When to plant arugula in Grand Rapids, Michigan
August 27 – September 10
Fall planting · typical Grand Rapids yearClimate basis: NOAA station E Grand Rapids, MI (USC00202375), 3 mi (5 km) from downtown Grand Rapids (ZCTA 49503 centroid), elevation 746 ft, on the 1991–2020 climate normals. Plant arugula for fall from approximately the dates above, anchored to the median first fall 32°F freeze (October 10). One year in ten still freezes after May 23.
The Grand Rapids year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 23
Every method, with its sources
Fall planting
Aug 27 – Sep 10Cornell Garden-Based Learning caps successive arugula sowings at "about a month before your average first frost date", so the fall sowing window is the 14 days ending at that cutoff (first fall frost minus 44 to minus 30 days); Wisconsin Horticulture agrees arugula tolerates frost but gives no numeric offset. Anchored to the median first fall freeze (Oct 10). Cornell University Garden-Based Learning (Cornell Cooperative Extension)
Start seeds indoors
Not calculatedThe cited extension guides do not time an indoor seed-starting window for this crop.
Transplant outdoors
Not calculatedThe cited extension guides do not time an outdoor transplanting window for this crop.
Direct-sow outdoors
Not calculatedCornell times spring arugula only by soil condition — "Plant as soon as soil can be worked in spring." — which is not an offset from a freeze date, so no spring window is computed here. The window above is the last succession sowing before the first fall freeze.
Variety assumption: No spring window is published: every extension page fetched gives only soil-workability language ("as soon as soil can be worked") or the unquantified "several weeks before the last frost", neither of which yields an honest numeric offset, so only the frost-anchored fall cutoff is encoded.
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 (1)
- Cornell University Garden-Based Learning (Cornell Cooperative Extension): Arugula growing guide (accessed 2026-07-25)"Make new plantings every 2 to 3 weeks for a continuous supply until about a month before your average first frost date."