When to Plant Zucchini in Malheur County, OR
Zucchini is an incredibly prolific summer squash that can produce an abundance of fruit from just a few plants. It is versatile in the kitchen from grilling to baking.
Malheur County, Oregon is in USDA Zone 6a. The average last spring frost is May 18 and the first fall frost is September 29, giving you a growing season of approximately 134 days.
At an elevation of 2,676 feet, Malheur County receives approximately 17.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Zucchini during the growing season. With low rainfall, drip irrigation is essential for growing Zucchini successfully. Mulch heavily to conserve soil moisture.
Malheur County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.3
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 Malheur County
How your county's soil matches Zucchini's growing requirements.
Soil pH
Your soil pH (5.4–6.3) is more acidic than Zucchini prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Malheur County is excellent for Zucchini — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Zucchini.
Organic Matter
Organic matter is excellent (5.6%) — Zucchini will thrive.
How to Plant Zucchini
Succession Planting Zucchini
Sow every 5.1 weeks. Last sowing by Jul 31 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Zucchini
Zucchini needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.
| Month | Zucchini Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 1.2" | 0" | ❄️ Dormant |
| May | 5.2" | 0.9" | 4.3" | 🚿 Regular watering |
| Jun | 5.2" | 0.7" | 4.5" | 🚿 Regular watering |
| Jul | 5.2" | 0.3" | 4.9" | 🚿 Regular watering |
| Aug | 5.2" | 0.3" | 4.9" | 🚿 Regular watering |
| Sep | 5.2" | 0.8" | 4.4" | 🚿 Regular watering |
| Oct | — | 1.4" | 0" | ❄️ Dormant |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 3.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Malheur County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Zucchini 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.
Zucchini Planting Timeline — Malheur County, OR
Zucchini Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 13 | Apr 13 – Apr 27 |
| Transplant Outdoors | June 1 | Jun 1 – Jun 15 |
| Direct Sow | May 25 | May 25 – Jun 15 |
| Harvest | July 20 | Jul 20 – Sep 14 |
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 | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1.2"/week · 2-3 times/week
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 6a
📆 Growing Season
134 days in Malheur County
Growing Tips for Zucchini in Malheur County
Direct sow Zucchini outdoors after May 18 in Malheur County when soil has warmed and frost danger has passed.
Common pests for Zucchini in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
Malheur County receives only 18" of rain annually. Zucchini needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow after last frost. Harvest when fruits are 6-8 inches long for best flavor and texture. Check plants daily in summer as fruits can double in size overnight.
Recommended Zucchini Varieties for Malheur County
Quick-producing varieties for shorter seasons
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Zucchini in Other Locations
Frequently Asked Questions
When should I plant Zucchini in Malheur County, OR?
Malheur County is in Zone 6a with an average last frost of May 18. Plan your Zucchini planting based on this frost date — see the calendar above for exact timing.
What planting zone is Malheur County, OR?
Malheur County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is May 18 and first fall frost is September 29.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Malheur County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.
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