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When to Plant Parsley in Placer County, CA

Placer County, California Zone 9b May

May in Placer County, California — your action list

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

Avg. last frost April 22
Avg. first frost November 9
Soil temp (4") 72°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Start parsley under lights

    You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.

Looking ahead to June
  • First harvests: parsley

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Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

Placer County, California is in USDA Zone 9b. The average last spring frost is April 22 and the first fall frost is November 9, giving you a growing season of approximately 201 days.

At an elevation of 651 feet, Placer County receives approximately 25.3 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Parsley during the growing season.

Placer County, CA (Zone 9b) Long season
201 days
Last Spring Frost April 22
201 growing days
First Fall Frost November 9

Placer County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Mar 17 Transplant: Apr 7 🍅 Harvest: Jun 9 – Aug 11
Recommended (50%) ✓ Fits season (82 days to spare)
Start indoors: Mar 25 Transplant: Apr 15 🍅 Harvest: Jun 17 – Aug 19
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Apr 30 Transplant: May 21 🍅 Harvest: Jul 23 – Sep 24

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 Placer County

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

Soil pH

Your soil pH (6.6–7.2) overlaps with Parsley's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Parsley.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Parsley.

How to Plant Parsley

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Succession Planting Parsley

3
successive plantings in your 201-day season

Sow every 6.9 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Sep 14.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.5″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 540 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Parsley

Parsley needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Parsley Needs Rainfall You Supplement Action
Jan 5.2" 0" ❄️ Dormant
Feb 5.3" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 2.6" 1.7" 0.9" 💧 Light watering
May 2.6" 0.7" 1.9" 🚿 Regular watering
Jun 2.6" 0.1" 2.5" 🚿 Regular watering
Jul 2.6" 0" 2.6" 🚿 Regular watering
Aug 2.6" 0" 2.6" 🚿 Regular watering
Sep 2.6" 0.2" 2.4" 🚿 Regular watering
Oct 2.6" 1.1" 1.5" 🚿 Regular watering
Nov 2.6" 2.4" 0.2" 💧 Light watering
Dec 4.4" 0" ❄️ Dormant

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

Parsley 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.

Parsley needs ~962 GDD — county provides 2,763 GDD Excellent fit

Parsley Planting Timeline — Placer County, CA

Parsley Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Harvest June 17 Jun 17 – Aug 19
Fall Sowing September 14 Sep 14 – Sep 28

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.6"/week · 1-2 times/week

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

201 days in Placer County

Growing Tips for Parsley in Placer County

Direct sow Parsley outdoors after April 22 in Placer County when soil has warmed and frost danger has passed.

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

General growing tips

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Parsley in Placer County, CA?

Placer County is in Zone 9b with an average last frost of April 22. Plan your Parsley planting based on this frost date — see the calendar above for exact timing.

What planting zone is Placer County, CA?

Placer County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 22 and first fall frost is November 9.

🌱

Your Placer County Garden Planner — Free

A 24-page printable planner built for Placer 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 Placer 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.