Washington DC · zones 7b–7b
When to plant basil in Washington DC.
Sow or transplant between Apr 26 to Jul 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
Basil dates for a typical Washington DC season.
1 · Start indoors
Mar 15 to May 31
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Apr 26 to Jul 12
Keyed to the ~Apr 5 last frost. Sow 0.25" deep, 8" apart.
Harvest
~40 days later
~0.5 lb per plant over ~12 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 basil here.
A middle-length season, about 217 frost-free days, means basil overlaps aphids for a stretch each summer. Check plants every week or two and treat early.
Fine webbing and pale stippling in hot, dry spells.
Organic fix: Spray the undersides with water, then insecticidal soap or neem.
Yellowing with gray fuzz underneath, or white powder on top.
Organic fix: Space for airflow, water at the base, spray neem.
Metallic beetles chewing basil and mint leaves to lace.
Organic fix: Handpick into soapy water in the morning; neem.
Your season math: Washington DC gives basil about 217 frost-free days, and it needs roughly 40 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting basil in Washington DC: questions
When should I plant basil in Washington DC?+
In a typical Washington DC year, sow basil or set out transplants between Apr 26 to Jul 12, keyed to the state's median last frost around Apr 5. Your exact dates shift with your ZIP code and microclimate.
When do I start basil seeds indoors in Washington DC?+
Start seeds inside about 6 weeks before set-out: roughly Mar 15 to May 31 for a typical Washington DC season.
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 basil 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.