Washington DC · zones 7b–7b
When to plant tomatoes in Washington DC.
Sow or transplant between Apr 12 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
Tomatoes dates for a typical Washington DC season.
1 · Start indoors
Mar 1 to May 1
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Apr 12 to Jun 12
Keyed to the ~Apr 5 last frost. Sow 0.25" deep, 24" apart.
Harvest
~73 days later
~12 lb per plant over ~8 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 tomatoes here.
A middle-length season, about 217 frost-free days, means tomato, slicing overlaps tomato hornworm for a stretch each summer. Check plants every week or two and treat early.
Big green caterpillars strip leaves and leave black droppings.
Organic fix: Handpick at dusk; spray Bt on the young ones.
Clusters on new growth, sticky leaves, curling tips.
Organic fix: Blast with water, then insecticidal soap or neem.
Dark spots with concentric rings, starting on the lowest, oldest leaves.
Organic fix: Remove affected leaves, mulch to stop soil splash, space for airflow.
Greasy, water-soaked blotches in cool, wet spells. No rings, and not bottom-up.
Organic fix: Pull infected plants fast, keep leaves dry, use neem as a preventive.
Septoria leaf spot
Many small tan spots with dark brown edges, low leaves first, no rings inside.
Organic fix: Strip the lowest leaves, mulch against soil splash, stake for airflow.
Your season math: Washington DC gives tomatoes about 217 frost-free days, and it needs roughly 73 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting tomatoes in Washington DC: questions
When should I plant tomatoes in Washington DC?+
In a typical Washington DC year, sow tomatoes or set out transplants between Apr 12 to Jun 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 tomatoes seeds indoors in Washington DC?+
Start seeds inside about 6 weeks before set-out: roughly Mar 1 to May 1 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 tomatoes 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.