Maryland · zones 6b–7b
When to plant sweet potatoes in Maryland.
Sow or transplant between May 15 to Jun 29 in a typical year, keyed to Maryland's median last frost around Apr 8. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Sweet Potatoes dates for a typical Maryland season.
1 · Start indoors
Apr 3 to May 18
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
May 15 to Jun 29
Keyed to the ~Apr 8 last frost. Sow 3" deep, 14" apart.
Harvest
~110 days later
~2.5 lb per plant over ~1 weeks.
Maryland spans more than one climate: Zone 7 is the most common zone, but the state runs 6b 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 Maryland: watch for
The pests that find sweet potatoes here.
A middle-length season, about 210 frost-free days, means sweet potato overlaps wireworms & white grubs for a stretch each summer. Check plants every week or two and treat early.
Wireworms & white grubs
Shallow holes and grooves chewed into the roots, found only at digging time.
Organic fix: Avoid planting into ground that was in sod last year; rotate away from grassy beds.
Clusters on the tender growing tips of new vines.
Organic fix: Hose them off in the morning, or use insecticidal soap.
Black rot
Dry, firm dark patches on the roots, usually found at harvest or in storage, with a sweet fruity smell.
Organic fix: Start from clean slips cut well above the soil line, never save roots from a bad crop, and rotate 3 years.
Your season math: Maryland gives sweet potatoes about 210 frost-free days, and it needs roughly 110 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting sweet potatoes in Maryland: questions
When should I plant sweet potatoes in Maryland?+
In a typical Maryland year, sow sweet potatoes or set out transplants between May 15 to Jun 29, keyed to the state's median last frost around Apr 8. Your exact dates shift with your ZIP code and microclimate.
When do I start sweet potatoes seeds indoors in Maryland?+
Start seeds inside about 6 weeks before set-out: roughly Apr 3 to May 18 for a typical Maryland season.
What USDA zone is Maryland?+
Maryland spans zones 6b–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 sweet potatoes 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.