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When to Plant Carrots in Franklin County, WA

Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.

Franklin County, Washington is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 23, giving you a growing season of approximately 193 days.

At an elevation of 1,556 feet, Franklin County receives approximately 15.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Carrots during the growing season. With low rainfall, drip irrigation is essential for growing Carrots successfully. Mulch heavily to conserve soil moisture.

Franklin County, WA (Zone 7a) Moderate season
193 days
Last Spring Frost April 13
193 growing days
First Fall Frost October 23

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 3 – Jul 8
Recommended (50%) ✓ Fits season (95 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Jul 20
Safe Start (90%) ✓ Fits season (83 days to spare)
Transplant: May 10 🍅 Harvest: Jul 12 – Aug 16

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 Franklin County

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

Soil pH

Your soil pH (5.6โ€“6.6) overlaps with Carrots's range (6.0โ€“6.8), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) โ€” Carrots will thrive.

How to Plant Carrots

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Carrots

3
successive plantings in your 193-day season

Sow every 6.9 weeks. Last sowing by Aug 04 to harvest before frost.

For a dedicated fall crop, sow by Aug 14.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 787 gal / 100 sq ft

Monthly Watering Guide for Carrots

Carrots needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Carrots Needs Rainfall You Supplement Action
Jan โ€” 2.5" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 1.4" 0" โ„๏ธ Dormant
Apr 3.5" 1.2" 2.3" ๐Ÿšฟ Regular watering
May 3.5" 1" 2.5" ๐Ÿšฟ Regular watering
Jun 3.5" 0.6" 2.9" ๐Ÿšฟ Regular watering
Jul 3.5" 0.2" 3.3" ๐Ÿšฟ Regular watering
Aug 3.5" 0.3" 3.2" ๐Ÿšฟ Regular watering
Sep 3.5" 0.6" 2.9" ๐Ÿšฟ Regular watering
Oct 3.5" 1.2" 2.3" ๐Ÿšฟ Regular watering
Nov โ€” 2.2" 0" โ„๏ธ Dormant
Dec โ€” 2.7" 0" โ„๏ธ Dormant

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

Carrots 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.

Carrots needs ~1,225 GDD — county provides 3,377 GDD Excellent fit

Carrots Planting Timeline โ€” Franklin County, WA

Carrots Planting Calendar

Activity When Date Range
Direct Sow March 30 Mar 30 โ€“ Apr 20
Harvest June 1 Jun 1 โ€“ Jul 6
Fall Sowing August 14 Aug 14 โ€“ Aug 28

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Direct Sow
April Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“80 days

๐Ÿงช Soil pH

Needs 6โ€“6.8 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

193 days in Franklin County

Growing Tips for Carrots in Franklin County

Direct sow Carrots outdoors after April 13 in Franklin County when soil has warmed and frost danger has passed.

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

General growing tips

Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.

Companion Planting

Good Companions

Avoid Planting Near

  • Dill
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Carrots Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Replant roots for 2nd year flowers. Harvest umbels when brown.
Storage Store airtight; viable 3 years at 35ยฐF, under 50% humidity.

Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial โ€” requires two seasons.

Frequently Asked Questions

When should I plant Carrots in Franklin County, WA?

Franklin County is in Zone 7a with an average last frost of April 13. Plan your Carrots planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Franklin County, WA?

Franklin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 23.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Franklin County gardeners in Zone 7a 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 Franklin County, WA. Local conditions may vary. Last updated: April 2026.