plant (square-foot-gardening spacing). Mature height: 2-4 ft.
Before you plant: Mugwort has a winter-hardiness note for zone 4b. See the details below.
Plant alongside it in zone 4b
These go outside within two weeks of mugwort in zone 4b, so one planting day can cover them.
- BasilMay 29–Jun 5
- BorageMay 15–May 22
- DillMay 8–May 15
- RosemaryMay 29–Jun 5
- American GinsengMay 15–May 22
- AniseMay 15–May 22
Mugwort has a long history in cooking and herbal medicine, and it is one of the more difficult plants to have in a garden.
How mugwort fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Mugwort takes about 1 growing season to reach first worthwhile harvest, so what matters here is how many of these seasons it gets, not whether one is long enough.
Mugwort is hardy in zones 3-8, so in zone 4b it stays in the ground through winter and comes back rather than being replanted. Allow about 4 ft of spread at maturity.
Mugwort planting windows in every zone
Zone 4b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 3a & 3b | Not usually | May 30–Jun 6 | First real harvest the season after planting |
| 4a & 4b (your zone) | Not usually | May 15–May 22 | First real harvest the season after planting |
| 5a & 5b | Not usually | May 10–May 17 | First real harvest the season after planting |
| 6a & 6b | Not usually | Apr 25–May 2 | First real harvest the season after planting |
| 7a & 7b | Not usually | Apr 10–Apr 17 | First real harvest the season after planting |
| 8a & 8b | Not usually | Mar 25–Apr 1 | First real harvest the season after planting |
Good companions
No well-established companions for mugwort.
Where to buy mugwort seeds
True Leaf Market (each supplier's mugwort seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing mugwort" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 4b calendar · Plan your beds in the Garden Designer →
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Growing Mugwort in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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