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When to Plant Melon in Clackamas County, OR

Melons are warm-season vine crops that produce sweet, juicy fruits in many varieties including muskmelon and honeydew. They need a long, hot growing season.

Clackamas County, Oregon is in USDA Zone 8a. The average last spring frost is April 14 and the first fall frost is October 28, giving you a growing season of approximately 197 days.

At an elevation of 199 feet, Clackamas County receives approximately 53.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Melon during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Melon root diseases.

Clackamas County, OR (Zone 8a) Moderate season
197 days
Last Spring Frost April 14
197 growing days
First Fall Frost October 28

Clackamas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (64 days to spare)
Start indoors: Mar 7 Transplant: Apr 18 🍅 Harvest: Jun 27 – Aug 15
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 17 Transplant: Apr 28 🍅 Harvest: Jul 7 – Aug 25
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Apr 9 Transplant: May 21 🍅 Harvest: Jul 30 – Sep 17

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 Clackamas County

How your county's soil matches Melon's growing requirements.

Soil pH

Your soil pH (5.7โ€“6.3) overlaps with Melon's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Clackamas County is excellent for Melon โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.7%) โ€” Melon will thrive.

How to Plant Melon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Melon

3
successive plantings in your 197-day season

Sow every 8 weeks. Last sowing by Jul 20 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Melon

Melon needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Melon Needs Rainfall You Supplement Action
Jan โ€” 8.3" 0" โ„๏ธ Dormant
Feb โ€” 5.3" 0" โ„๏ธ Dormant
Mar โ€” 4.8" 0" โ„๏ธ Dormant
Apr 4.3" 4" 0.3" ๐Ÿ’ง Light watering
May 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Jun 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Aug 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Sep 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Oct 4.3" 4.7" 0" โœ… Rainfall sufficient
Nov โ€” 8.2" 0" โ„๏ธ Dormant
Dec โ€” 8.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Clackamas County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Melon 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" โ€” every day above 50ยฐF 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.

Melon needs ~1,169 GDD — county provides 2,708 GDD Excellent fit

Melon Planting Timeline โ€” Clackamas County, OR

Melon Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest July 7 Jul 7 โ€“ Aug 25

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

197 days in Clackamas County

Growing Tips for Melon in Clackamas County

Direct sow Melon outdoors after April 14 in Clackamas County when soil has warmed and frost danger has passed.

Common pests for Melon 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 before transplanting. Plant on raised mounds of compost-enriched soil. Reduce watering as fruits ripen to concentrate sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Cucumber

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Melon in Clackamas County, OR?

Clackamas County is in Zone 8a with an average last frost of April 14. Plan your Melon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Clackamas County, OR?

Clackamas County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 14 and first fall frost is October 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Clackamas County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clackamas County, OR. Local conditions may vary. Last updated: April 2026.