Swiss Chard in Zone 3a & 3b
Beta vulgaris
Yes, Swiss chard grows in zones 3a and 3b. Start seeds indoors May 2–May 9 and plant out May 16–May 23.
When to plant Swiss chard in zone 3b
Zones 3a and 3b share the same average frost dates, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Either works.
| Start indoors | May 2–May 9 |
|---|---|
| Direct sow / transplant outside | May 16–May 23 |
| Estimated harvest | Jul 10–Jul 17 (~55 days after planting) |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1-2 ft.
Plant alongside it in zone 3b
These go outside within two weeks of Swiss chard in zone 3b, so one planting day can cover them.
- OnionMay 9–May 16
- RadishMay 2–May 9
- CarrotMay 9–May 16
- CabbageMay 16–May 23
- LettuceMay 16–May 23
- BroccoliMay 16–May 23
Swiss chard does what spinach and lettuce can't: keep producing through the heat of summer without bolting. It can be started indoors or direct-seeded, and a single planting will often keep giving cut-and-come-again harvests for months.
How Swiss chard fits zone 3's season
Zone 3b's frost-free window runs about 98 days, from May 30 to September 5. Swiss chard needs about 55 days from sowing to first harvest.
Swiss Chard planting windows in every zone
Zone 3b 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 (your zone) | May 2–May 9 | May 16–May 23 | Jul 10–Jul 17 |
| 4a & 4bSpring window | Apr 17–Apr 24 | May 1–May 8 | Jun 25–Jul 2 |
| Fall window | Not usually | Jul 13–Jul 27 | Sep 6–Sep 20 |
| 5a & 5bSpring window | Apr 12–Apr 19 | Apr 26–May 3 | Jun 20–Jun 27 |
| Fall window | Not usually | Jul 28–Aug 11 | Sep 21–Oct 5 |
| 6a & 6bSpring window | Mar 28–Apr 4 | Apr 11–Apr 18 | Jun 5–Jun 12 |
| Fall window | Not usually | Aug 7–Aug 21 | Oct 1–Oct 15 |
| 7a & 7bSpring window | Mar 13–Mar 20 | Mar 27–Apr 3 | May 21–May 28 |
| Fall window | Not usually | Aug 17–Aug 31 | Oct 11–Oct 25 |
| 8a & 8bSpring window | Feb 25–Mar 4 | Mar 11–Mar 18 | May 5–May 12 |
| Fall window | Not usually | Sep 2–Sep 16 | Oct 27–Nov 10 |
| 9a & 9bSpring window | Jan 18–Jan 25 | Feb 1–Feb 8 | Mar 28–Apr 4 |
| Fall window | Not usually | Sep 27–Oct 11 | Nov 21–Dec 5 |
| 10a & 10bFall window | Aug–Jan | Sep–Feb | ~55 days after transplanting |
Harvest dates are about 55 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
- Bush Beans: Beans fix nitrogen chard uses heavily.
Where to buy Swiss chard seeds
Botanical Interests · Burpee (each supplier's Swiss chard seeds)
Varieties we recommend, and where to get them:
- Bright Lights: The gold-standard rainbow chard, an AAS winner at 55 days with savoyed leaves and stems in gold, pink, orange, red and white on the same planting. Buy: True Leaf Market · Burpee Full notes
- Fordhook Giant: The traditional white-stemmed, green-leaf standard Johnny's rates as a strong, heat-tolerant performer at about 50 days. Buy: Botanical Interests · True Leaf Market · Burpee · High Mowing Organic Seeds Full notes
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing Swiss chard" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 3b calendar · Plan your beds in the Garden Designer →
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Growing Swiss Chard in USDA zone 3b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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