When to Plant Carrots in Jefferson County, WA
What to do in May
Each item below is timed to Jefferson County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.
A few tasks this May that'll pay off in June
- First harvests: carrots
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.
Jefferson County, Washington is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 29, giving you a growing season of approximately 198 days.
At an elevation of 205 feet, Jefferson County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Carrots during the growing season.
Jefferson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.8
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 Jefferson County
How your county's soil matches Carrots's growing requirements.
Soil pH
Your soil pH (5.7–6.8) overlaps with Carrots's range (6.0–6.8), though not a perfect match.
Soil Texture
The silt loam soil in Jefferson County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Carrots.
Organic Matter
Organic matter is excellent (5.7%) — Carrots will thrive.
How to Plant Carrots
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Carrots
Sow every 6.9 weeks. Last sowing by Aug 10 to harvest before frost.
For a dedicated fall crop, sow by Aug 20.
Plant Water Budget
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 | — | 6.4" | 0" | ❄️ Dormant |
| Feb | — | 4.7" | 0" | ❄️ Dormant |
| Mar | — | 3.9" | 0" | ❄️ Dormant |
| Apr | 3.5" | 2.6" | 0.9" | 💧 Light watering |
| May | 3.5" | 2.1" | 1.4" | 💧 Light watering |
| Jun | 3.5" | 1.5" | 2" | 🚿 Regular watering |
| Jul | 3.5" | 0.5" | 3" | 🚿 Regular watering |
| Aug | 3.5" | 0.6" | 2.9" | 🚿 Regular watering |
| Sep | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Oct | 3.5" | 3.5" | 0" | ✅ Rainfall sufficient |
| Nov | — | 6.3" | 0" | ❄️ Dormant |
| Dec | — | 7.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Jefferson County). Supplement amounts are based on average rainfall — 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" — 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.
Carrots Planting Timeline — Jefferson County, WA
Carrots Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 31 | Mar 31 – Apr 21 |
| Harvest | June 2 | Jun 2 – Jul 7 |
| Fall Sowing | August 20 | Aug 20 – Sep 3 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–6.8 · Your soil: acceptable
🗺️ USDA Zone
Zone 8b
📆 Growing Season
198 days in Jefferson County
Growing Tips for Carrots in Jefferson County
Direct sow Carrots outdoors after April 14 in Jefferson 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
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.
Carrots in Other Locations
Frequently Asked Questions
When should I plant Carrots in Jefferson County, WA?
Jefferson County is in Zone 8b with an average last frost of April 14. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, WA?
Jefferson County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 29.
Your Jefferson County Garden Planner — Free
A 24-page printable planner built for Jefferson County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.