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When to Plant Pumpkin in Lassen County, CA

Lassen County, California Zone 7a May

Top priorities for Lassen County, California gardeners in May

A quick May briefing for Lassen County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 28
Avg. first frost September 29
Soil temp (4") 58°F
Watering Critical
Pest pressure Low
Daylight 14.3 hrs
June prep starts now
  • Transplants going out: pumpkin
  • Direct-sowing: pumpkin
  • Starting indoors: pumpkin

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Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Lassen County, California is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 29, giving you a growing season of approximately 124 days.

At an elevation of 1,854 feet, Lassen County receives approximately 43.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Lassen County, CA (Zone 7a) Short season
124 days
Last Spring Frost May 28
124 growing days
First Fall Frost September 29
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Lassen County Soil Profile

Soil Type

Loam

Soil pH

6.1-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 20 Transplant: Jun 1 🍅 Harvest: Aug 31 – Oct 19
Recommended (50%) ✗ May not fit
Start indoors: Apr 30 Transplant: Jun 11 🍅 Harvest: Sep 10 – Oct 29
Safe Start (90%) ✗ May not fit
Start indoors: May 22 Transplant: Jul 3 🍅 Harvest: Oct 2 – Nov 20

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 Lassen County

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

Soil pH

Your soil pH (6.1–7.5) is within Pumpkin's preferred range (6.0–7.5).

Soil Texture

The loam soil in Lassen County is excellent for Pumpkin — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Pumpkin.

How to Plant Pumpkin

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

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Pumpkin

Pumpkin needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Pumpkin Needs Rainfall You Supplement Action
Jan 9.2" 0" ❄️ Dormant
Feb 9.8" 0" ❄️ Dormant
Mar 7.7" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 5.6" 1" 4.6" 🚿 Regular watering
Jun 5.6" 0.2" 5.4" 🚿 Regular watering
Jul 5.6" 0" 5.6" 🚿 Regular watering
Aug 5.6" 0" 5.6" 🚿 Regular watering
Sep 5.6" 0.5" 5.1" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 3.9" 0" ❄️ Dormant
Dec 6.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Lassen County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Pumpkin 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.

Pumpkin needs ~1,332 GDD — county provides 1,612 GDD Good fit

Pumpkin Planting Timeline — Lassen County, CA

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors April 30 Apr 30 – May 14
Transplant Outdoors June 11 Jun 11 – Jun 25
Direct Sow June 4 Jun 4 – Jun 25
Harvest September 10 Sep 10 – Oct 29

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Natural rainfall sufficient

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

124 days in Lassen County

Growing Tips for Pumpkin in Lassen County

Direct sow Pumpkin outdoors after May 28 in Lassen County when soil has warmed and frost danger has passed.

Your 124.0-day growing season in Lassen County is tight for Pumpkin (85.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Pumpkin in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pumpkin in Lassen County, CA?

Lassen County is in Zone 7a with an average last frost of May 28. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lassen County, CA?

Lassen County, California is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 29.

🌱

Your Lassen County Garden Planner — Free

A 24-page printable planner built for Lassen County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.