Washington DC · zones 7b–7b
When to plant watermelon in Washington DC.
Sow between Apr 26 to Jun 12 in a typical year, keyed to Washington DC's median last frost around Apr 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Watermelon dates for a typical Washington DC season.
Direct sow
Apr 26 to Jun 12
Keyed to the ~Apr 5 last frost. Sow 1" deep, 36" apart.
Harvest
~85 days later
~20 lb per plant over ~3 weeks.
Washington DC spans more than one climate: Zone 7 is the most common zone, but the state runs 7b to 7b. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In Washington DC: watch for
The pests that find watermelon here.
A middle-length season, about 217 frost-free days, means watermelon overlaps cucumber beetles for a stretch each summer. Check plants every week or two and treat early.
Striped or spotted beetles chewing leaves, blossoms and rinds.
Organic fix: Row cover until the first female flowers open, then hand-pick in the morning.
Clusters on the growing tips; sticky film on the leaves below.
Organic fix: Hose them off, or use insecticidal soap.
Anthracnose & gummy stem blight
Dark sunken spots on leaves and fruit after a humid stretch.
Organic fix: Rotate away from cucurbits, keep foliage dry, remove infected vines.
Your season math: Washington DC gives watermelon about 217 frost-free days, and it needs roughly 85 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting watermelon in Washington DC: questions
When should I plant watermelon in Washington DC?+
In a typical Washington DC year, sow watermelon between Apr 26 to Jun 12, keyed to the state's median last frost around Apr 5. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Washington DC?+
Washington DC spans zones 7b–7b, mostly zone 7. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many watermelon plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.