When to Plant Watermelon in Baltimore County, MD
Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.
Baltimore County, Maryland is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is November 6, giving you a growing season of approximately 217 days.
At an elevation of 641 feet, Baltimore County receives approximately 49.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Watermelon during the growing season.
Baltimore County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-7
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Watermelon Planting Timeline — Baltimore County, MD
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Harvest | June 26 | Jun 26 – Aug 14 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
70–100 days
Soil pH
6 – 7.5
USDA Zone
Zone 7a
Growing Season
217 days
Growing Tips for Baltimore County
Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Baltimore County, MD?
Baltimore County is in Zone 7a with an average last frost of April 3. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Baltimore County, MD?
Baltimore County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is April 3 and first fall frost is November 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Baltimore County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.
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