When to Plant Watermelon in Lincoln County, WA
This month in Lincoln County, Washington
May is a pivotal month for Lincoln County, Washington gardens. Focus on these tasks first and you'll set up the rest of the season for success.
-
Plant watermelon from seed, right in the garden
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
A few tasks this May that'll pay off in June
- Transplants going out: watermelon
- Starting indoors: watermelon
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.
Lincoln County, Washington is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is September 26, giving you a growing season of approximately 130 days.
At an elevation of 2,955 feet, Lincoln County receives approximately 21.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watermelon during the growing season.
Lincoln County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.6
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 Lincoln County
How your county's soil matches Watermelon's growing requirements.
Soil pH
Your soil pH (5.5–6.6) overlaps with Watermelon's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Lincoln County is excellent for Watermelon — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Watermelon.
Organic Matter
Organic matter is excellent (4.3%) — Watermelon will thrive.
How to Plant Watermelon
Succession Planting Watermelon
Sow every 8 weeks. Last sowing by Jun 18 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 | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 2.8" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 6.5" | 1.1" | 5.4" | 🚿 Regular watering |
| Jun | 6.5" | 1" | 5.5" | 🚿 Regular watering |
| Jul | 6.5" | 0.3" | 6.2" | 🚿 Regular watering |
| Aug | 6.5" | 0.5" | 6" | 🚿 Regular watering |
| Sep | 6.5" | 0.8" | 5.7" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 3" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lincoln 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 — Lincoln County, WA
Watermelon Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 14 | Apr 14 – Apr 28 |
| Transplant Outdoors | June 2 | Jun 2 – Jun 16 |
| Direct Sow | May 26 | May 26 – Jun 16 |
| Harvest | August 11 | Aug 11 – Sep 29 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
130 days in Lincoln County
Growing Tips for Watermelon in Lincoln County
Direct sow Watermelon outdoors after May 19 in Lincoln 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.
Lincoln County receives only 22" of rain annually. Watermelon needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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.
Recommended Watermelon Varieties for Lincoln County
Compact, early melons for shorter seasons
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 Lincoln County, WA?
Lincoln County is in Zone 6b with an average last frost of May 19. Plan your Watermelon planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lincoln County, WA?
Lincoln County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is September 26.
Your Lincoln County Garden Planner — Free
A 24-page printable planner built for Lincoln County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.