When to Plant Watermelon in Arlington County, VA
Arlington County, Virginia gardeners: here's your May plan
We've pulled the most time-sensitive tasks for Arlington County, Virginia this May and put them front and centre. Tackle them in order.
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Sow watermelon in trays indoors
Starting these indoors now means sturdy transplants ready the moment your soil warms up.
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.
Arlington County, Virginia is in USDA Zone 8a. The average last spring frost is April 10 and the first fall frost is October 31, giving you a growing season of approximately 204 days.
At an elevation of 284 feet, Arlington County receives approximately 46.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Watermelon during the growing season.
Arlington County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.8
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.
Soil Compatibility in Arlington County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (5.3–6.8) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Arlington County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Watermelon.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jul 23 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Watermelon
Watermelon needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Watermelon Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.8" | 0" | ❄️ Dormant |
| Mar | — | 5" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| May | 6.5" | 3.3" | 3.2" | 💧 Light watering |
| Jun | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Jul | 6.5" | 4.5" | 2" | 💧 Light watering |
| Aug | 6.5" | 4.9" | 1.6" | 💧 Light watering |
| Sep | 6.5" | 4" | 2.5" | 💧 Light watering |
| Oct | 6.5" | 2.7" | 3.8" | 🚿 Regular watering |
| Nov | — | 3.5" | 0" | ❄️ Dormant |
| Dec | — | 3.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Arlington County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Watermelon Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Watermelon Planting Timeline — Arlington County, VA
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 17 | Apr 17 – May 8 |
| Harvest | July 3 | Jul 3 – Aug 21 |
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 | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 1-2 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
204 days in Arlington County
Growing Tips for Watermelon in Arlington County
Direct sow Watermelon outdoors after April 10 in Arlington County when soil has warmed and frost danger has passed.
Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Watermelon in Other Locations
Frequently Asked Questions
When should I plant Watermelon in Arlington County, VA?
Arlington County is in Zone 8a with an average last frost of April 10. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Arlington County, VA?
Arlington County, Virginia is in USDA Hardiness Zone 8a. The average last spring frost is April 10 and first fall frost is October 31.
Your Arlington County Garden Planner — Free
A 24-page printable planner built for Arlington County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.