Arugula in Zone 4a & 4b
Eruca sativa
Yes, arugula grows in zones 4a and 4b. Plant it outside Apr 10–Apr 17.
When to plant arugula 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 | Apr 10–Apr 17 |
| Estimated harvest | May 20–May 27 (~40 days after direct-sowing) |
Spacing: 9 per square foot (square-foot-gardening spacing). Mature height: 0.5-1.5 ft.
Plant alongside it in zone 4b
These go outside within two weeks of arugula in zone 4b, so one planting day can cover them.
- OnionApr 24–May 1
- RadishApr 17–Apr 24
- PeaApr 3–Apr 10
- SpinachApr 17–Apr 24
- BeetApr 24–May 1
- Broccoli Rabe (Raab)Apr 24–May 1
Arugula is about as fast as salad greens get, direct-sown and ready to harvest in around 40 days, with a peppery bite that gets sharper as the weather warms.
How arugula fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Arugula needs about 40 days from sowing to first harvest.
Arugula 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 |
|---|---|---|---|
| 2a & 2b | Not usually | Apr 15–Apr 22 | May 25–Jun 1 |
| 3a & 3b | Not usually | Apr 25–May 2 | Jun 4–Jun 11 |
| 4a & 4b (your zone) | Not usually | Apr 10–Apr 17 | May 20–May 27 |
| 5a & 5b | Not usually | Apr 5–Apr 12 | May 15–May 22 |
| 6a & 6b | Not usually | Mar 21–Mar 28 | Apr 30–May 7 |
| 7a & 7b | Not usually | Mar 6–Mar 13 | Apr 15–Apr 22 |
| 8a & 8b | Not usually | Feb 18–Feb 25 | Mar 30–Apr 6 |
| 9a & 9b | Not usually | Jan 11–Jan 18 | Feb 20–Feb 27 |
| 10a & 10b | Not usually | Dec 26–Jan 2 | Feb 4–Feb 11 |
| 11a & 11bFall window | Not usually | Oct–Mar | ~40 days after direct-sowing |
Harvest dates are about 40 days after the sow or plant-out date.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
Good companions
- Carrot: Fast-maturing, non-competing salad-garden interplant.
- Lettuce: Similar light/water needs; grown together as cut-and-come-again greens.
Where to buy arugula seeds
Botanical Interests · True Leaf Market · Burpee · High Mowing Organic Seeds (each supplier's arugula seeds)
Varieties we recommend, and where to get them:
- Sylvetta: Cornell's Vegetable Varieties for Gardeners database describes Sylvetta (a different, wild species) as small-leaved, slow-growing, and slow to bolt, a good option if standard arugula bolts on you too fast in a warm spring. Buy: High Mowing Organic Seeds Full notes
- Astro: A wider, less-lobed leaf than standard arugula with a milder flavor while young and cool, slower to bolt, and heat tolerant once it does warm up. Buy: Botanical Interests · True Leaf Market · High Mowing Organic Seeds Full notes
- Roquette: The standard, fast-growing salad type most seed racks sell as plain 'arugula', with dark green, wide, tongue-shaped leaves. Buy: True Leaf Market Full notes
See why we recommend these suppliers →
As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a clear consensus of positive, independent reviews, or ones we bought and use ourselves. Each item on our gear page says which.
See it growing
Search YouTube for "growing arugula" 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 →
Pin this for later
Growing Arugula in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
Save to Pinterest