Watercress in Zone 8a & 8b
Nasturtium officinale
Yes, watercress grows in zones 8a and 8b. Start seeds indoors Mar 4–Mar 11 and plant out Mar 11–Mar 18.
When to plant watercress in zone 8b
Zones 8a and 8b 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 | Mar 4–Mar 11 |
|---|---|
| Direct sow / transplant outside | Mar 11–Mar 18 |
| Estimated harvest | Apr 30–May 7 (~50 days after planting) |
Spacing: 9 per square foot (square-foot-gardening spacing). Mature height: 4-10 in.
Plant alongside it in zone 8b
These go outside within two weeks of watercress in zone 8b, so one planting day can cover them.
- OnionMar 4–Mar 11
- RadishFeb 25–Mar 4
- CarrotMar 4–Mar 11
- CabbageMar 11–Mar 18
- LettuceMar 11–Mar 18
- BroccoliMar 11–Mar 18
Watercress is the plant upland cress is compared against and named for, a peppery salad green that shares its flavor but is harder to grow, since it needs constantly saturated soil rather than an ordinary garden bed.
How watercress fits zone 8's season
Zone 8b's frost-free window runs about 230 days, from March 25 to November 10. Watercress needs about 50 days from sowing to first harvest.
Watercress planting windows in every zone
Zone 8b 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 | May 9–May 16 | May 16–May 23 | Jul 5–Jul 12 |
| 4a & 4b | Apr 24–May 1 | May 1–May 8 | Jun 20–Jun 27 |
| 5a & 5b | Apr 19–Apr 26 | Apr 26–May 3 | Jun 15–Jun 22 |
| 6a & 6b | Apr 4–Apr 11 | Apr 11–Apr 18 | May 31–Jun 7 |
| 7a & 7b | Mar 20–Mar 27 | Mar 27–Apr 3 | May 16–May 23 |
| 8a & 8b (your zone) | Mar 4–Mar 11 | Mar 11–Mar 18 | Apr 30–May 7 |
| 9a & 9b | Jan 25–Feb 1 | Feb 1–Feb 8 | Mar 23–Mar 30 |
| 10a & 10b | Jan 9–Jan 16 | Jan 16–Jan 23 | Mar 7–Mar 14 |
Harvest dates are about 50 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
No well-established companions for watercress.
Where to buy watercress seeds
Botanical Interests (each supplier's watercress seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing watercress" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 8b calendar · Plan your beds in the Garden Designer →
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Growing Watercress in USDA zone 8b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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