Watermelon in Zone 9a & 9b
Citrullus lanatus
When to plant watermelon in zone 9b
Zones 9a and 9b share the same average frost dates in our data, so this page covers both.
Method: Direct sow: Direct-sow outside. Watermelon doesn't transplant well, or doesn't need the extra time indoors.
| Start indoors | Not typically started indoors |
|---|---|
| Direct sow / transplant outside | Mar 1–Mar 8 |
| Estimated harvest | May 25–Jun 1 (~85 days after direct-sowing) |
Spacing: about 10 square feet per plant (square-foot-gardening spacing). Mature height: 6-10 in.
Watermelon asks for more room and more patience than almost anything else in a vegetable garden, at just 0.1 plants per square foot, a single vine can sprawl across a large share of a bed, and it takes most of a summer to deliver fruit.
How watermelon fits zone 9's season
Zone 9b's frost-free window runs about 293 days, from February 15 to December 5. Watermelon needs about 85 days from sowing to first harvest.
Good companions
- Sweet Corn: Corn provides light afternoon shade without heavy competition for space.
Where to buy watermelon seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing watermelon" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 9b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
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Growing Watermelon in USDA zone 9b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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