When to plant lemon balm in Detroit, Michigan
April 21 – May 5
Transplant outdoors · typical Detroit yearClimate basis: NOAA station Detroit City AP, MI (USW00014822), 6 mi (9 km) from downtown Detroit (ZCTA 48226 centroid), elevation 626 ft, on the 1991–2020 climate normals. Transplant lemon balm outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (April 21). One year in ten still freezes after May 6.
The Detroit year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 6
Every method, with its sources
Start seeds indoors
Mar 10 – Mar 24Wisconsin Horticulture sows lemon balm indoors about 4 to 6 weeks before the last spring frost, so the window runs 6 to 4 weeks before that date. Anchored to the median last spring freeze (Apr 21). University of Wisconsin-Madison Division of Extension, Wisconsin Horticulture · Virginia Cooperative Extension, Virginia Tech
Transplant outdoors
Apr 21 – May 5Wisconsin Horticulture ties lemon balm transplanting to seedling height rather than a date, so the frost anchor comes from Virginia Cooperative Extension's herb publication — whose herb table lists lemon balm — which sets all herb plants out after the danger of severe frost has passed. Anchored to the median last spring freeze (Apr 21). Virginia Cooperative Extension, Virginia Tech
Variety assumption: A hardy perennial that self-seeds freely; these windows apply to first-year plantings from seed or nursery plants.
These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.
Crop rule sources (2)
- University of Wisconsin-Madison Division of Extension, Wisconsin Horticulture: Lemon Balm, Melissa officinalis (accessed 2026-07-25)"Lemon balm can be started from seed sown indoors about 4 to 6 weeks before the last spring frost, although seeds may be somewhat slow to germinate."
- Virginia Cooperative Extension, Virginia Tech: Herb Culture and Use (Publication 426-420) (accessed 2026-07-25)"In addition, many culinary herbs, such as tarragon, can only be propagated asexually; seed-grown plants lack the oils that give them flavor."