Watermelon

Watermelon

Citrullus lanatus

Start watermelon indoors 1 week before your last spring frost, then plant out 2 weeks after your last spring frost. Space plants 36 in (91 cm) apart.

Photo: Forest and Kim Starr, CC BY 3.0 us · source

When to plant

Timed from your frost dates, so it holds wherever you garden. Give yours and every step below becomes a date.

See the dates for your garden

Enter your average last spring frost and first fall frost. Every timing on this site turns into a calendar date. Not sure of yours? Your local extension service or a search for “last frost date” and your town will tell you; the app finds them from your location.

Last spring frost
First fall frost

Saved in this browser only. Nothing is sent anywhere.

Optimal Indoor Start

From seedRecommended
  1. Start indoors1 week before your last spring frost
  2. Begin hardening off1 week after your last spring frost
  3. Plant out2 weeks after your last spring frost
  4. First harvestabout 80 days after sowing

Optimal Transplant

From seed
  1. Plant out2 weeks after your last spring frost
  2. First harvestabout 80 days after planting out

Optimal Direct Sow

From seed
  1. Sow outdoors2 weeks after your last spring frost
  2. First harvestabout 100 days after sowing

Growing watermelon

Spacing in the row
36 in (91 cm)
Between rows
72 in (183 cm)
Planting depth
1 inch
Sun
Full Sun
Soil
Well-drained, sandy loam, rich in organic matter, pH balanced
Germination
5-10 days at 75-90°F
Harvest season
Mid to Late Summer
Mature height
Vining, sprawling
Support
Trellis (optional for small fruits), None (ground sprawling)
Life cycle
Annual

Sow seeds 1 inch deep, 2-3 seeds per hill, thinning to strongest seedling.

Watering. Consistent moisture, especially during flowering and fruit set. Reduce as fruit ripens.

Neighbours

The companion chart →

Grows well beside

Keep apart from

Feeding

Seedlings
Diluted balanced liquid fertilizer after true leaves appear.
Growing
Balanced granular fertilizer or compost tea every 3-4 weeks.
Flowering and fruiting
High potassium fertilizer to support fruit set and development.
How often
Every 3-4 weeks during active growth.
Note
Avoid high nitrogen once flowering begins to prevent excessive vine growth at the expense of fruit.

Your watermelon, planned to the day.

Canopy turns these timings into dates from your own frost data, places every plant at its spacing on your garden map, and tracks it all the way to harvest.

Add watermelon to your planting calendar →

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