Planting timing · Frost-anchored
When to plant watermelon
Plant watermelon after frost on the cited sheets — not on a national calendar month. Cantaloupe and honeydew live on a separate crop. Regional dates stay source-specific.
Growing guidance is general information. Timing, spacing, and care depend on cultivar, weather, soil, and local conditions. Check the sources and adjust the plan for your garden.
Your window
Use your last-spring-frost history — not a national month.
A ZIP calculator is not live on this page. Save the bed to store the window you actually used.
Sow after frost risk at your site. Spacing lives on the watermelon hub.
Types and spacing live on growing watermelon. Cantaloupe and honeydew live on growing melons.
What the sources say — at a glance
One source per card. Facts are not averaged.
Clemson HGIC 1325 (South Carolina)
Soil at 4 in 60–65 °F; after last frost. Piedmont Apr 15–Jun 15. Coastal Apr 1–Apr 30. Fall not recommended.
Details and limits (3)
Timing
Clemson HGIC 1325 (South Carolina): Clemson lists soil temperature at the 4-inch depth of 60 to 65 °F before planting, and after-last-frost timing. Timing on their sheet — not a national plant date.
Regions
Clemson HGIC 1325 (South Carolina): watermelon planting dates on their sheet — Piedmont April 15 to June 15; Coastal April 1 to April 30. Fall not recommended in either region. South Carolina regions — not a national plant date.
Limit
South Carolina HGIC 1325. Piedmont and Coastal watermelon dates stay on this sheet. Not muskmelon and not a ZIP calendar.
Maryland Extension (Maryland)
Direct sow after frost, soil warm. Indoor 3 weeks before transplant. Maryland timing — not a national plant date.
Details and limits (2)
Timing
Maryland Extension (Maryland): direct sow when all danger of frost is past and the soil is warm. Start seeds indoors 3 weeks prior to transplanting. Maryland timing — not a national plant date.
Limit
Maryland melons garden page. After-frost timing stays Maryland. Muskmelon dates are not on this page.
UMN Extension (Minnesota)
Direct or transplant mid-May (south MN) to late June (north MN). Soil 65 °F. Minnesota timing — not a national plant date.
Details and limits (2)
Timing
UMN Extension (Minnesota): you can direct seed or transplant between mid-May in southern Minnesota and late June in northern Minnesota. Plant only after the soil temperature has reached 65 °F. Minnesota timing — not a national plant date.
Limit
Minnesota melons sheet. Mid-May to late June and 65 °F stay Minnesota. Not a ZIP calendar.
Illinois Extension (Illinois)
After frost. Soil warm. Illinois lists soil warmed above 65 °F. Illinois timing — not a national plant date.
Details and limits (2)
Timing
Illinois Extension (Illinois): plant after the soil is warm and when all danger of frost is past. Illinois lists soil warmed above 65 °F. Illinois timing — not a national plant date.
Limit
Illinois watermelon page. After-frost timing and 65 °F stay Illinois. Not a ZIP calendar.
Sources differ
Make it yours
Save the bed in the Field Book so next season is not a guess.
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When a partner is listed, it will be outbound and disclosed. Nothing to buy here. Fertilizer, soils, and pesticides stay off this slot.
When do you plant watermelon?
Compare frost and soil cues on the cited sheets. Clemson HGIC 1325 (South Carolina): soil at 4 inches 60 to 65 °F and after last frost; Piedmont April 15 to June 15; Coastal April 1 to April 30. Maryland: after frost; indoor three weeks. Minnesota: mid-May to late June; soil 65 °F. Illinois: after frost, soil warmed above 65 °F.
Do the sheets agree on a calendar month?
No. Clemson’s table is April through June in the Piedmont and April on the Coastal Plain. Maryland does not name a month — after frost. Minnesota lists mid-May to late June. Illinois does not name a month. Four cards — not averaged.
What to record in the Field Book
Save the bed with the crop and the date. You may add a photo and notes. Compare entries you have recorded with each other — not with a diagnosis from this page. If you want an identification, bring the record to local Extension.
How we know — methodology. Ranges and assertions are cited per source, not blended.