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When to Plant Parsnip in Butte County, CA

Butte County, California Zone 9b May

What to do in May

Your garden in Butte County, California is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 20
Avg. first frost November 10
Soil temp (4") 75°F
Watering Critical
Pest pressure High
Daylight 14.2 hrs

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Parsnips are a sweet, nutty root vegetable that develops best flavor after exposure to frost. They require a long growing season but reward patient gardeners.

Butte County, California is in USDA Zone 9b. The average last spring frost is April 20 and the first fall frost is November 10, giving you a growing season of approximately 204 days.

At an elevation of 144 feet, Butte County receives approximately 44.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Parsnip during the growing season.

Butte County, CA (Zone 9b) Long season
204 days
Last Spring Frost April 20
204 growing days
First Fall Frost November 10
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Butte County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Transplant: Mar 26 🍅 Harvest: Jul 9 – Aug 20
Recommended (50%) ✓ Fits season (57 days to spare)
Transplant: Apr 20 🍅 Harvest: Aug 3 – Sep 14
Safe Start (90%) ✓ Fits season (57 days to spare)
Transplant: May 24 🍅 Harvest: Sep 6 – Oct 18

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 Butte County

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

Soil pH

Your soil pH (6.8–7.7) is more alkaline than Parsnip prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Parsnip.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Parsnip.

How to Plant Parsnip

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 823 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Parsnip

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

Month Parsnip Needs Rainfall You Supplement Action
Jan 9.7" 0" ❄️ Dormant
Feb 9.9" 0" ❄️ Dormant
Mar 6.9" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 2.1" 2.2" 🚿 Regular watering
Nov 4.3" 3.7" 0.6" 💧 Light watering
Dec 7.8" 0" ❄️ Dormant

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

Parsnip 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.

Parsnip needs ~2,012 GDD — county provides 3,570 GDD Excellent fit

Parsnip Planting Timeline — Butte County, CA

Parsnip Planting Calendar

Activity When Date Range
Direct Sow March 30 Mar 30 – Apr 20
Harvest July 13 Jul 13 – Aug 24
Fall Sowing September 15 Sep 15 – Sep 29

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Direct Sow
April Direct Sow
May
June
July Harvest
August Harvest
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

100–130 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

204 days in Butte County

Growing Tips for Parsnip in Butte County

Direct sow Parsnip outdoors after April 20 in Butte County when soil has warmed and frost danger has passed.

Common pests for Parsnip in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Use only fresh seed as parsnip seed viability declines rapidly. Sow directly in spring in deeply worked soil. Leave roots in the ground through winter for sweetest flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsnip in Butte County, CA?

Butte County is in Zone 9b with an average last frost of April 20. Plan your Parsnip planting based on this frost date — see the calendar above for exact timing.

What planting zone is Butte County, CA?

Butte County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 20 and first fall frost is November 10.

🌱

Your Butte County Garden Planner — Free

A 24-page printable planner built for Butte County (Zone 9b). 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 Butte 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.